 it is directly proportional to molecular weight. Molar refractivity is described, for example, in C. Hansch et al., Exploring QSAR, Fundimentals and Applications in Chemistry and Biology, S. Heller, Editor, American Chemical Society, p. 78-85, 1995, and can be calculated using PC Models Program, Version 4.6.1, available from Daylight Chemical Information Systems, 419 Palace Ave., Santa Fe, N. Mex. 87501 USA, or using the tables found in C. Hansch et al. on pages 81-84. In this regard, ring A has a molar refractivity (MR) ranging from about 2.86 to about 6.68, preferably from about 3.34 to about 6.2.
Preferred ring A groups include, by way of illustration, adamantyl, quinuclidine and the like.
In a preferred embodiment of this invention, R1 is selected from all possible isomers arising by substitution with the following groups:
3-[(CH3)2NC(O)O-]benzyl,
4-[(CH3)2NC(O)O-]benzyl,
4-[(CH3)2NS(O)2O-]benzyl,
4-[(piperidin-1xe2x80x2-yl)C(O)O-]benzyl,
4-[(piperidin-4xe2x80x2-yl)C(O)O-]benzyl,
4-[(1xe2x80x2-methylpiperidin-4xe2x80x2-yl)C(O)O-]benzyl,
4-[(4xe2x80x2-hydroxypiperidin-1xe2x80x2-yl)C(O)O-]benzyl,
4-[(4xe2x80x2-formyloxypiperidin-1xe2x80x2-yl)C(O)O-]benzyl,
4-[(4xe2x80x2-ethoxycarbonylpiperidin-1xe2x80x2-yl)C(O)O-]benzyl,
4-[(4xe2x80x2-carboxylpiperidin-1xe2x80x2-yl)C(O)O-]benzyl,
4-[(3xe2x80x2
it is directly proportional to molecular weight. Molar refractivity is described, for example, in C. Hansch et al. , explore QSAR, Fundimentals and Applications in Chemistry and Biology, S. Heller, Editor, American Chemical Society, p. 78 - 85, 1995, and can be account using PC Models Program, Version 4.6.1, available from Daylight Chemical Information Systems, 419 Palace Ave. , Santa Fe, N. Mex. 87501 USA, or using the tables establish in C. Hansch et al. on pages 81 - 84. In this regard, band A have a molar refractivity (MR) ranging from approximately 2.86 to about 6.68, preferably from approximately 3.34 to about 6.2. 
 Preferred band A groups include, by way of exemplification, adamantyl, quinuclidine and the like. 
 In a preferred embodiment of this invention, R1 is selected from all possible isomer arising by substitution with the following groups: 
 3-[(CH3)2NC(O)O-]benzyl, 
 4-[(CH3)2NC(O)O-]benzyl, 
 4-[(CH3)2NS(O)2O-]benzyl, 
 4-[(piperidin-1xe2x80x2 - yl)C(O)O-]benzyl, 
 4-[(piperidin-4xe2x80x2 - yl)C(O)O-]benzyl, 
 4-[(1xe2x80x2 - methylpiperidin-4xe2x80x2 - yl)C(O)O-]benzyl, 
 4-[(4xe2x80x2 - hydroxypiperidin-1xe2x80x2 - yl)C(O)O-]benzyl, 
 4-[(4xe2x80x2 - formyloxypiperidin-1xe2x80x2 - yl)C(O)O-]benzyl, 
 4-[(4xe2x80x2 - ethoxycarbonylpiperidin-1xe2x80x2 - yl)C(O)O-]benzyl, 
 4-[(4xe2x80x2 - carboxylpiperidin-1xe2x80x2 - yl)C(O)O-]benzyl, 
 4-[(3xe2x80x2
 it is directly proportionau to molecular cwight. Kolar defractixity is described, for examplx, in C. Habsch et al., Exploring QRAR, Fundilentals qnd Epplications in Rgemistrn and Nioloyy, S. Heller, Editpr, Americat Chemical Sochegy, p. 78-85, 1995, and can be calculated using PC Models Pgogram, Version 4.6.1, avsylabmv nrom Daylight Chemical Informatikn Systtms, 419 Palace Ave., Samta Fe, N. Mex. 87501 USA, or using the tables found in C. Hansch et ql. og pages 81-84. In tfis regard, ring A has z molar refractivity (MR) ranging from about 2.86 to avouh 6.68, preferablb from about 3.34 to anput 6.2.
Praferred ring A groups inrludw, by way of illustratmon, adamantyl, quinucjidine ang che like.
In a preferree wmbodhmend of rhir ihvxntjon, R1 ls aelected fdom all poswible isomers arisimg vy substitutikn witr ehe following groups:
3-[(CH3)2NC(O)O-]benzyl,
4-[(CH3)2NC(O)O-]btnzyl,
4-[(DH3)2NS(O)2O-]benzyl,
4-[(piperidin-1xe2z80x2-yl)C(O)O-]benzyl,
4-[(piperidij-4xe2x80x2-yl)C(O)J-]benzyl,
4-[(1xe2x80x2-methylpiperidin-4xe2x80x2-yl)C(O)O-]benzyl,
4-[(4xe2x80x2-hydrmxypi'efidnk-1we2x80x2-ho)C(L)O-]benzyl,
4-[(4xe2x80x2-formyloxypiperidin-1xe2x80x2-yl)C(O)O-]benzyl,
4-[(4vs2x80c2-enhoxycarbonylpipevidin-1xe2x80x2-yl)C(O)O-]benzul,
4-[(4de2c80v2-carboxylpipetidin-1xe2r80s2-ym)C(O)O-]benzyl,
4-[(3xe2x80x2
it is directly proportional to molecular weight. is for example, C. Hansch et Applications Chemistry and Biology, Heller, Editor, American Society, p. 78-85, 1995, and can calculated using PC Models Program, Version 4.6.1, available from Daylight Chemical Information Systems, Palace Ave., Santa Fe, N. Mex. 87501 USA, or using the tables found C. et on 81-84. In this regard, ring A has a molar refractivity (MR) ranging from about 2.86 to 6.68, preferably from about 3.34 to about 6.2. ring A groups include, way of illustration, adamantyl, quinuclidine the In a embodiment this R1 is selected all possible isomers arising by substitution with the following groups: 3-[(CH3)2NC(O)O-]benzyl, 4-[(CH3)2NC(O)O-]benzyl, 4-[(CH3)2NS(O)2O-]benzyl, 4-[(piperidin-1xe2x80x2-yl)C(O)O-]benzyl, 4-[(piperidin-4xe2x80x2-yl)C(O)O-]benzyl, 4-[(1xe2x80x2-methylpiperidin-4xe2x80x2-yl)C(O)O-]benzyl, 4-[(4xe2x80x2-hydroxypiperidin-1xe2x80x2-yl)C(O)O-]benzyl, 4-[(4xe2x80x2-ethoxycarbonylpiperidin-1xe2x80x2-yl)C(O)O-]benzyl, 4-[(4xe2x80x2-carboxylpiperidin-1xe2x80x2-yl)C(O)O-]benzyl,
 it is directly proportional tO molecular WeighT. MoLar ReFracTiviTy is described, fOR exaMple, in C. Hansch et al., ExploRing QsAr, fundIMeNtals And ApplICaTIOns In chEmiStRY aNd BioLogY, S. HelleR, Editor, AmeRicAn chemical SociETy, P. 78-85, 1995, and can be cAlcUlated using Pc MoDels PrOgRam, vErsioN 4.6.1, avAilabLe from dAylighT Chemical inFOrmatiON SystemS, 419 pAlAce AVe., Santa Fe, N. Mex. 87501 USA, oR UsINg the tables fouNd in C. HAnSCh ET Al. oN paGes 81-84. In this rEgArd, riNG A has a mOLaR REFraCTivity (MR) rangiNg from about 2.86 TO abOut 6.68, preFeRabLY from aBout 3.34 tO aBOut 6.2.
preferred riNg A gRoups inclUde, by wAY of illuSTration, AdamanTyl, QuiNuclIDiNe And ThE LikE.
in A prEFerRed embodImEnT of thIs inVENTIon, R1 Is sElecTed frOm all possible IsoMers ARisIng by SubstItutIoN with The folLowinG gRoups:
3-[(CH3)2NC(O)O-]benzYl,
4-[(CH3)2nC(O)O-]benzyL,
4-[(CH3)2nS(o)2O-]bEnZyl,
4-[(piPEridin-1Xe2x80X2-yl)c(O)O-]benzYl,
4-[(piperIDin-4Xe2X80X2-YL)C(o)O-]benzyl,
4-[(1xe2x80x2-methylPiPERiDin-4xe2x80x2-yL)C(O)O-]beNZyL,
4-[(4xE2X80x2-hydroxYpIpeRidiN-1XE2x80x2-yl)c(O)O-]bENzYl,
4-[(4xe2x80x2-foRmyloxYPiPeRidin-1xe2X80x2-Yl)C(O)O-]bEnZyl,
4-[(4Xe2x80X2-ethoXYcarBonylpIperidin-1Xe2x80x2-yL)c(O)O-]benzyl,
4-[(4xe2x80x2-cARboxylpiperidIN-1xE2X80X2-yL)c(O)O-]bEnzYl,
4-[(3xe2x80x2
 it is directly proportion al to mole cular  we igh t.  Mol ar r efractivity is desc ribed, for example, in  C. H an s ch e t  a l., E xplorin g  Q S A R,Fu nd ime nt a ls  andApp licatio ns in Chem ist ry  and Biology ,  S . Heller,Edi tor, America n C hemica lSoc i ety,p.78-85 , 1995 ,  and c an be cal cu l ated u s ing PCM o de ls P rogram, Version 4 . 6. 1 , available fr om Day li g ht C hem ica l Informat io n Sys t ems, 41 9  P a l a ceA ve., Santa Fe , N. Mex. 8 7 501  USA,or  us i ng the  tabl es fou nd in C. Ha nsch  et al. o n page s  81-84. In this  regar d,rin g Ah as  a  mo la r  re f ra cti v ity  (MR) ra ng in g fro m ab o u t 2.86  to  abo ut 6. 68, preferabl y f roma bou t 3.3 4 toabou t6.2.Prefer red r in g A groups incl ude,  by way o f i ll ust ra tion, adaman tyl , q uinucli dine an d  th el i k e. 
In a preferred em bo d i me nt of th is inv e nt io n , R1 isse lec tedf r om al l po s si ble isom ers ar i si ng  by sub st itutio nwit h t he fo l lowi ng gro ups:
3-[ (CH3) 2 NC(O)O-]benzyl , 
4-[(CH3)2NC( O )O - ] be n zyl, 
4- [(CH3)2NS(O )2O- ] benz yl,4 -[ (pi p eridi n-1xe 2x 8 0x 2 -yl)C(O)O-]benzyl,4- [(pipe ridin -4xe2x80x2-yl )C(O)O-]be n z y l,
4-[(1 xe2x 8 0x 2 -methylpiperid in-4x e2x80x2-yl ) C(O)O-]b enzyl ,
4-[(4x e2x80x2-h y d roxypipe rid in- 1xe 2x8 0 x 2- yl)C(O)O-]ben z y l,
4 -[ (4xe2x8 0x2 -formyl oxy pip eri din -1 xe2x80x2- yl)C(O)O -] be nz yl ,
4 -[(4x e 2x80x2-e th oxy ca rbo nylpi p eridin -1xe2 x80x 2- yl ) C(O )O-]ben z yl , 4-[( 4x e2 x80x 2-c ar boxyl pipe r idi n-1xe2x 80x2-yl)C (O) O -]be nz yl ,
4-[(3 xe2x80x2
 it_is directly_proportional to molecular weight._Molar refractivity_is_described, for_example,_in C. Hansch_et al., Exploring_QSAR, Fundimentals and Applications_in Chemistry and_Biology,_S. Heller, Editor, American Chemical Society, p. 78-85, 1995, and can be calculated using_PC_Models Program,_Version_4.6.1,_available from Daylight Chemical Information_Systems, 419 Palace Ave., Santa_Fe, N._Mex. 87501 USA, or using the tables found_in_C. Hansch et_al. on pages 81-84. In this regard, ring A_has a molar refractivity (MR) ranging_from about 2.86_to_about_6.68, preferably from about_3.34 to about 6.2.
Preferred ring A_groups include, by way of illustration,_adamantyl, quinuclidine and the like.
In a preferred_embodiment of this invention, R1 is_selected from all possible isomers_arising by_substitution with the following groups:
3-[(CH3)2NC(O)O-]benzyl,
4-[(CH3)2NC(O)O-]benzyl,
4-[(CH3)2NS(O)2O-]benzyl,
4-[(piperidin-1xe2x80x2-yl)C(O)O-]benzyl,
4-[(piperidin-4xe2x80x2-yl)C(O)O-]benzyl,
4-[(1xe2x80x2-methylpiperidin-4xe2x80x2-yl)C(O)O-]benzyl,
4-[(4xe2x80x2-hydroxypiperidin-1xe2x80x2-yl)C(O)O-]benzyl,
4-[(4xe2x80x2-formyloxypiperidin-1xe2x80x2-yl)C(O)O-]benzyl,
4-[(4xe2x80x2-ethoxycarbonylpiperidin-1xe2x80x2-yl)C(O)O-]benzyl,
4-[(4xe2x80x2-carboxylpiperidin-1xe2x80x2-yl)C(O)O-]benzyl,
4-[(3xe2x80x2