The present invention relates to a novel triketone derivative having a specific structure and a herbicide containing the triketone derivative as an active ingredient. The herbicide is effective for controlling weeds which inhibit growth of crop plants, inter alia, for paddy weeds such as Sanwa millet and Scirups juncoides.

The present invention relates to a novel triketone derivative and a herbicide containing the triketone derivative as an active ingredient. More particularly, the invention relates to a triketone derivative useful for a herbicide effective on weeds which inhibit growth of crop plants, enter alia, for paddy field weeds such as Echinochloa crus-galli and Scirups juncoides, and to a herbicide containing the triketone derivative as an active ingredient.
Herbicides are important chemicals for facilitating weed control and enhancing productivity of field and garden crops. Therefore, development of herbicides which is safe and has excellent weed-controlling property even at a low dose have been actively carried out for many years.
There is proposed a herbicide containing a triketone derivative having a bicyclic benzoyl structure as an active ingredient, for the herbicide has excellent safety to field crops and excellent weed-controlling activity to field weeds. For example, there is proposed a herbicide containing a compound disclosed in Japanese Patent No. 2579663 and International Patent Publication WO97/08164 as an active ingredient, which herbicide has an excellent weed-controlling property suitable for growth of field crops. However, a herbicide containing such a compound as an active ingredient has poor activity for controlling paddy field weeds, and disadvantageously has insufficient safety to a paddy rice plant.
In view of the foregoing, an object of the present invention is to provide a herbicide containing a triketone derivative as an active ingredient, which herbicide can control a wide range of weeds at a low dose and imparts a low level of chemical injury to cultivated crops, particularly a paddy rice plant.
In order to attain the above object, the present inventors have conducted earnest studies, and have found that a triketone derivative having a specific chemical structure can control a wide range of weeds at a low dose and imparts a low level of chemical injury to cultivated crops. The present invention has accomplished based on this finding.
The present invention includes first and second aspects as described below.
The first aspect of the present invention encompasses the following.
(1) A triketone derivative represented by formula [I-1]:
xe2x80x83wherein R represents a methyl group; each of X and Y represents a hydrogen atom, a halogen atom, a nitro group, an amino group, a cyano group, a hydroxy group, a mercapto group, xe2x80x94R1, xe2x80x94OR1, xe2x80x94SR1, xe2x80x94SO2R1, xe2x80x94NR2R3, or xe2x80x94NHCOR1, wherein R1 represents a C1-C6 alkyl group which may have a branched structure, a cyclic structure, or an unsaturated bond, a C1-C6 haloalkyl group which may have a branched structure, a cyclic structure, or an unsaturated bond, a phenyl group which may be substituted, or a benzyl group which may be substituted; each of R2 and R3 represents a hydrogen atom, a C1-C6 alkyl group which may have a branched structure, a cyclic structure, or an unsaturated bond, a C1-C6 haloalkyl group which may have a branched structure, a cyclic structure, or an unsaturated bond, a phenyl group which may be substituted, or a benzyl group which may be substituted, or R2 and R3 may be bonded to each other to form a group having a cyclic structure; M represents a hydrogen atom, an alkali metal, an alkaline earth metal, or an organic base; R4 represents a hydrogen atom or a C1-C6 alkyl group; and m is an integer between 0 and 4 inclusive; provided that not all of X, Y, and R4 simultaneously represent methyl groups.
(2) A triketone derivative represented by formula [I-2]:
xe2x80x83wherein R, X, Y, M, and m have the same definitions as described in relation to formula [I-1].
xe2x80x83(3) A triketone derivative represented by formula [I-3]:
xe2x80x83wherein R, X, M, R4, and m have the same definitions as described in relation to formula [I-1].
(4) A triketone derivative represented by formula [1-4):
xe2x80x83wherein R represents a methyl group; each of X and Y represents a hydrogen atom, a halogen atom, a nitro group, a cyano group, xe2x80x94R1, xe2x80x94OR1, xe2x80x94SR1, or xe2x80x94NR2R3, wherein R1 represents a C1-C6 alkyl group which may have a branched structure, a cyclic structure, or an unsaturated bond, a C1-C6 haloalkyl group which may have a branched structure, a cyclic structure, or an unsaturated bond, a phenyl group which may be substituted, or a benzyl group which may be substituted; each of R2 and R3 represents a hydrogen atom, a C1-C6 alkyl group which may have a branched structure, a cyclic structure, or an unsaturated bond, a C1-C6 haloalkyl group which may have a branched structure, a cyclic structure, or an unsaturated bond, a phenyl group which may be substituted, or a benzyl group which may be substituted, or R2 and R3 may be bonded to each other to form a group having a cyclic structure; Z represents xe2x80x94OR1, xe2x80x94SOpR1, xe2x80x94A(CH2)nQR1, xe2x80x94NR2R3, xe2x80x94N(OR1)R2, xe2x80x94O(Cxe2x95x90O)R1, xe2x80x94O(Cxe2x95x90O)OR1, xe2x80x94O(Cxe2x95x90O)SR1, xe2x80x94O(Cxe2x95x90O)NR2R3, or xe2x80x94O(Cxe2x95x90S)NR2R3 (wherein R1, R2, and R3 have the same definitions as described in relation to X and Y, each of A and Q represents an oxygen atom or a sulfur atom, p is 0, 1, or 2, n is 1 or 2), xe2x80x94OM (wherein M represents a hydrogen atom, an alkali metal, an alkaline earth metal, or an organic base), or a halogen atom; and m is an integer between 0 and 4 inclusive.
(5) A triketone derivative according to (4), wherein Z represents an xe2x80x94OM group (wherein M represents a hydrogen atom, an alkali metal, an alkaline earth metal, or an organic base).
(6) A triketone derivative according to any one of (1), (2), (4), and (5), wherein Y represents a hydrogen atom, a C1-C6 alkyl group, or a halogen atom.
(7) A triketone derivative according to any one of (1), (2), (4), and (5), wherein Y represents a hydrogen atom or a methyl group.
(8) A triketone derivative according to any one of (2), (4), and (5), wherein Y represents a hydrogen atom.
(9) A triketone derivative according to any one of (1) to (8), wherein X represents xe2x80x94R1, xe2x80x94OR1, or xe2x80x94SR1.
(10) A triketone derivative according to (1) or (9), wherein X represents a halogen atom or a methyl group.
(11) A triketone derivative according to any one of (1) to
(10), wherein M represents a hydrogen atom.
(12) A herbicide containing a triketone derivative as recited in any one of (1) to (11) as an active ingredient.
(13) A herbicide for use in cultivation of a paddy rice plant, which herbicide contains a triketone derivative as recited in any one of (1) to (11) as an active, ingredient.
The second aspect of the present invention encompasses the following.
(1) A triketone derivative represented by formula [II-1]:
xe2x80x83wherein R represents a methyl group; X represents a hydrogen atom, a halogen atom, a nitro group, an amino group, a cyano group, a hydroxy group, a mercapto group, xe2x80x94R1, xe2x80x94OR1, xe2x80x94SR1, xe2x80x94SO2R1, xe2x80x94NR2R3, or xe2x80x94NHCOR1 (wherein R1 represents a C1-C6 alkyl group which may have a branched structure, a cyclic structure, or an unsaturated bond, a C1-C6 haloalkyl group which may have a branched structure, a cyclic structure, or an unsaturated bond, a phenyl group which may be substituted, or a benzyl group which may be substituted; each of R2 and R3 represents a hydrogen atom, a C1-C6 alkyl group which may have a branched structure, a cyclic structure, or an unsaturated bond, a C1-C6 haloalkyl group which may have a branched structure, a cyclic structure, or an unsaturated bond, a phenyl group which may be substituted, or a benzyl group which may be substituted, or R2 and R3 may be bonded to each other to form a group having a cyclic structure);
G contains 3 to 5 ring-constituting atoms which form a 5- to 7-membered saturated or unsaturated condensed ring including two carbon atoms of the benzene ring adjacent to G, wherein two or less ring-constituting atoms are selected from among nitrogen, oxygen, and sulfur, and the ring-constituting atoms may have one or more substituents selected from among a C1-C6 alkyl group, a C1-C6 haloalkyl group, a C1-C6 alkoxy group, a C1-C6 haloalkoxy group, a hydroxy group, a mercapto group, an oxo group, a thioxo group, a hydroxyimino group, a C1-C6 alkoxyimino group, a hydrazono group, a C1-C6 monoalkylhydrazono group, and a C1-C6 dialkylhydrazono group, and a carbon atom or the adjacent carbon atom of the ring-constituting atom may have a substituent selected from among an ethylenedioxy group, an ethylenedithio group, a propylenedioxy group, and a propylenedithio group, with these substituents optionally being substituted with a halogen atom or a C1-C6 alkyl group;
Z1 represents a halogen atom, xe2x80x94OR1, xe2x80x94SOpR1, xe2x80x94A(CH2)nQR1, xe2x80x94NR2R3, xe2x80x94N(OR1)R2, xe2x80x94O(Cxe2x95x90O)R1, xe2x80x94O(Cxe2x95x90O)OR1, xe2x80x94O(Cxe2x95x90O)SR1, xe2x80x94O(Cxe2x95x90O)NR2R3, or xe2x80x94O(Cxe2x95x90S)NR2R3 (wherein R1, R2, and R3 have the same definitions as described in relation to X, each of A and Q represents an oxygen atom or a sulfur atom, p is 0, 1, or 2, n is 1 to 3), or a halogen atom; m is an integer between 0 and 4 inclusive; and q is 1 or 2.
(2) A triketone derivative according to (1), which is represented by formula [II-2] or [II-3]:
xe2x80x83wherein R, X, G, Z1, m, and q have the same definitions as described in relation to formula [II-1].
(3) A triketone derivative according to (1) or (2), which is represented by any one of formulas [II-4] to [II-9]:
xe2x80x83wherein R, X, G, Z1, m, and q have the same definitions as described in relation to formula [II-1], each of G1 to G4 represents an optionally substituted atom that constitutes G in formula [II-1], and i is 0, 1, or 2.
(4) A triketone derivative according to any one of (1) to (3), wherein X represents a halogen atom, xe2x80x94R1, xe2x80x94OR1, or xe2x80x94SR1.
(5) A triketone derivative according to (3) or (4), wherein each of G1 to G4 represents a ring-constituting atom having one or more substituents selected from the substituent group consisting of an unsubstituted or C1-C6 alkyl group, a C1-C6 alkoxy group, an oxo group, and a C1-C6 alkoxyimino group.
(6) A triketone derivative according to any one of (1) to (5), wherein Z1 is selected from among a halogen atom, xe2x80x94OR1, xe2x80x94SOpRl, xe2x80x94A(CH2)nQR1, and xe2x80x94N(OR1)R2.
(7) A triketone derivative represented by formula [II-10]:
xe2x80x83wherein R represents a methyl group; each of X and Y represents a hydrogen atom, a halogen atom, a nitro group, a cyano group, xe2x80x94R1, xe2x80x94OR1, xe2x80x94SR1, or xe2x80x94NR2R3 (wherein R1 represents a C1-C6 alkyl group which may have a branched structure, a cyclic structure, or an unsaturated bond, a C1-C6 haloalkyl group which may have a branched structure, a cyclic structure, or an unsaturated bond, a phenyl group which may be substituted, or a benzyl group which may be substituted, each of R2 and R3 represents a hydrogen atom, a C1-C6 alkyl group which may have a branched structure, a cyclic structure, or an unsaturated bond, a C1-C6 haloalkyl group which may have a branched structure, a cyclic structure, or an unsaturated bond, a phenyl group which may be substituted, or a benzyl group which may be substituted, or R2 and R3 may be bonded to each other to form a group having a cyclic structure); Z represents xe2x80x94OR1, xe2x80x94SOpR1, xe2x80x94A(CH2)nQR1, xe2x80x94NR2R3, xe2x80x94N(OR1)R2, xe2x80x94O(Cxe2x95x90O)R1, xe2x80x94O(Cxe2x95x90O)OR1, xe2x80x94O(Cxe2x95x90O)SR1, xe2x80x94O(Cxe2x95x90O)NR2R3, or xe2x80x94O(Cxe2x95x90S)NR2R3 (wherein R1, R2, and R3 have the same definitions as described in relation to X and Y, each of A and Q represents an oxygen atom or a sulfur atom, p is 0, 1, or 2, n is 1 or 2), xe2x80x94OM (wherein M represents a hydrogen atom, an alkali metal, an alkaline earth metal, or an organic base), or a halogen atom; and m is an integer between 0 and 4 inclusive.
(8) A triketone derivative according to (7), wherein Y represents a hydrogen atom or a methyl group.
(9) A triketone derivative according to (7), wherein Y represents a hydrogen atom.
(10) A triketone derivative according to any one of (7) to (9), wherein Z represents a halogen atom, xe2x80x94OR1, xe2x80x94SOpR1, xe2x80x94A(CH2)nQR1, or xe2x80x94N(OR1)R2.
(11) A triketone derivative according to any one of (1) to
(10), wherein X represents a halogen atom or a methyl group.
(12) A herbicide containing a triketone derivative as recited in any one of (1) to (11) as an active ingredient.
(13) A herbicide for use in cultivation of a paddy rice plant, which herbicide contains a triketone derivative as recited in any one of (1) to (11) as an active ingredient.
Hereafter, various modes for carrying out the present invention will be described.
The triketone derivative of the first aspect of the present invention (may be simply referred to as xe2x80x9cthe present inventionxe2x80x9d throughout section I) is represented by chemical formula [I-1]. Of these, triketone derivatives represented by formulas [I-2] and [I-3] are preferred in that they provide a low level of chemical injury to cultivated plants and have an excellent weed-controlling effect.
When each of R1 to R3 in formulas [I-1] to [I-4] represents a C1-C6 alkyl group which may have a branched structure, a cyclic structure, or an unsaturated bond, examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an i-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an i-pentyl group, a sec-pentyl group, an n-hexyl group, and an i-hexyl group. The ethyl group, propyl groups, and butyl groups may have an unsaturated bond, and the propyl groups, butyl groups, pentyl groups, and hexyl groups may be linear, branched, or cyclic. Of these, a methyl group and an ethyl group are preferred.
When each of R1 to R3 in formulas (I-1] to [I-4] represents a C1-C6 haloalkyl group which may have a branched structure, a cyclic structure, or an unsaturated bond, examples of the haloalkyl group include the above-described alkyl groups in which some or all of the hydrogen atoms are substituted by a halogen atom such as a chlorine atom, a fluorine atom, a bromine atom, or an iodine atom. Specific examples include a chloromethyl group, a difluoromethyl group, a trichloromethyl group, a trifluoromethyl group, a 2-chloroethyl group, a 2-fluoroethyl group, a 3-chloropropyl group, and a 3-fluoropropyl group. Of these, a trifluoromethyl group and a trichloromethyl group are preferred.
When each of R1 to R3 in formulas [I-1] to [I-4] represents a phenyl group which may be substituted, examples of the phenyl group include a phenyl group, a tolyl group, an m-chlorophenyl group, a p-methoxyphenyl group, a p-nitrophenyl group, and p-cyanophenyl group. When each of R1 to R3 represents a benzyl group which may be substituted, examples of the benzyl group include a benzyl group, an xcex1-methylbenzyl group, an o-methylbenzyl group, an m-chlorobenzyl group, a p-methoxybenzyl group, a p-nitrobenzyl group, and a p-cyanobenzyl group.
When each of X and Y in formulas [I-1] to [I-4] or Z in formula [I-4] represents an xe2x80x94OR1, examples of the alkoxy group include a methoxy group, an ethoxy group, an n-propoxy group, an i-propoxy group, an n-butoxy group, an i-butoxy group, a sec-butoxy group, a tert-butoxy group, an n-pentyloxy group, an i-pentyloxy group, a sec-pentyloxy group, an n-hexyloxy group, and an i-hexyloxy group. The propoxy groups and butoxy groups may have an unsaturated bond and may be linear, branched, or cyclic. In the above-described alkoxy groups, some or all of the hydrogen atoms may be substituted by a halogen atom. Examples of such haloalkoxy groups include a chloromethyloxy group, a difluoromethyloxy group, a trichloromethyloxy group, a trifluoromethyloxy group, a 2-chloroethyloxy group, a 2-fluoroethyloxy group, a 3-chloropropyloxy group, and a 3-fluoropropyloxy group. Of these, a methoxy group, an ethoxy group, a difluoromethyloxy group, and a trifluoromethyloxy group are preferred.
When each of X and Y in formulas [I-1] to [I-4] represents an xe2x80x94SR1 group, examples of the alkylthio group include a methylthio group, an ethylthio group, an n-propylthio group, an i-propylthio group, an n-butylthio group, an i-butylthio group, a sec-butylthio group, a tert-butylthio group, an n-pentylthio group, an i-pentylthio group, an n-hexylthio group, and an i-hexylthio group. The propylthio groups and butylthio groups may have an unsaturated bond and may be linear, branched, or cyclic. In the above-described alkylthio groups, some or all of the hydrogen atoms may be substituted by a halogen atom. Examples of such haloalkylthio groups include a chloromethylthio group, a difluoromethylthio group, a trichloromethylthio group, a trifluoromethylthio group, a 2-chloroethylthio group, a 2-fluoroethylthio group, a 3-chloropropylthio group, and a 3-fluoropropylthio group. Of these, a methylthio group, an ethylthio group, and a trifluoromethylthio group are preferred.
Examples of the xe2x80x94SO2R1 group include a methylsulfonyl group, an ethylsulfonyl group, an n-propylsulfonyl group, an i-propylsulfonyl group, an n-butylsulfonyl group, an i-butylsulfonyl group, a sec-butylsulfonyl group, and a tert-butylsulfonyl group. Of these, a methylsulfonyl group and an ethylsulfonyl group are preferred.
When each of X, Y, and Z in formulas [I-1] to [I-4] represents an xe2x80x94NR2R3 group, examples thereof include a methylamino group, a dimethylamino group, an ethylamino group, a pyrrolidinyl group, and a piperidino group. Examples of the xe2x80x94N(OR1)R2 group include a methoxyamino group, a methoxymethylamino group, a benzyloxyamino group, and an allyloxyamino group.
Example of the xe2x80x94NHCOR1 include xe2x80x94NHCOCH3, xe2x80x94NHCOC2H5, xe2x80x94NHCOC3H7, and xe2x80x94NHCOC4H10.
R4 in formulas [I-1] and [1-3] represents a hydrogen atom or a C1-C6 alkyl group. Examples of the C1-C6 alkyl group include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an i-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an i-pentyl group, a sec-pentyl group, an n-hexyl group, and an i-hexyl group. Of these, a hydrogen atom and a methyl group are preferred, with a hydrogen atom being particularly preferred.
Examples of preferable X in formulas [I-1] to [I-4] include a halogen atom, xe2x80x94R1, xe2x80x94OR1, and xe2x80x94SR1, with a halogen atom and a methyl group being particularly preferred. Examples of preferable Y in formulas [I-1] to [I-4] include a hydrogen atom, a halogen atom, and xe2x80x94R1, with a hydrogen atom, a methyl group, and a fluorine atom being particularly preferred.
The number xe2x80x9cmxe2x80x9d in formulas [I-1] to [I-4] is 0-4, preferably 0-2, particularly preferably 0.
When Z in formula [I-4] represents an xe2x80x94SOPR1 group, examples thereof include alkylsulfonyl groups such as a methylsulfonyl group, an ethylsulfonyl group, a propylsulfonyl group, a butylsulfonyl group, a pentylsulfonyl group, and a hexylsulfonyl group; alkylsulfinyl groups such as a methylsulfinyl group, an ethylsulfinyl group, a propylsulfinyl group, a butylsulfinyl group, a pentylsulfinyl group, and a hexylsulfinyl group; and alkylthio groups such as a methylthio group, an ethylthio group, a propylthio group, a butylthio group, a pentylthio group, and a hexylthio group.
Examples of M contained in the xe2x80x94OM group in formulas [I-1] to [I-3] and in formula [I-4] when Z represents an xe2x80x94OM group include a hydrogen atom; alkali metal atoms such as lithium, sodium, and potassium; alkaline earth metal atoms such as magnesium, calcium, and barium; organic bases such as trimethylamine, triethylamine, and aniline. Of these, a hydrogen atom is particularly preferred as M.
When Z in a triketone derivative represented by formula [I-4] is a hydroxy group, the derivative may be tautomers having the following structures:
wherein R, R4, X, Y, and m have the same definitions as described in relation to formula [I-4]. The triketone derivative of the present invention encompasses all these tautomeric compounds and mixtures thereof.
A process for producing the triketone derivative of the present invention will next be described. First of all, an intermediate for producing the triketone derivative of the present invention; i.e., benzothiophene-2-carboxylic acid, is produced. For example, the intermediate can be effectively produced through the following steps.
(1) First Step
In the first step, Compounds (a) and (b) are used in an amount of 1 mol each to carry out the above reaction in the presence of 1 mol or more of a base to thereby obtain Compound (c). Either of Compound (a) or Compound (b) may be used in an amount in excess of equimol with respect to the other.
Examples of the base which can be used in the reaction include an alkali metal carbonate, an alkaline earth metal carbonate, and an alkali metal hydroxide. Examples of a solvent which is inert to the reaction and used in the reaction include alcohols such as methanol and ethanol; halohydrocarbons such as chloroform and dichloromethane; hydrocarbons such as hexane and toluene; N,N-dimethylformamide; and water. The reaction is carried out in the temperature range of 0xc2x0 C. to the boiling point of the employed solvent, with stirring until completion of the reaction.
Alternatively, the reaction may be carried out in a two-phase system in the presence of a quaternary ammonium salt. Furthermore, Compound (a) may be reacted with sodium hydrogensulfide or potassium hydrogensulfide, and chloroacetic acid or bromoacetic acid, to thereby obtain Compound (c).
When the substituent X or Y in Compound (c) is a leaving group, the product may be obtained as a mixture. In this case, the product is purified through a process such as distillation, recrystallization, or chromatographic purification, to thereby yield the target compound.
(2) Second Step
In the second step, Compound (c) is cyclized to form Compound (d) as shown in the above reaction. The cyclization is carried out in the presence of an acidic reagent in a catalyst amount or in an amount of equimol or more. Examples of preferred acidic reagents include hydrochloric acid, sulfuric acid, phosphorus trichloride, phosphorus pentachloride, phosphorus oxychloride, polyphosphoric acid, acetic acid, acetic anhydride, trifluoromethanesulfonic acid, trifluoromethanesulfonic anhydride, and sulfuryl chloride. The reaction may be carried out in the absence of a solvent. When a solvent is employed, examples of preferred solvents include hexane, dichloromethane, 1,2-dichloroethane, chloroform, and N,N-dimethylformamide. The reaction is carried out in the temperature range of xe2x88x9220xc2x0 C. to the boiling point of the employed solvent, with stirring until completion of the reaction.
Alternatively, Compound (c) is transformed into its acid halide, and the acid halide is reacted in the presence of a Lewis acid. In this case, the transformation is carried out by use of a halogenating agent such as oxalyl chloride or thionyl chloride in an amount of equimol or more in the absence of a solvent or in the presence of a solvent such as methylene chloride, 1,2-dichloroethane, or chloroform. The reaction is carried out in the temperature range of room temperature to the boiling point of the employed solvent, with stirring until completion of the reaction. The subsequent reaction is carried out by use of a Lewis acid such as aluminum chloride, titanium tetrachloride, or tin tetrachloride. The reaction is carried out in the temperature range of xe2x88x9220xc2x0 C. to the boiling point of the employed solvent, with stirring until completion of the reaction. When Y of Compound (d) is a hydrogen atom, the other isomer may be intermingled with the product as an impurity. In such a case, the product is purified through a method as described above.
(3) Third Step
In the third step, Compound (d) is reduced to form Compound (e) as shown in the above reaction. Examples of preferred reducing agents used in the reduction include sodium borohydride and aluminum triisopropoxide. Examples of preferred solvents include methanol, ethanol, water, dichloromethane, and toluene. The reduction is carried out in the temperature range of xe2x88x9220xc2x0 C. to the boiling point of an employed solvent, with stirring until completion of the reaction.
(4) Fourth Step
In the fourth step, Compound (e) is dehydrated to form Compound (f) as shown in the above reaction. The dehydration may be carried out in the presence of a catalyst amount of an acidic substance such as hydrochloric acid, sulfuric acid, p-toluenesulfonic acid, or Amberlist. In this case, a solvent such as benzene or toluene is preferred as a reaction solvent, in that water formed during dehydration can be removed through azeotropic distillation. The formed water is adsorbed in an adsorbent such as a molecular sieve, or is removed through azeotropic distillation with the solvent, to thereby accelerate dehydration. When such an adsorbent is used, the dehydration is carried out in the temperature range of room temperature to 50xc2x0 C. with stirring until completion of the reaction. Azeotropic distillation is carried out through refluxing with heat at the boiling point of the employed solvent until the theoretical amount of water is removed.
(5) Fifth Step
In the fifth step, Compound (f) is oxidized to form Compound (g) as shown in the above reaction. The oxidation is carried out in the presence of an organic peroxide such as hydrogen peroxide or m-chloroperbenzoic acid in an amount of 2 mol or more. In this case, a solvent such as acetic acid or methylene chloride is preferred as a reaction solvent. The oxidation is carried out in the temperature range of xe2x88x9220xc2x0 C. to 100xc2x0 C., with stirring until completion of the reaction.
(6) Sixth Step
In the sixth step, Compound (g) is hydrogenated to form Compound (h) as shown in the above reaction. The hydrogenation is carried out under similar conditions as employed for customary catalytic hydrogenation. Examples of preferred catalysts include palladium-on-active carbon, Raney nickel, and platinum oxide. In this case, a solvent such as tetrahydrofuran, methanol, ethanol, ethyl acetate, or water is preferred as a reaction solvent. The hydrogenation is carried out in a hydrogen gas atmosphere, with or without pressure, and in the temperature range of room temperature to the boiling point of the employed solvent, with stirring until completion of the reaction.
(7) Seventh Step
In the seventh step, Compound (h) is hydrolyzed to form Compound (i) as shown in the above reaction. The hydrogenation is carried out in the presence of an alkali metal hydroxide in an amount of equimol or more in a mixture of water and alcohol such as ethanol as a solvent. The hydrolysis is carried out in the temperature range of room temperature to the boiling point of the employed solvent, with stirring until completion of the reaction.
The thus-obtained intermediate, benzothiophene-2-carboxylic acid, is used in the following reaction:
wherein R, R4, X, Y, and m have the same definitions as described in relation to formula [I-1] to [I-4], to thereby produce triketone derivatives as represented by formula [I-1] to [I-3] and a triketone derivative as represented by formula [I-4] wherein Z represents a hydroxy group.
The intermediate, benzothiophene-2-carboxylic acid, is transformed into an acid halide thereof as described in relation to the above-described cyclization. The thus-formed acid halide is reacted with a diketone in the presence of an organic base such as triethylamine at 0-20xc2x0 C. in an inert organic reaction solvent such as acetonitrile, and the reaction mixture is allowed to react with stirring at room temperature in the presence of a catalyst amount of a cyanide-donor such as acetone cyanohydrin.
Furthermore, the thus-obtained triketone derivatives represented by formula [I-1] to [I-3] and triketone derivative represented by formula [I-4] wherein Z represents a hydroxy group are reacted with a compound which can substitute some or all of the hydroxy groups in accordance with reaction, e.g., reaction as described in Japanese Patent Application Laid-Open (kokai) Nos. 62-298563, 62-242755, or 63-2947, to thereby produce substituted triketone derivatives represented by formula [I-1] to [I-3] and triketone derivative represented by formula [I-4] wherein Z represents a variety of substituents.
The triketone derivative of the second aspect of the present invention (may be simply referred to as xe2x80x9cthe present inventionxe2x80x9d throughout section II) is represented by chemical formula [II-1]. Of these, triketone derivatives represented by formulas [II-2] and [II-3] are preferred. Furthermore, among the triketone derivatives represented by formulas [II-2] and [II-3], triketone derivatives represented by formulas [II-4] to [II-9] are more preferred in that they provide a low level of chemical injury to cultivated plants and have an excellent weed-controlling effect.
In the triketone derivatives represented by formulas [II-1] to [II-9], the substituent represented by X is preferably a halogen atom, an alkyl group represented by xe2x80x94R1, an alkoxy group represented by xe2x80x94OR1, or an alkylthio group represented by xe2x80x94SR1. In the triketone derivative represented by formula [II-10], the substituent Y represents a hydrogen atom or a variety of groups. Of these, a hydrogen atom and a methyl group are preferred. In the triketone derivative represented by formula [II-10], the substituent X represents a variety of groups. Of these, a halogen atom and a methyl group are preferred.
In the triketone derivative represented by formulas [II-1] to [II-10], each of the substituents Z and Z1 represents a variety of groups. Of these, a halogen atom, and xe2x80x94OR1, xe2x80x94SOpR1, xe2x80x94A(CH2)QR1, xe2x80x94NR2R31 and xe2x80x94N(OR1)R2 described below are preferred.
When each of R1 to R3 in formulas [II-1] to [II-9] represents a C1-C6 alkyl group which may have a branched structure, a cyclic structure, or an unsaturated bond, examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an i-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an i-pentyl group, a sec-pentyl group, an n-hexyl group, and an i-hexyl group. The ethyl group, propyl groups, and butyl groups may have an unsaturated bond, and the propyl groups, butyl groups, pentyl groups, and hexyl groups may be linear, branched, or cyclic. Of these, a methyl group and an ethyl group are preferred.
When each of R1 to R3 represents a C1-C6 haloalkyl group which may have a branched structure, a cyclic structure, or an unsaturated bond, examples of the haloalkyl group include the above-described alkyl groups in which some or all of the hydrogen atoms are substituted by a halogen atom such as a chlorine atom, a fluorine atom, a bromine atom, or an iodine atom. Specific examples include a chloromethyl group, a difluoromethyl group, a trichloromethyl group, a trifluoromethyl group, a 2-chloroethyl group, a 2-fluoroethyl group, a 3-chloropropyl group, and a 3-fluoropropyl group. Of these, a trifluoromethyl group is preferred.
When each of R1 to R3 represents a phenyl group which may be substituted, examples of the phenyl group include a phenyl group, a tolyl group, an m-chlorophenyl group, a p-methoxyphenyl group, a p-nitrophenyl group, and p-cyanophenyl group. When each of R1 to R3 represents a benzyl group which may be substituted, examples of the benzyl group include a benzyl group, an xcex1-methylbenzyl group, an o-methylbenzyl group, an m-chlorobenzyl group, a p-methoxybenzyl group, a p-nitrobenzyl group, and a p-cyanobenzyl group. Of these, a phenyl group and a benzyl group are preferred. When each of X, Y, and Z1 in formulas [II-1] to [II-9] represents an xe2x80x94OR1 group, examples of the alkoxy group include a methoxy group, an ethoxy group, propoxy groups, butoxy groups, pentyloxy groups, and hexyloxy groups. The propoxy groups and butoxy groups may have an unsaturated bond and may be linear, branched, or cyclic. In the above-described alkoxy groups, some or all of the hydrogen atoms may be substituted by a halogen atom. Examples of such haloalkoxy groups include a chloromethyloxy group, a difluoromethyloxy group, a trichloromethyloxy group, a trifluoromethyloxy group, a 2-chloroethyloxy group, a 2-fluoroethyloxy group, a 3-chloropropyloxy group, and a 3-fluoropropyloxy group. Of these, a methoxy group, an ethoxy group, and an isopropoxy group are preferred.
When each of X, Y, and Z1 in formulas [II-1] to [II-9] represents an xe2x80x94SR1 group, examples of the alkylthio group include a methylthio group, an ethylthio group, propylthio groups, butylthio groups, pentylthio groups, and hexylthio groups. The propylthio groups and butylthio groups may have an unsaturated bond and may be linear, branched, or cyclic. In the above-described alkylthio groups, some or all of the hydrogen atoms may be substituted by a halogen atom. Examples of such haloalkylthio groups include a chloromethylthio group, a difluoromethylthio group, a trichloromethylthio group, a trifluoromethylthio group, a 2-chloroethylthio group, a 2-fluoroethylthio group, a 3-chloropropylthio group, and a 3-fluoropropylthio group. Of these, a methylthio group, an ethylthio group, an i-propylthio group, and a t-butylthio group are preferred.
When each of X, Y, and Z1 in formulas [II-1] to [II-9] represents an xe2x80x94SOpR1 group, examples of the xe2x80x94SOpR1 group include alkylsulfonyl groups such as a methylsulfonyl group, an ethylsulfonyl group, propylsulfonyl groups, butylsulfonyl groups, pentylsulfonyl groups, and hexylsulfonyl groups; alkylsulfinyl groups such as a methylsulfinyl group, an ethylsulfinyl group, propylsulfinyl groups, butylsulfinyl groups, pentylsulfinyl groups, and hexylsulfinyl groups; and alkylthio groups such as a methylthio group, an ethylthio group, propylthio groups, butylthio groups, pentylthio groups, and hexylthio groups. Of these, a methylsulfonyl group and an ethylsulfonyl group are preferred. In addition, when each of X, Y, and Z1 in the formulas represents an xe2x80x94NR2R3 group, examples thereof include a methylamino group, a dimethylamino group, an ethylamino group, a pyrrolidinyl group, and a piperidino group. When each of X, Y, and Z1 in the formulas represents an xe2x80x94N(OR1)R2 group, examples of the xe2x80x94N(OR1)R2 group include a methoxyamino group, a methoxymethylamino group, a benzyloxyamino group, and an allyloxyamino group. Of these, a methoxymethylamino group is preferred.
The number xe2x80x9cq,xe2x80x9d the number of the substituent X, is 1 or 2, with 1 being preferred.
When Z in formula [II-10] represents an xe2x80x94O(Cxe2x95x90O)R1 group, examples include an acetoxy group and a propionyloxy group.
When each of Z and Z1 in formulas [II-1] to [II-10] represents an xe2x80x94O(Cxe2x95x90O)OR1 group, examples of the xe2x80x94O(Cxe2x95x90O)OR1 group include a methoxycarbonyloxy group, an ethoxycarbonyloxy group, and a propoxycarbonyloxy group. When each of Z and Z1 in formulas [II-1] to [II-10] represents an xe2x80x94O(Cxe2x95x90O)SR1 group, examples of the xe2x80x94O(Cxe2x95x90O)SR1 group include a methylthiocarbonyloxy group, an ethylthiocarbonyloxy group, and a propylthiocarbonyloxy group. When each of Z and Z1 in formulas [II-1] to [II-10] represents an xe2x80x94O(Cxe2x95x90O)NR1R2 group, examples of the xe2x80x94O(Cxe2x95x90O)NR1R2 group include an N-methylcarbamoyl group, an N-ethylcarbamoyl group, and an N-dimethylcarbamoyl group. When each of Z and Z1 in formulas [II-1] to [II-10] represents an xe2x80x94O(Cxe2x95x90S)NR1R2 group, examples of the xe2x80x94O(Cxe2x95x90S)NR1R2 group include an N-methylthiocarbamoyl group, an N-ethylthiocarbamoyl group, and an N-dimethylthiocarbamoyl group.
In these formulas, m is preferably 0-2, with 0 being particularly preferred.
The triketone derivative represented by formula [II-1] may be tautomers having the following structures:
wherein R, X, G, Z1, m and q have the same definitions as described in relation to formula [II-1]. The triketone derivative of the present invention encompasses all these tautomeric compounds and mixtures thereof.
Furthermore, examples of the optionally substituted ring-constituting atoms represented by G1 to G4 in formulas [II-4] to [II-9], which are described as preferable examples of G, include an unsubstituted ring-constituting atom and a ring-constituting atom which has one or two substituents selected from the group consisting of a methyl group, an oxo group, a methoxy group, an isopropyloxy group, and a methoxyimino group. In the above formulas, i is preferably 2.
The process for producing the triketone derivative of the present invention will next be described. First of all, when G in formula [II-11] forms a 5-membered ring including two carbon atoms of the benzene ring adjacent to G, an intermediate for producing the triketone derivative of the present invention, i.e., benzothiophene-2-carboxylic acid, is produced. For example, the intermediate can be effectively produced through the following steps.
(1) First Step
In the first step, Compounds (a) and (b) are used in an amount of 1 mol each to carry out the above reaction in the presence of 1 mol or more of a base to thereby obtain Compound (c). Either of Compound (a) or Compound (b) may be used in an amount in excess of equimol with respect to the other.
Examples of the base which can be used in the reaction include an alkali metal carbonate, an alkaline earth metal carbonate, and an alkali metal hydroxide. Examples of a solvent which is inert to the reaction and used in the reaction include alcohols such as methanol and ethanol; halohydrocarbons such as chloroform and dichloromethane; hydrocarbons such as hexane and toluene; and water. The reaction is carried out in the temperature range of 0xc2x0 C. to the boiling point of the employed solvent, with stirring until completion of reaction.
Alternatively, the reaction may be carried out in a two-phase system in the presence of a quaternary ammonium salt. Furthermore, Compound (a) may be reacted with sodium hydrogensulfide or potassium hydrogensulfide and chloroacetic acid or bromoacetic acid, to thereby obtain Compound (c).
When the substituent X or Y in Compound (c) is a leaving group, the product may be obtained as a mixture. In this case, the product is purified through a process such as distillation, recrystallization, or chromatographic purification, to thereby yield the target compound.
(2) Second Step
In the second step, Compound (c) is cyclized to form Compound (d) as shown in the above reaction. The cyclization is carried out in the presence of an acidic reagent in a catalyst amount or in an amount of equimol or more. Examples of preferred acidic reagents include hydrochloric acid, sulfuric acid, phosphorus trichloride, phosphorus pentachloride, phosphorus oxychloride, polyphosphoric acid, acetic acid, acetic anhydride, trifluoromethanesulfonic acid, trifluoromethanesulfonic anhydride, and sulfuryl chloride. The reaction may be carried out in the absence of a solvent. When a solvent is used, examples of preferred solvents include hexane, dichloromethane, 1,2-dichloroethane chloroform, and N,N-dimethylformamide. The reaction is carried out in the temperature range of xe2x88x9220xc2x0 C. to the boiling point of the employed solvent, with stirring until completion of the reaction.
Alternatively, Compound (c) is transformed into its acid chloride, and the acid chloride is reacted in the presence of a Lewis acid. In this case, the transformation is carried out by use of a halogenating agent such as oxalyl chloride or thionyl chloride in an amount of equimol or more in the absence of a solvent or in the presence of a solvent such as methylene chloride, 1,2-dichloroethane, or chloroform. The reaction is carried out in the temperature range of room temperature to the boiling point of the employed solvent, with stirring until completion of the reaction. The subsequent reaction is carried out by use of a Lewis acid such as aluminum chloride, titanium tetrachloride, or tin tetrachloride. The reaction is carried out in the temperature range of xe2x88x9220xc2x0 C. to the boiling point of the employed solvent, with stirring until completion of the reaction. When Y of Compound (d) is a hydrogen atom, the other isomer may be intermingled with the product as an impurity. In such a case, the product is purified through a method as described above.
(3) Third Step
In the third step, Compound (d) is reduced to form Compound (e) as shown in the above reaction. Examples of preferred reducing agents used in the reduction include sodium borohydride and aluminum triisopropoxide. Examples of preferred solvents include methanol, ethanol, water, dichloromethane, and toluene. The reduction is carried out in the temperature range of xe2x88x9220xc2x0 C. to the boiling point of the employed solvent with stirring until completion of the reaction.
(4) Fourth Step
In the fourth step, Compound (e) is dehydrated to form Compound (f) as shown in the above reaction. The dehydration may be carried out in the presence of a catalyst amount of an acidic substance such as hydrochloric acid, sulfuric acid, or p-toluenesulfonic acid. In this case, a solvent such as benzene or toluene is preferred as a reaction solvent, in that water formed during dehydration can be removed through azeotropic distillation. The formed water is adsorbed in an adsorbent such as a molecular sieve, or is removed through azeotropic distillation with the solvent, to thereby accelerate dehydration. When such an adsorbent is used, the dehydration is carried out in the temperature range of room temperature to 50xc2x0 C., with stirring until completion of the reaction. Azeotropic distillation is carried out through refluxing with heat at the boiling point of the employed solvent by the time a theoretical amount of water is removed.
(5) Fifth Step
In the fifth step, Compound (f) is oxidized to form Compound (g) as shown in the above reaction. The oxidation is carried out in the presence of an organic peroxide such as hydrogen peroxide or m-chloroperbenzoic acid in an amount of 2 mol or more. In this case, a solvent such as acetic acid or methylene chloride is preferred as a reaction solvent. The oxidation is carried out in the temperature range of xe2x88x9220xc2x0 C. to 100xc2x0 C., with stirring until completion of the reaction.
(6) Sixth Step
In the sixth step, Compound (g) is hydrogenated to form Compound (h) as shown in the above reaction. The hydrogenation is carried out under similar conditions as employed for customary catalytic hydrogenation. Examples of preferred catalysts include palladium-on-active carbon, Raney nickel, and platinum oxide. In this case, a solvent such as tetrahydrofuran, methanol, ethanol, ethyl acetate, or water is preferred as a reaction solvent. The hydrogenation is carried out in a hydrogen gas atmosphere, with or without pressure, and in the temperature range of room temperature to the boiling point of the employed solvent, with stirring until completion of the reaction.
(7) Seventh Step
In the seventh step, Compound (h) is hydrolyzed to form Compound (i) as shown in the above reaction. The hydrogenation is carried out in the presence of an alkali metal hydroxide in an amount of equimol or more in a mixture of water and alcohol such as ethanol as a solvent. The hydrolysis is carried out in the temperature range of room temperature to the boiling point of the employed solvent, with stirring until completion of the reaction.
The thus-obtained intermediate is used in the following reaction:
wherein R, X, Y, and m have the same definitions as described in relation to the above-described formulas, to thereby produce triketone derivatives as represented by the above-described formulas wherein Z represents a hydroxy group.
The intermediate carboxylic acid is transformed into an acid halide thereof as described in relation to the above-described cyclization. The thus-formed acid halide is reacted with a diketone in the presence of an organic base such as triethylamine at 0-20xc2x0 C. in an inert organic reaction solvent such as acetonitrile, and the reaction mixture is allowed to react with stirring at room temperature in the presence of a catalyst amount of a cyanide-donor such as acetone cyanohydrin.
When G in the above formulas forms a 6- or 7-membered ring including two carbon atoms of the benzene ring adjacent to G, an intermediate for producing the triketone derivative can be produced through a method described in WO94/04524, WO94/08988, or WO97/03064.
Furthermore, either one of the thus-obtained triketone derivatives represented by the above formulas wherein Z represents a hydroxy group is reacted with a compound which can substitute some or all of the hydroxy groups in accordance with a reaction described, for example, in Japanese Patent Application Laid-Open (kokai) Nos. 62-298563, 62-242755, or 63-2947, to thereby produce substituted triketone derivatives represented by the above formulas wherein Z represents a variety of substituents.
The herbicides of the first and second aspects of the present invention (may be simply referred to as xe2x80x9cthe present inventionxe2x80x9d throughout section III) contain, as an active ingredient, triketone derivatives represented by formulas [I-1] to [I-4] in the first aspect or represented by formulas as described above in the second aspect. The herbicides are produced through mixing the triketone derivative with a liquid carrier such as a solvent or a solid carrier such as a mineral powder, and are prepared into a variety of forms such as water-dispersible powder, emulsion, powder, and granules for use. During preparation of the herbicide, a surfactant is preferably added to the herbicide so as to impart properties such as an emulsifying property, dispersibility, and extendability to the herbicide.
When the herbicide of the present invention is used in the form of water-dispersible powder, the triketone derivative, a solid carrier, and a surfactant are typically mixed, in amounts of 5-55 wt. %, 40-93 wt. %, and 2-5 wt.%, respectively, to thereby prepare a composition, which serves as a herbicide.
When the herbicide of the present invention is used in the form of emulsion, the triketone derivative, a solvent, and a surfactant are typically mixed in amounts of 10-50 wt. %, 35-85 wt. %, and 5-15 wt. %, respectively, to thereby prepare a composition, which serves as a herbicide.
When the herbicide of the present invention is used in the form of powder, the triketone derivative, a solid carrier, and a surfactant are typically mixed in amounts of 1-15 wt. %, 80-97 wt. %, and 2-5 wt. %, respectively, to thereby prepare a composition, which serves as a herbicide.
When the herbicide of the present invention is used in the form of granules, the triketone derivative, a solid carrier, and a surfactant are typically admixed in amounts of 1-15 wt. %, 80-97 wt. %, and 2-5 wt. %, respectively, to thereby prepare a composition, which serves as a herbicide.
Examples of preferred solid carriers include oxides such as diatomaceous earth and slaked lime; phosphates such as apatite; sulfates such as gypsum; and mineral micropowders such as talc, pyrophyllite, clay, kaolin, bentonite, acidic terra alba, white carbon, quartz powder, and silica stone powder.
Examples of preferred organic solvents include aromatic hydrocarbons such as benzene, toluene, and xylene; chlorohydrocarbons such as o-chlorotoluene, trichloroethane, and trichloroethylnene; alcohols such as cyclohexanol, amyl alcohol, and ethylene glycol; ketones such as isophorone, cyclohexanone, and cyclohexenyl-cyclohexanone; ethers such as butyl cellosolve, diethyl ether, and methyl ethyl ether; esters such as isopropyl acetate, benzyl acetate, and methyl phthalate; amides such as dimethylformamide; and mixtures thereof.
Examples of the surfactant which can be used in the invention include anionic, nonionic, cationic, and ampholytic surfactants such as amino acid-type and betaine-type surfactants.
To the herbicide of the present invention, an ingredient having a weed-controlling activity may optionally be added other than the triketone derivative represented by formulas [I-1) to [II-10). Examples of the compound contained in such an ingredient include diphenyl ether, triazine, urea, carbamate, thiocarbamate, acid anilide, pyrazole, phosphoric acid, sulfonylurea, and oxadiazone. These ingredients may appropriately be used in combination.
Furthermore, additives such as a pesticide, a bactericide, a plant-growth-regulator, and a fertilizer may optionally be incorporated into the herbicide of the present invention.
The herbicide of the present invention is applied directly to a weed or to a field where the weed grows, before or after germination of the weed. The manner of application depends on the type of a cultivated plant or the environment of use, and a form of application such as spraying, sprinkling, water sprinkling, or injecting may be employed.
Examples of the cultivated plant to which the herbicide is applied include graminaceous plants such as rice, wheat, barley, corn, oat, and sorghum; broad-leaved crops such as soybean, cotton, beet, sunflower, and rape; fruit trees; vegetables such as fruit, root, and leaf vegetables; and turf grass.
Examples of paddy weeds to which the herbicide of the present invention applies include Alismataceae such as Alisma canaliculatum, Sagittaria trifolia, and Sagittaria pygmaea; Cyperaceae such as Cyperus difformis, Cyperus serotinus, Scirpus juncoides, and Eleocharis kuroguwai; Scrothulariaceae such as Lindernia pyxidaria; Pontenderiaceae such as Monochoria vaginalis; Potamogetonaceae such as Potamogeton distinctus; Lythraceae such as Rotala indica; and Gramineae such as Echinochloa crus-galli.
Examples of field weeds include broad-leaved weeds, graminaceous weeds, and cyperaceous weeds. Specific examples of broad-leaved weeds include Solanaceae such as Solanum nigrum and Datura stramonium; Malvaceae such as Abutilon theophrasti and Sida spinosa; Convolulaceae such as Ipomoea purpurea; Amaranthaceae such asAmaranthus lividus; Compositae such as Xanthium strumarium, Ambrosia artemisifolia, Galinsoga ciliata, Cirsium arvense, Senecio Vulgaris, and Erigeron annus; Brassicaceae such as Rorippa indica, Sinapis arvensis, and Capsella bursa-pastoris; Polygonaceae such as Polygonum bulumei and Polygonum convolvulus; Portulacaceae such as Portulaca oleracea; Chenopodiaceae such as Chenopodium alubum, Chenopodium ficiolium, and Kochia scoparia; Caryophyllaceae such as Stellaria media; Scrophulariaceae such as Veronica persica; Commelinaceae such as Commelina communis; Euphorbiaceae such as Lamium amplexicaule, Euphorbia supina, and Euphorbia maculata; Rubiaceae such as Galium spurium, Galium aparine, and Rubia akane; Vilaceae such as Viola arvensis; and Leguminosae such as Sesbania exaltata and Cassia obtusifolia. Specific examples of Graminaceous weeds include Sorghum bicolor, Panicum dichotomiflorum, Sorghum haepense, Echinochloa crus-galli, Digitaria adscendes, Avena fatua, Eleusine indica, Setaria viridis, and Alopecurus aequalis. Specific examples of Cyperaceous weeds include Cyperus rotundus and Cyperus esculentus.


An improved heliostat device for an electrooptical system in which a mirror is gimbaled in two axes for line-of-sight direction and stabilization. A half angle drive system is connected to the mirror for controlling azimuth rotation of the mirror relative to the stable body from which the mirror is mounted. The half angle drive system comprises a N-2N-speed synchro transmitter-receiver pair, with the N-speed synchro control transmitter mounted on the stable body axis, and the 2N-speed control receiver mounted on the mirror axis. This synchro transmitter-receiver pair is operable with a null error signal controlling mirror drive such that the angular rotation of the mirror is one-half that of the angular rotation of the stable body.

The present invention relates to heliostat assemblies, and more particularly to such assemblies used in electro-optical systems that are preferably adapted to be mounted in pods mounted from an air frame. The present invention is more particularly directed to the half angle drive system associated with a gimbaled mirror utilized in an electro-optical system for line-of-sight direction control. The function of an airborne heliostat electrooptical system is to provide a space stabilized line-of-sight direction capability relative to the movement of the aircraft.
A prior art stabilization system for stabilizing and maintaining a fixed line-of-sight of an optical instrument on an aircraft is described in U.S. Pat. No. 3,518,016. Such stabilization system utilizes a gimbal mounted mirror with a direct drive DC torque motor, and a pulley driven half angle drive mechanism which is gyro controlled. In other prior art, a stabilization sighting is set forth in U.S. Pat. 3,446,980, and deviations from the line-of-sight of an electro-optical system are sensed relative to a gyro spin axis, and correction signals are generated to drive the mirror and maintain the line-of-sight without the use of mechanical transfer mechanisms. Such system utilizes an autocollimating mirror to sense the deviations from the gyro spin axis, and includes correction signal means which are applied by a closed loop servo means to cause the line-of-sight to correspond to the gyro spin axis. Such electric mirror drive also utilizes half angle mechanisms for driving the mirror, but has the disadvantage of requiring a larger volume to accommodate the autocollimation function and required alignment difficulty. Such autocollimated systems have volume and configuration disadvantages because of the need for a retroreflector on the stabilized body, and the multiple optical paths required to generate the correction signals. As a result, the ratio of gimbal size to useful aperture is poor, and is generally a more complex system requiring processing of optical information to determine the error signal required to null the servo.
A heliostat which utilizes a two axis gimbal set with an elevational gimbal structure which is annular, and wherein an azimuth gimbal is also an annular structure, is set forth in copending application Ser. No. 268,546, filed May 29, 1981 and entitled "Improved Inertialy Dampened Heliostat Assembly", which application is owned by the assignee of the present invention. In such copending application, a belt driven half angle drive system is utilized which includes an inertial dampener fastened to the mechanical pulley drive mechanism which rotates the mirror. A further showing of typical half angle mechanical drive systems utilized in heliostats is seen in U.S. Pat. No. 3,951,510, also owned by the assignee of the present invention.
The aforementioned U.S. Pat. No. 3,951,510 and copending application both describe a mirror gimbaled in two axis for line-of-sight direction and stabilization in a pod mounted electro-optical system utilizing a mechanical half angle drive system for the mirror. A continuing source of angular error in such systems is due to the vibrational peaking of the mechanical drive system which is in part due to vibrational modes of the gimbal coupled to the mechanical half angle mirror drive. Error inducing vibration can result from air frame and pod vibration modes which are at the lower end of the frequency spectrum and result in base rotation of the gimbal set. It is this base rotation which must be exactly halved by the half angle mirror drive to maintain a fixed line-of-sight. Gimbal vibration modes cause mirror rotation without base rotation and thus serve to jitter the line-of-sight. An ideal mirror drive will respond to the base rotation with a conventional half angle correction, but reject motion caused by high frequency gimbal vibration modes. It is therefore desired to decouple the mirror shaft from the gimbal while continuing accurate response to base rotation.


Systems and methods are disclosed for generating device test cases for medical imaging devices, which are not only reflective of current actual field usage of the device but also provide outlook on future usage. A probabilistic model of usage patterns is generated from historic data present in the device field logs by mining the current usage patterns. A Deep Long Short Term Memory Neural Network model of the usage patterns is constructed to predict the future usage patterns. Additionally, to capture the changing trends of device usage patterns in the field, predictive models are continuously updated in real time, and the test cases generated log files by the models are integrated into an automated testing system.

Comprehensive testing of the medical devices to ensure consistent and reliable functioning is of paramount importance as hardware or software malfunctions in such devices have adverse effect on patient diagnosis process. Moreover, device failures can potentially reduce the productivity of the hospitals using them. In a conventional machine testing methodology, a field expert will prepare an operational profile, which resembles the clinical workflows that technologists perform in hospitals. An operational profile more often contains typical workflows followed for imaging of various anatomies in terms of scanning workflows and corresponding software operations. Then, the device verification team uses this profile for validating the functionalities of the machine.
There are several challenges in preparing device operation profiles comprising of comprehensive list of test scenarios. Imaging devices facilitate generating images of desired contrast by allowing the technician to modify different contrast parameters to achieve desired image contrasts. The number of such different contrast configurations used in the field is extremely high. It is required to include several such configurations in operational profiles in proportion of actual field usage.
Additionally, imaging devices enable the technologists to perform many administrative and image post-processing operations via device UI. Consequently, technologists often multi-task and work parallel on multiple patients with the help of such UI. For example, a technologist may attend to the activities like post-processing of images from the previous patient/or scan, print images, transfer images while the current scan is in progress. To ensure that medical devices perform reliably in such circumstances, it is required to include usage of all the offered UI operations in the operational profile in accordance with actual field usage.
Further, some of the advanced imaging capabilities, packaged with medical devices are compute and memory intensive, and utilizing these can potentially result in device software system hang-up or even crash. Hence, it is extremely important to include usage of those capabilities in the operation profile.
Variations in actual usage of the imaging devices in the field are another aspect, which makes envisioning comprehensive usage scenarios extremely challenging. The clinical scan sequences vary significantly based on patient's pathological conditions. For example, imaging techniques to study cellularity could be significantly different from that for analyzing brain hemorrhage. Additionally, the clinical scan sequences vary also based on hospitals' clinical practices. Moreover, hospitals continuously invent effective and improved scan sequences. Hence, there is need for extrapolating currently known scan configurations to predict future advancements and include them in the operational profile. Additionally, it is required that the operational profiles are updated continuously to capture the ongoing trends in clinical practices.
Cost and time involved in carrying out actual testing of the imaging devices impose a restriction on number of tests that can be included in an operational profile. For example, operational and maintenance cost of an MRI machine is extremely high and is estimated to be about $1000 per day. Further, average time required to complete one clinical protocol is estimated to be about 30 minutes. This implies that protocols included in the operational profiles need to succinctly represent the field usage of the imaging devices.
Imaging devices log description of all the performed scans and UI operations along with the timestamp to a log file. Further, logs contain auxiliary information to indicate start and end of clinical workflows. Event timestamps stored in log files can be used to arrange the log information into a chronological sequence of machine operations and start and end indicators can be used to extract clinical workflows. Log files, hence, are suitable for extracting insight into actual device usage in the field. Additionally, since log files can be obtained on daily basis from machine installations across the globe, they are suitable for analyzing and capturing ongoing clinical trends. Further, since log files are description of actual usage of the machine, test cases derived from log files require little validation.
The conventional testing methodology is driven by the operational profile prepared by field experts. However, those profiles are limited to experts' knowledge and often they do not adequately represent entire clinical workflows. Additionally, such profiles are rarely updated and hence may not reflect the continuously advancing clinical practices well.
In most of the busy hospitals, the technologists often multi-task and work paralleling on multiple patients or examinations. For example, a technologist may attend to the activities like post-processing of images from the previous patient/or scan, print images, transfer images while the current scan is in progress. A number of different combinations of such activities is extremely high. For example, by modifying various machine parameters a technologist can configure more than 200 unique scans. Then he/she will configure an exam by choosing a subset of such scans in a sequence that is most suitable for the current patient scenario. A typical exam will have 10 such scans, which implies that the total number of possible permutations of scans will exceed a million. Hence, it is extremely hard for an expert to identify the most probable combinations of such activities and include them in the operational profile.
Another disadvantage of the conventional testing methodologies that, often they do not include modules to predict and incorporate future usage patterns into the testing system. These methodologies are often limited to using explicitly specified test scenarios, which increases the risk of device failures when faced with unfamiliar usage patterns.
Field log files contain a wealth of information on actual usage of medical devices. However, there are a multitude of challenges in utilizing field log files to derive test usage patterns. Firstly, identifying most prominent workflows accurately is not trivial owing to variations in device usage. For example, a technician can perform same set of scans in many different orders. Further, since several machine parameters can be modified to suit patient conditions, usage patterns are often sparsely distributed. Hence, derived test patterns may not be fully representative of the actual device usage. Additionally, it is challenging to ensure that the test patterns derived by extrapolating usage patterns found in field logs align with actual clinical usage of the machine.
In light of the above-mentioned challenges in preparing operational profile and utility of the log files, there is a need for innovative testing methodologies, which seamlessly integrate the field clinical workflows and the workflows derived by extrapolating actual workflows from field log files into a testing system.
The following discloses certain improvements.

System and a method for improving reliability of medical imaging devices


A double brake structure includes a line reel rotatably provided, at least one set of centrifugal pin, a centrifugal brake ring movably provided in the centrifugal brake ring, a centrifugal assembly for making the centrifugal pin be close to an inner wall of the centrifugal brake ring and making the centrifugal pin rotate in the centrifugal brake ring when the line reel is rotating, and for automatically adjusting the kinetic friction force between the centrifugal pin and the inner wall of the centrifugal brake ring according to the speed of the line reel when the centrifugal pin contacts with the inner wall of the centrifugal brake ring, and a magnetic brake mechanism for adjusting the speed of the line reel. The present disclosure is easy to use with stable brake performance, and can achieve the function of automatic compensatory braking.

The centrifugal brake structure of the low-profile reel double brake system in the art is the general "lever" centrifugal pins provided on the spool in the industry. When it needs a centrifugal braking, you need to manually pull the centrifugal pins. When the spool is rotating with a certain angular speed, the centrifugal pins, under the centrifugal force of the centrifugal spool, will be thrown out and rub with the metal ring to brake.
Therefore, the centrifugal brake structure of the low-profile reel in the art is inconvenient to use and cannot achieve the function of automatic compensation brake, because the centrifugal pins need to be manually triggered to achieve centrifugal brake performance.

Double brake structure, low-profile reel, and fishing tackle


A centering mechanism accurately centers a probe as it moves through a pathway having a changing shape, diameter, and direction. More specifically, the invention provides a probe centering device that includes a ring shaped resilient balloon, a front stopper that fixes a location of a first side of the balloon, and a biasing mechanism that applies a biasing force to a second side of the balloon. The biasing mechanism includes a rear stopper, a spring and a pusher, wherein the spring is located between the rear stopper and the pusher and the pusher is in contact with the second side of the balloon. A flexible member is preferably provided to cover and protect the biasing mechanism.

The invention relates in general to a probe that is inserted into a pathway within the human body such as an endoscopic or cardioscopic probe. More specifically, the invention is directed to a centering mechanism for centering a probe within a pathway such as a gastrointestinal tract, artery or other vessel.
Endoscopic and cardioscopic diagnostic probes are known in the art. Conventional probes permit physicians to visually observe the interior surface of a patient""s pathway such as a gastrointestinal track (GI), artery or other vessel. To perform certain diagnostic procedures, it is preferable that the probe be placed in the center of the pathway. However, the shape diameter and direction of pathways such as the human GI tract are constantly changing, making it difficult to maintain the probe in the proper position.
It would therefore be desirable to provide a probe with a centering mechanism which centers the probe accurately as it moves through a pathway having a changing shape, diameter, and direction.
The invention provides a centering mechanism which accurately centers a probe as it moves through a pathway having a changing shape, diameter, and direction. More specifically, the invention provides a probe centering device that includes a ring shaped resilient balloon, a front stopper that fixes a location of a first side of the balloon, and a biasing mechanism that applies a biasing force to a second side of the balloon. The biasing mechanism includes a rear stopper, a spring and a pusher, wherein the spring is located between the rear stopper and the pusher and the pusher is in contact with the second side of the balloon. A flexible member is preferably provided to cover and protect the biasing mechanism.
Other advantages and features of the invention will become apparent from the following detailed description of the preferred embodiments and the accompanying drawings.


A fuel tank isolation valve (FTIV) and methods of operation are provided. The FTIV includes first and second solenoid valves with the movable valve member of one of the solenoid valves seating against a movable valve member of the other one of the solenoid valves. One of the solenoid valves may be refueling valve allowing for evacuation of fuel vapor during refueling operations as well as to allow for purging high vapor pressure within the fuel tank. One of the solenoid valves may be a proportional valve used to control the flow of fuel vapor to an intake manifold of an operating internal combustion engine as well as to reduce a vacuum generated within the fuel tank.

Fuel tank isolation valves are used to control the flow of fuel vapor within a fuel system for an internal combustion engine and particularly in sealed fuel systems to avoid release of fuel vapor into the environment.
The present application is focused on improvements over the current state of the art as it relates to fuel tank isolation valves.


Liquid crystal display device (1) based on dielectric anisotropy in such thin layers that the effective optical path length difference between the two optical states is 1/2.lambda..sub.0 after reflection. A semiconductor body provided with drive elements (12) which is completely coated with a reflective layer (24) is used as a reflective substrate (6).

The invention relates to an electro-optic display device for use in the reflection mode, comprising a layer of liquid crystalline material between a first transparent supporting plate having at least one transparent first control electrode and a second supporting plate spaced by means of spacers and comprising at least one semiconductor body having one or more switching elements for driving a picture element matrix arranged in rows and columns and having picture electrodes which can be electrically driven separately, said picture electrodes substantially completely covering the semiconductor body at least at the area of the switching elements.
A display device of the type described in the opening paragraph is known from U.S. Pat. No. 4,239,346. The electro-optic effect used in this device (dynamic scattering) is slow.

Electro-optic display device for use in the reflection mode


A solar panel mounting system including a rail and a clip. When a first notch of the rail receives a portion of a rib of the rail, the clip is positioned on the rail to receive an end of a first solar panel having a first thickness, and when a second notch of the rail receives the portion of the rib, the clip is positioned on the rail to receive an end of a second solar panel having a second thickness different than the first thickness of the first solar panel.

The industry for racks to mount solar panels (e.g., modules) on roofs is very competitive. However, because manufactures of the solar panels have not standardized, the sizes of the solar panels vary depending the manufacture. For example, the thickness (e.g., height) of a solar panel may vary depending on the manufacturer. As such, the racks for mounting the solar panels are relatively customized according to the size of the solar panel produced by the particular manufacturer. Accordingly, there remains a need for solar panel racks that are more adjustable.

Height adjustable solar panel mounting system


Various aspects of the invention relate to compositions and methods of analyzing blood plasma, blood serum, and manufacturing pools of plasma-derived products wherein an anionic surfactant is added to an aliquot of the blood plasma, blood serum, or manufacturing pool prior to analysis, and the counterion of the anionic surfactant is not sodium ion. The anionic surfactant may be, for example, lauryl sulfate. The counterion of the anionic surfactant may be, for example, lithium ion.

Various regulatory agencies including the European Medicines Agency and U.S. Food & Drug Administration require testing for a number of different viruses during the production of plasma-derived products and releasing blood components from normal blood donation including hepatitis A virus, hepatitis B virus, hepatitis C virus, human immunodeficiency virus 1 and 2, and parvovirus B19. Although parvovirus B19 infection typically does not cause chronic health problems, parvovirus B19 from high-titer plasma donations can cause severe adverse reactions in patients receiving plasma-derived products.
Plasma donations containing high titers of parvovirus B19 are frequent and can contaminate plasma pools. Contaminated plasma pools in turn allow parvovirus B19 to be transmitted by plasma-derived products including coagulation factors, fibrin sealants, and solvent/detergent treated plasma.
Parvovirus B19 titer is typically quantified by nucleic acid testing to exclude high titer donations from plasma pools, which can significantly reduce contamination and transmission. Parvovirus B19 is challenging to quantify in some plasma samples due to the aggregation of viral particles, however, and improved methods to quantify parvovirus B19 are desirable.

Method to homogenize parvovirus B19 in clinical samples


Client devices may have internet and other services available simultaneously from a number of different networks such as wide area mobile broadband networks and local area networks such as Wi-Fi and Ethernet. In cases where a client device is receiving internet service from a local area network, the client device may still need to maintain the communication link with a wide area mobile broadband network even when not actively using its services. A method and apparatus are disclosed that enable a client device with mobile broadband connection capability and at least one local area connection capability to power off its mobile broadband modem but still be connected to mobile broadband network through the internet service which the client device may receive from the local area network. Powering off the mobile broadband modem of a client device may help reduce its power consumption.

A client device as defined in the present disclosure is a device that may access voice, video, text, instant messaging, internet and other services from a number of sources including wireless communication networks, Wi-Fi, Ethernet, etc. Such client devices may include conventional devices such as a smartphone, a tablet, a feature-phone, a laptop or a desktop personal computer, etc. Other client devices may include devices that are embedded within devices that perform other functions such as an entertainment system in a home or in an automobile, a home appliance such as a refrigerator or washer/dryer, a wristwatch with a heart rate monitor, a medical device such as a blood pressure meter or insulin sensor, a utility meter, a gaming console, a camera, a navigation device, an industrial equipment, etc.
The wireless communication networks are often referred to as Wireless Wide Area Network (WWAN). The internet service offered by such networks is often referred to as mobile broadband internet or Mobile Broadband (MB) and the WWANs are often referred to as mobile broadband networks. The terms WWAN and MB are used interchangeably herein. An example of a mobile broadband network may be based on the Long Term Evolution (LTE) from the 3rd Generation Partnership Project (3GPP). The LTE technology and its evolution are often referred to as fourth generation (4G) technologies. A client device may also use any of the previous generation technologies such as "2G", "3G" from 3GPP and other standardization bodies. A client device and a network may also use future generation technologies for current and new services. A WWAN operator may deploy multiple Radio Access Technologies (RATs) such as 3GPP LTE, 3GPP Universal Mobile Telecommunications Service (UMTS), Global System for Mobile communication (GSM), Code Division Multiple Access (CDMA), Evolution Data Only/Evolution Data Optimized (EVDO), etc. Different client devices with different capabilities may connect to the WWAN using different suitable RATs for getting internet service. There may be one or more WWAN operators providing service in a particular geographic area. Each WWAN operator may use the same or different types of RATs. For providing end-to-end services, a WWAN many include, in addition to RATs, other network elements such as gateways and interfaces with other networks. Some client devices may have capability of supporting multiple Subscriber Identity Modules (SIMs) corresponding to different WWAN internet service providers. Some client devices with multiple SIMs may be able to get internet service from multiple WWANs simultaneously.
Typically, as shown in FIG. 1, a WWAN comprises one or more base stations.
Other network devices may also be employed, such as a mobile switching center (not shown). As illustrated in FIG. 1, the communication path from the base station (BS) to the client device or mobile station (MS) is referred to herein as a downlink (DL) direction or downlink channel. The communication path from the client device to the base station is referred to herein as an uplink (UL) direction or uplink channel. In some wireless communication systems, the client device communicates with the BS in both the DL and UL directions. For instance, such communication is carried out in cellular communication systems. In other wireless communication systems, the client device communicates with the base stations in only one direction, usually the DL. Such DL communication may occur in applications such as paging. Typically in a wireless communication system, the client device and the base station may transmit information in blocks of data and such a block of data is referred herein as a "message."
A base station to which a client device may be downlink synchronized and/or communicating at any given time is referred herein as the Serving Base Station (SBS). In some wireless communication systems the serving base station may be referred to as the serving cell. The base stations that are in the vicinity of the serving base station are called Neighbor Base Stations (NBS). Similarly, in some wireless communication systems a neighbor base station may be referred to as a neighbor cell.
A client device, after initially synchronizing with a cell, may switch to another cell depending on the signal conditions, network congestion, and other criteria. The process of switching from one cell to another cell by a client device is often referred to as handover (HO) or cell reselection. In some wireless communication systems handover is also referred to as handoff. Also in some wireless communication systems cell reselection is also referred to as idle mode handoff. An NBS, to which a client device may be switching over its communication from the current SBS, is herein referred to as Target Base Station (TBS). In some wireless communication systems, a target base station is normally referred to as a target cell. Sometimes, during a handover, the serving cell and the target cell may be the same and only the channel used for communication may be changed. Such a handover, in which the cell is not changed, is called as an intra-cell handover. The purpose of intra-cell handover may be that the new channel is better suited for communication than the previous channel within the same cell. Cell reselections or handovers amongst cells that use the same frequency are referred herein as intra-frequency cell reselection or handover. Cell reselections or handovers amongst cells that use different frequencies are referred herein as intra-frequency cell reselection or handover. A network may use different Radio Access Technologies (RATs) for providing various services. In a particular network, the cells of different RAT types may be overlapping or adjacent to each other. If a neighbor cell is using a RAT type that is different from the RAT type used by the serving cell, it is referred to as an inter-RAT neighbor cell.
The decision making process for handovers and cell reselections varies from one wireless communication system to another. However, the decisions are generally based on the signal conditions measurements by the client devices and reporting of those measurements to the wireless communication network by the client devices. The wireless communication network generally may influence and control the measurements and reporting process of the client device by providing parameters for the measurement and reporting process. The actual decision to perform handover may be made either by the wireless communication network or by the client device depending on the type of particular wireless communication system. On the other hand the cell reselection decisions in idle mode (i.e., when client device is not in active communication with the wireless communication network) may be generally performed autonomously by the client device. Both handovers and cell reselections may normally lead to change of cell from which the client device may access communication services. The difference between the handover procedure and cell reselection procedure may depend generally on whether a client device is engaged in an active communication with the wireless communication network. The measurements may include the Received Signal Strength Indicator (RRSI), Signal-to-Noise and Interference Ratio (SINR), the physical identities of one or more cells that may be visible or detectable by a client device, the difference between the timing of the current cell on which a client device may be camped and the timing of the neighbor cells. For example, in case of 3GPP LTE, the measurements may include Reference Signal Received Power (RSRP), Reference Signal Received Quality (RSRQ), Physical Cell Identity (PCI), etc.
Normally, certain types of system information may be required by all client devices so that they may communicate with the wireless communication network. The system information typically includes system synchronization information, system parameters, resource allocation information, paging information, etc. The wireless communication network may transmit such system information as broadcast data so that all client devices within its coverage area may be able to receive that information. Such information is herein referred to as "broadcast messages."
Typically in a wireless communication system a base station may group the system information and each group of system information may be transmitted as multiple broadcast messages and such broadcast messages are herein referred as "system parameter messages." The system parameter messages may carry important system information without which the client device may not be able to communicate with the wireless communication network. The wireless communication network may transmit these system parameter messages at regular intervals in such a way that any client device that enters its coverage area may receive these system parameter messages and may be able to communicate with the wireless communication network at the earliest possible time. Client devices that are already in the base station's coverage area may also periodically receive these system parameter messages for possible updates. Normally a client device may store the system parameter messages in its memory for the current SBS.
Typically, in wireless communication systems, most of the system parameter messages may not change frequently. For example, some system parameter messages may change once or twice a day and some system parameter messages may not change for many days.
In some wireless communication systems, when a client device switches to a new base station due to cell reselection or handover, it may be required to receive the system parameter messages for the new SBS and certain system parameter messages for the selective list of NBSs corresponding to the new SBS.
The set of all system parameter messages broadcast by a base station is herein referred to as "base station broadcast system information." The individual block of system information message may be referred to as "System Information Block (SIB)." Two or more SIBs may be grouped and sent as a single System Information (SI) message. There may be different SIBs describing different groups of system parameters such as SIB Type1 (SIB1), SIB Type2 (SIB2), etc. The SI for one or more cells may be periodically updated by the network. To ensure that the client devices are using the correct version of the SI, a field referred herein as "change-mark" is generally included in the SI messages. A client device may store the change-mark of the SIs it has decoded. If the new SI is transmitted by a cell, it may increment the change-mark to enable the client terminal to detect that it needs to acquire the newly updated SI. The change-mark of the newly acquired SI is then used as latest version for detecting any future changes in the SI. The change-mark field may be incremented in modulo arithmetic to keep the field bit-width to a minimum. For example, the change-mark may be incremented modulo-8 and the value may be represented by a 3-bit wide field.
In idle mode, a client device for the most part may turn off a majority of its circuitry to reduce power consumption. This is often referred to as "sleep" state, a sub-state within the idle mode. A client device may remain in a sleep state for a long duration and may wake up at the desired time window where it expects to receive the paging messages and certain SIBs. This alternating sequence of sleep and wake-up in idle mode is referred herein as Discontinuous Reception (DRX). The sleep and wake-up sequence may follow regular pattern and its period is often referred to as DRX cycle. The success rate for the incoming calls (e.g., mobile terminated voice calls and/or data calls) in a client device is directly related to the successful reception of paging messages. Normally, in idle mode, in addition to the reception of paging messages and SIB messages, a client device may continue to search and monitor neighbor cells. In connected mode, a client device may be actively engaged in communication with the network for data transfer in downlink, uplink, or both directions.
When a client device attempts to perform a network registration procedure to get service from a cell, it first decodes the system information broadcast in the cell. The client device may store such system information. The system information carries important information regarding the cell reselection criteria. Such information may include but not limited to the Tracking Area Identity (TAI), Public Land Mobile Network Identity (PLMN ID) which uniquely identifies a particular network operator, Closed Subscriber Group Identity (CSG ID), RAT type, neighbor cell frequencies, etc. This information may help to decide whether a cell is a "suitable cell" for the client device to avail all the services offered by it, or the cell is an "acceptable cell" where the client device may avail only limited services such as emergency calls. The client device may have to perform the network registration procedure to get service from the network and for the network to be able to page the client device for mobile terminated (incoming) calls. The network registration procedure may be typically performed by a client device with a particular cell. A group of cells in the geographic vicinity of each other may form a registration area. A registration area may be identified based on the system information of a cell. For example, the tracking area of a group of cells in a registration area may be the same.
Each base station in a wireless communication network may be identified by a unique identifier referred to herein as Cell Identity (CID). The CID of a base station may become known to a client device when it decodes SI from the base station. To avoid unnecessary updates from a client device and yet ensure the ability to reach a client device at any given time, the network may organize a group of cells into a "tracking area" and use a TAI to identify the various groups of cells. This is shown in FIG. 2 where four different tracking areas are illustrated. A cell may broadcast information about the tracking area it belongs to by including the TAI information in the system information. A client device may be required to inform the network when it begins to receive service from a cell that belongs to a tracking area that is different from the tracking area of the cells from which it was previously receiving service. The process of informing the network that the client device has begun receiving service from a cell that belongs to a new tracking area is referred herein as Tracking Area Update (TAU) procedure. With this method, a client device may perform TAU only when there is a change in TAI of the cell from which it is getting service. For example, in FIG. 2, when a client device reselects from the cell with CID=1003 to the cell with CID=1007 which has the same TAI, it may not perform TAU procedure. However, when the client device reselects from the cell with CID=1007 and TAI=200 to the cell with CID=1012 and TAI=201, it may perform TAU procedure.
Different client devices may be identified using their respective unique identities. For example, International Mobile Subscriber Identity (IMSI), Temporary Mobile Subscriber Identity (TMSI), the Media Access Control (MAC) address, the Internet Protocol (IP) address may be used for the identity. Regardless of any particular identity used, it is generically referred herein as Client Device Identity (CDI).
As long as a client device is in the same registration area, the client device may not perform network registration procedure again except that a periodic network registration update procedure may need to be performed even if the client device continues to be stationary or move within the same registration area. If the client device moves to a cell which does not belong to the registration area in which the client device is registered, then the client device may perform network registration procedure to continue to access service from the network. Similarly, as long as a client device is in the same TAI, the client device may not perform TAU procedure again except that a periodic TAU procedure may need to be performed even if the client device continues to be stationary or move within the same TAI.
When a client device is in idle mode, the network may only be aware of the location of the client device at the registration area level. In order for a network to page a client device, it may need to send the paging message in all cells belonging to the same registration area. The instances for paging message transmission, known as paging occasions (POs), are usually derived based on a client device's unique identity and the paging cycle. The network may transmit a paging message addressed to a specific client device in its specific PO. When a client device performs cell reselection, the exact instances of paging occasions may be different in the new serving cell. Depending on the exact timing of the cell reselection and the timing of the POs in the old serving cell and the new serving cell, the client device may potentially miss a paging message or may receive it with delay. A single paging message received in a single PO may include multiple paging records to page multiple client devices. Different client devices may be identified within a paging message by using their respective unique identities in the paging records. For example, International Mobile Subscriber Identity (IMSI) may be used for the identity, or in case of 3GPP LTE wireless communication system, System Architecture Evolution (SAE)-Temporary Mobile Subscriber Identity (S-TMSI) may be used.
Internet service has become ubiquitous and the means by which it is obtained varies widely. For example, internet service may be provided through a Digital Subscriber Line (DSL), a Data over Cable Service Interface Specification (DOCSIS) based internet service over cable television system (Cable Modem), a fiber optic network, a WWAN, a satellite communication network, etc. When the internet service provides high data transfer rates it is often referred to as broadband internet service. Broadband internet service is generally understood to be a service that is always on and offers data transfer rates on the order of mega-bits per second or higher for both downlink and uplink.
A client device may use internet service from one or more of the available internet service sources. A client device may access the internet service directly through one of the primary sources of internet service as mentioned earlier. Alternatively, a client device may access the internet service through a local network, which may perform distribution of the primary internet service to the users localized in a given area. Examples of such local networks include Local Area Network (LAN) using Ethernet, Wireless LAN (WLAN) commonly known as Wi-Fi, Bluetooth™, Zigbee or some other local area networking schemes. The wireless local networking schemes are collectively referred herein as Short Range Wireless Link (SRWL). The wire-line local networking schemes, such as DSL, Cable Modem, Ethernet, etc. are collectively referred herein as Short Range Cabled Link (SRCL). Both the SRWL and SRCL together are referred to as Short Range Link (SRL). When a client device is in proximity of a location where an SRL access is available, it may access the internet service using the SRL. FIG. 3 illustrates an example scenario of client devices accessing the internet service over a WLAN SRWL that is connected to a traditional wire-line internet service such as a DSL or a DOCSIS Cable Modem. The local area where WLAN service is available is often referred to as a Hotspot. The device that offers the WLAN service in a given local area is referred to as an Access Point (AP). In the present disclosure, the terms Hotspot AP or Hotspot are used interchangeably to refer to the device that offers the WLAN service in a given local area.
A Hotspot AP may be connected to the DSL or DOCSIS Cable Modem through any of the standardized interfaces such as Universal Serial Bus (USB), Ethernet, or proprietary interfaces. In some cases, the DSL or DOCSIS Cable Modem and the Hotspot AP may be part of a single physical device. In such cases, the interface between the DSL or DOCSIS Cable Modem and AP may use Secure Digital Input Output (SDIO) or another suitable interface.
As the variety of client devices has increased and the demand for MB service has increased, a device known as a mobile Hotspot is commonly used. A mobile Hotspot device includes both a modem for WWAN and a WLAN AP (Hotspot AP) to distribute the internet service to local client devices. FIG. 4 illustrates the block diagram of an example mobile Hotspot device. As shown in FIG. 4, for the chosen example, the WWAN modem and the Hotspot AP may be connected to each other via one of the standard interfaces used in the industry such as USB, SDIO, or proprietary interfaces. In another mobile Hotspot example, the WWAN modem and the WLAN AP may be an Integrated Circuit (IC) as shown in FIG. 5.
Some client devices have capability to connect with number of different sources of internet service. For example, a client device may have a WWAN modem that may be used to get mobile internet service directly from the mobile broadband network as illustrated in FIG. 6. The flow of data as shown in FIG. 6 is from the mobile broadband modem to the application processor which processes the download and upload application data and interacts with the user via the display and other elements of the user interface such as touch-screen, camera, microphone, speaker, vibrator, etc. The client device may also have a WLAN modem to access internet service over a Hotspot AP. When it is near a Hotspot AP, it may use internet service from a Hotspot as illustrated in FIG. 3. In that case the flow of data is as shown in FIG. 7 from the internet to the DSL or Cable Modem to the Hotspot AP and then to the WLAN modem and on to the application processor which processes the download and upload application data and interacts with the user via the display and other elements of the user interface such as touch-screen, camera, microphone, speaker, vibrator, etc. in the client device.
When a client device is connected to an SRL such as the WLAN for internet service, it may continue to maintain its link with the WWAN for services other than internet service. For example, a voice call or a video call to or from the phone number associated with the client device may be enabled through the WWAN while the internet service may be accessed through WLAN. The maintenance of the link with the WWAN may not necessarily require an active connection (a call or an internet service), but it may involve a number of procedures that a client device may need to perform. A client device may need to continue to receive paging messages from the WWAN in order to receive any incoming voice or video calls. A client device may need to perform measurements on SBS and NBSs as well as decode the SI from the SBS and some of the NBSs. A client device may need to perform TAU procedure with the WWAN whenever it reselects to a neighbor cell with a TAI different from a TAI of its current serving cell. A client device may need to perform registration procedure with the WWAN when it reselects to a cell in a different registration area or when a periodic registration update is required. Collectively, all the procedures performed by a client device in idle mode with WWAN are referred to as idle Radio Resource Management (RRM) procedures. In FIG. 7, the link between the WWAN modem of a client device and the WWAN is maintained for the purposes mentioned above, even when the client device is getting internet service from the WLAN.

Method and apparatus for internet based wireless communication for networks