PROCESS FOR PREPARING 1,4-DIHYDRO PYRIDIN DERIVATIVES

摘要

The high purity asymmetric 1,4-dihydropyridine deriv. of formula (I) is prepd. by: (a) reacting an aldehyde cpd. of formula R1CHO with a ketocarboxylic acid of formula R4COCH2CO2R2 in an organic solvent, alcohol soln. or water-soluble alcohol solvent in the presence of an amine/dicarboxylic acid (succinic, adipic, malonic or (D,L)-malinic acid) as a catalyst to make a ylidene-beta-ketocarboxylic acid ester of formula (II); and (b) reacting the cpd (II) with an N-amino carboxylic ester of formula (IV). In the formulas, R1 is nitro-cpt. substd. phenyl; R2 and R3 are each H, C1-4 alkyl or alkoxy ethyl; R4 and R5 are each H or C1-4 alkyl. The deriv. (I) has a good blood vessel extension and anti-hypertension activity.