METHOD OF SYNTHESIS OF PURE ENANTIOMERS OF 1,4-DIHYDROPYRIDINES, PURE ENANTIOMERS OF 1,4-DIHYDROPYRIDINES AND ISOTHIOUREIDES Russian patent published in 1996 - IPC

FIELD: organic chemistry. SUBSTANCE: products: pure enantiomers of 1,4-dihydropyridines of the formula (I) where A - hydrogen, -SC-=N-R₂₁)-NR₂₂R₂₃, -SH, SR₂; R₃ - free or esterified carboxyl-group; R₄ - unsubstituted of substituted phenyl, naphthyl, 5- or 6-membered heterocyclic ring containing heteroatom taken from N, S or O; R₅ - free or esterified carboxyl-group; R₂ - phenyl, alkenyl, alkynyl, carboxyl-group; R₆ - C₁-C₆-alkyl, haloidalkyl, CHO, -C≡N; n = 1-4; R₂₁,R₂₂,R₂₃ - hydrogen, C₁-C₄-alkyl, phenylalkyl, acyl. Reagent 1: compound of the formula (II) where R₃-R₆,R₂₁,R₂₂,R₂₃ and n have values indicated above. Reagent 2: chiral acid HB^*R₂₃. Reaction conditions: synthesized isothiouronium diastereoisomeric salts were separated and converted to other isothiouronium salts using achiral acids. Synthesized compounds were used in medicine as antihypertensive agents. ???EFFECT: improved method of synthesis. 10 cl