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L'isomérie géométrique d'amidines mono‐substituées de l'acide benzothiazole‐carboxylique‐2. Isomères anti à carboxyle normal, isoméres syn à carboxyle énolisé
Author(s) -
Baudet Pierre,
Rao Dinesh
Publication year - 1970
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.19700530516
Subject(s) - chemistry , tautomer , benzothiazole , keto–enol tautomerism , stereochemistry , enol , imine , condensation , medicinal chemistry , organic chemistry , catalysis , physics , thermodynamics
The condensation of methyl benzothiazole‐2‐iminicarboxylate with α‐amino‐acetic esters gives rise to amidines possessing only one (I) of the two possible tautomeric structures.Both syn and anti isomers have been characterized of the single tautomer. This is the first demonstration of geometrical isomerism around the imine group in amidines. The carboxylic esters and the free acids of the syn fro exist exclusively as the enol, whereas the anti derivatives prefer the carboxyl structure. The existence of these isomers has been confirmed by their IR., UV., and NMR. spectra as well as by the inversion of their configuration and the formation of cyclic derivatives.