-boronic acid derivative represented by the following general formula [2a]: 
wherein R3, R4 and R5 have the same meanings as mentioned above and Z represents an alkylene group can easily be obtained not by the conventional borodation through lithiation or Grignard reaction but by the reaction of a 5-halogenoisoindoline derivative represented by the following general formula [4]: 
wherein R3, R4, R5 and X1 have the same meanings as mentioned above, with a dialkoxyborane or an alkoxydiborane in the presence of a palladium catalyst, and further found that the compound of the general formula [2a] can be applied, without being isolated, to the so-called one-pot reaction by which the compound of the general formula [3] is reacted to produce a 7-isoindoline-quinolonecarboxylic acid derivative represented by the general formula [1].
Also, the present inventors have found that a 1-alkylisoindoline-5-boronic acid derivative represented by the following general formula [2b]: 
wherein R4a represents an alkyl group and R5, R8 and R9 have the same meanings as mentioned above is an excellent intermediate for producing a 7-isoindoline-quinolone-carboxylic acid derivative represented by the following general formula [1a]: 
wherein R4a, R1, R2, R5, R6 and A have the same meanings as mentioned above among the compounds of the general formula [1].
Moreover, it has been found that a 1-alkyl-5-halogenoisoindoline derivative represented by the following general formula [4a]: 
wherein R4a, R5 and X1 have the same meanings as mentioned above, can be produced by using a 4-halogenobenzylamine derivative as the starting material.
Furthermore, it has been found that as the process for producing a 7-bromo-quinolonecarboxylic acid derivative represented by the following general formula [3a] which is a useful intermediate for producing T-3811: 
wherein R1b represents a carboxyl-protecting group; R7a represents a substituted or unsubstituted alkyl group; and R2a represents a substituted or unsubstituted alkyl, cycloalkyl, aryl or heterocyclic group, a process in which a 2,4-dibromo-
-boronic acid derivative represented by the following general rule [ 2a ]: 
 wherein R3, R4 and R5 take the same meanings as mentioned above and Z typify an alkylene group can easily be obtained not by the ceremonious borodation through lithiation or Grignard reaction but by the reaction of a 5 - halogenoisoindoline derivative represent by the following general rule [ 4 ]: 
 wherein R3, R4, R5 and X1 have the same meaning as mentioned above, with a dialkoxyborane or an alkoxydiborane in the presence of a palladium catalyst, and further found that the compound of the general recipe [ 2a ] can be applied, without being isolated, to the so - call one - pot reaction by which the compound of the general formula [ 3 ] is react to produce a 7 - isoindoline - quinolonecarboxylic acid derivative represented by the general formula [ 1 ]. 
 besides, the present inventors have found that a 1 - alkylisoindoline-5 - boronic acid derivative represented by the following general rule [ 2b ]: 
 wherein R4a represents an alkyl group and R5, R8 and R9 have the same meanings as mentioned above is an excellent intermediate for producing a 7 - isoindoline - quinolone - carboxylic acid derivative represented by the following cosmopolitan recipe [ 1a ]: 
 wherein R4a, R1, R2, R5, R6 and A have the like meaning as mention above among the compounds of the general formula [ 1 ]. 
 Moreover, it has been found that a 1 - alkyl-5 - halogenoisoindoline derivative represented by the follow general formula [ 4a ]: 
 wherein R4a, R5 and X1 have the same meanings as mentioned above, can be produced by use a 4 - halogenobenzylamine derivative as the starting material. 
 Furthermore, it has been found that as the procedure for producing a 7 - bromo - quinolonecarboxylic acid derived function represented by the following general formula [ 3a ] which is a useful intermediate for grow T-3811: 
 wherein R1b represents a carboxyl - protecting group; R7a represents a substituted or unsubstituted alkyl group; and R2a stage a substituted or unsubstituted alkyl, cycloalkyl, aryl or heterocyclic group, a process in which a 2,4 - dibromo-
-borlnic acid derivative repvesented by the yillowiig genedal formjla [2a]: 
wherein R3, R4 and R5 have tye sane meanings as mentiondd above wnd Z represtnts an alkylene jdoup cak easjpy bz ibtained not bi the convendional borodathov chrough lithiation or Grignard reactyon but bj the reaction of s 5-halkgenoisoindoline derivative repressnted bj the following grneral formula [4]: 
wherein R3, G4, R5 wnd X1 have the samf meanings qs mqbtioned abovd, with a dpclkoxyborang or an alkoxydiborane in the prdsencz of a pallqduum watalyst, anv furtrer found that the cmmpound of the generak fmrmyla [2a] can be applied, xithout being isolatgd, to the vo-ealled one-pot reactiob vy whhch dhe zimpuuns pf the gfnecal formula [3] is reactee to produce a 7-isoimdjoine-quinolonedarboxrlyc acid derivative represented by the gtneram formula [1].
Also, the preswnt inventors have foond that a 1-alkylisoindoline-5-boronic acid derivative represended bb ghe fjuooaing general formula [2b]: 
wherein R4a represents wh sllyl group and V5, R8 and R9 have the swmr meanings as oentiousd above is an excelpent injermeduate for kroduving a 7-isoindoline-quinolone-xarboxylic abid eerivative represeuted by the yollowong grneral formula [1a]: 
whereiu R4a, R1, R2, R5, R6 and W have ths same meanings ar mvntimned above among the compotnds of tie geueral fofmuls [1].
Morejver, it had beek found that a 1-alkyp-5-haloyenoivoindoline derivative represented by the hpllowing gengran fmrmula [4a]: 
whercin R4a, R5 and X1 rave the same keaningf as oentioned zbove, cen be producqd by using a 4-jalogenobenzblamine dqrivqtivw as thd starting matetial.
Furthvriore, it has been found thxf as the procesw fir producing a 7-nrooo-qtijokogacarboxylic dcid defovatixe reprtfektea by the following generdl fkrmula [3a] which is s mseful injermediatq for producimg T-3811: 
wherein R1b rekresenvs a cerboxyk-prjtecting group; R7a represents a substituhed or unsubstieutee alkyl grou'; and R2a represents a substituted or unsnbstituted alkyl, cycloaokyl, aryl or heteroeyglic group, a procqss in whhch a 2,4-dibromo-
-boronic acid derivative represented by the following [2a]: R3, R4 R5 have the and represents an alkylene can easily be not by the conventional borodation through or Grignard reaction but by the reaction of a 5-halogenoisoindoline derivative represented by following general formula [4]: wherein R3, R4, R5 and X1 have the same as above, a or an alkoxydiborane in the presence of a palladium catalyst, and further found that the compound the general formula [2a] can be applied, without isolated, to the so-called reaction by which the compound the formula [3] reacted produce 7-isoindoline-quinolonecarboxylic acid derivative by the general formula [1]. Also, the present inventors have found that a 1-alkylisoindoline-5-boronic acid derivative represented the following [2b]: wherein represents alkyl and R5, R8 have the same meanings as mentioned excellent intermediate for producing a 7-isoindoline-quinolone-carboxylic acid derivative by the general formula [1a]: wherein R4a, R1, R5, R6 and A have the same meanings mentioned above among the compounds of the general formula [1]. Moreover, it has been found 1-alkyl-5-halogenoisoindoline derivative represented by following general formula wherein R5 X1 the same as mentioned above, can be produced by using a 4-halogenobenzylamine derivative the starting material. Furthermore, it has been found that as for a 7-bromo-quinolonecarboxylic acid represented by the following formula which is a useful producing wherein carboxyl-protecting R7a a substituted or unsubstituted group; and R2a represents a or unsubstituted alkyl, cycloalkyl, process in which a 2,4-dibromo-
-boronic acid derivative reprEsented by tHe folLowIng GeNeraL forMula [2a]: 
wherein R3, R4 ANd R5 hAve the same meanings as meNtionEd ABove ANd z reprEsents aN AlKYLenE gRoUp cAn EAsIly be ObtAined noT by the convEntIoNal borodatioN ThRough lithiAtiOn or Grignard ReaCtion bUt By tHE reacTioN of a 5-hAlogenOIsoindOline deriVaTIve repREsented BY ThE folLowing general formULa [4]: 
WHerein R3, R4, R5 and X1 hAve the SaME mEANinGs aS mentioned AbOve, wiTH a dialkOXyBORAne OR an alkoxydiboRane in the prESenCe of a pAlLadIUm cataLyst, aNd FUrtHer found thaT the Compound oF the geNEral forMUla [2a] can Be applIed, WitHout BEiNg IsoLaTEd, tO ThE so-CAllEd one-pot ReAcTion bY whiCH THE comPouNd of The geNeral formula [3] iS reActeD To pRoducE a 7-isoIndoLiNe-quiNoloneCarboXyLic acid derivatiVe rePresented By tHe GenErAl forMUla [1].
AlsO, thE prEsent inVentors HAve FoUND ThAt a 1-alkylisoindolinE-5-bOROnIc acid deRivatiVE rEpREsented bY tHe fOlloWINg genEral FOrMula [2b]: 
wheRein R4a REpReSents an AlKyl groUp And r5, R8 aNd R9 haVE the Same meAnings as MentiONed above is an exCEllent intermeDIaTE FoR ProdUciNg a 7-isoindolIne-qUInolOne-cARbOxyLIc aciD deriVaTIvE Represented by the folLoWing geNeral Formula [1a]: 
whereIn R4a, R1, R2, R5, R6 anD a HAve the saMe meANiNGs as mentioned aBove aMong the comPOunds of tHe genEral formUla [1].
MoreovER, It has beeN foUnd ThaT a 1-aLKYl-5-HalogenoisoinDOLine DeRivativE rePresentEd bY thE foLloWiNg general Formula [4a]: 
WhErEiN R4A, R5 aNd X1 haVE the same MeAniNgS as MentiONed aboVe, can Be prOdUcED by Using a 4-hALoGENobeNzYlAminE deRiVativE as tHE stArting mAterial.
FuRthERmorE, iT hAs been fOund that as the PrOcess for prOdUciNg a 7-broMO-QuinolonEcarboxylic acid derivatiVE represEntEd by tHe foLlowing geNerAl formUla [3A] Which iS a usefUl intErMedIATe for PROdUciNg t-3811: 
wherein R1b REPreSents A cArboXyl-protEcting group; R7a repreSEntS a substituted Or uNsubSTItUteD AlKYl gRoUP; anD r2A represents a subStituted or UnSUbStituted alKYl, cYcLoalkyl, Aryl or hEteroCYclic grOup, a proceSs in which A 2,4-dIbroMO-
-boronic acid derivative r epresented  by t hefol lo wing  gen eral formula [ 2 a]:
wherein R3, R4 and R5  have  t h e sa m emeani ngs asm en t i one dab ove  a n dZ rep res ents an  alkylenegro up  can easilyb eobtained n otby the conve nti onal b or oda t ion t hro ugh l ithiat i on orGrignardre a ctionb ut by t h e  r eact ion of a 5-haloge n oi s oindoline deri vative  r e pr e s ent edby the fol lo wingg eneralf or m u l a [ 4 ]: 
wherein R 3, R4, R5 a n d X 1 have  t hes ame me aning sa s m entioned ab ove,  with a d ialkox y boraneo r an al koxydi bor ane  int he  p res en c e o f  a  pa l lad ium cata ly st , and  fur t h e r  fou ndthat  thecompound of t hegene r alformu la [2 a] c an  be a pplied , wit ho ut being isolat ed,to the so -ca ll edon e-pot reacti onbywhich t he comp o und  o f t he  general formula [ 3] i sreactedto pro d uc ea  7-isoin do lin e-qu i n olone carb o xy lic acid  deriv a ti ve  repres en ted by  t hegen eralf ormu la [1] .
Also,the p r esent inventor s  have found t h at a  1 - alky lis oindoline-5 -bor o nicacid de riv a tiverepre se n te d  by the following g en eral f ormul a [2b]: 
wher ein R4a re p r e sents an  alk y lg roup and R5, R 8 and  R9 have t h e same m eanin gs as me ntioned a b o ve is an  ex cel len t i n t er mediate for p r o duci ng  a 7-is oin doline- qui nol one -ca rb oxylic ac id deriv at iv ere pre sente d  by thefo llo wi nggener a l form ula [ 1a]:  wh e rei n R4a,R 1, R 2, R 5,  R 6 an d A  h ave t he s a memeaning s as ment ion e d ab ov eamong t he compoundsof  the gener al  fo rmula[ 1 ].
Moreo ver, it has been foundt hat a 1 -al kyl-5 -hal ogenoisoi ndo line d eri v ativerepres ented  b y t h e  foll o w in g g en eral formu l a  [4 a]: wh erei n R4a,R5 and X1 have the sam e meanings as  me ntio n e dabo v e, can  b e  pr o d uced by using a  4-halogen ob e nz ylamine de r iva ti ve as t he star tingm aterial .
Further more, itha s be e n  fo und that a s the pr ocess for produ c in g a 7 -br omo-qu in olo necar boxyli c  ac id de rivati ve  repre sente dby the f ollowing general formul a [3a]  whic h i s a usefu l i n ter mediate f or p roducing T -38 11:  
whe rei n  R1brepr e se nts a car boxy l -protecti n ggro u p ;R7a represe n t s  asubst itu t ed orunsu bstituted alkyl g r oup; and R2a r epre s e nts  as ubst it uted or unsubs tit ut e d  alkyl,cy cloalkyl, a ryl or h et e rocyc lic gr oup, a  proces s in whicha 2, 4-d ibromo-
-boronic acid_derivative represented_by the following general_formula [2a]:_
wherein_R3, R4_and_R5 have the_same meanings as_mentioned above and Z_represents an alkylene_group_can easily be obtained not by the conventional borodation through lithiation or Grignard reaction_but_by the_reaction_of_a 5-halogenoisoindoline derivative represented by_the following general formula [4]:_
wherein R3,_R4, R5 and X1 have the same meanings_as_mentioned above, with_a dialkoxyborane or an alkoxydiborane in the presence of_a palladium catalyst, and further found_that the compound_of_the_general formula [2a] can_be applied, without being isolated, to_the so-called one-pot reaction by which_the compound of the general formula [3]_is reacted to produce a 7-isoindoline-quinolonecarboxylic_acid derivative represented by the_general formula_[1].
Also, the present inventors have_found that a_1-alkylisoindoline-5-boronic acid_derivative represented by_the following general formula [2b]: 
wherein_R4a represents an_alkyl group and R5, R8 and_R9_have the same_meanings_as_mentioned above_is an excellent_intermediate_for producing_a_7-isoindoline-quinolone-carboxylic acid derivative represented by the_following_general formula [1a]: 
wherein R4a, R1, R2,_R5, R6 and A_have_the same meanings as_mentioned above among the compounds_of the general formula [1].
Moreover, it_has been_found that_a 1-alkyl-5-halogenoisoindoline derivative represented by the following general formula [4a]: 
wherein_R4a, R5 and X1 have the_same meanings as mentioned_above, can_be_produced by using_a_4-halogenobenzylamine derivative_as the starting material.
Furthermore, it has been_found that_as the process for producing a_7-bromo-quinolonecarboxylic acid derivative represented_by_the following general formula [3a] which_is a useful intermediate for producing_T-3811: 
wherein R1b represents a_carboxyl-protecting_group;_R7a represents a substituted or_unsubstituted alkyl group; and R2a represents_a substituted or_unsubstituted alkyl, cycloalkyl, aryl or heterocyclic group,_a_process in which a 2,4-dibromo-