Process for preparing a dihydropyridine derivative

摘要

Dihydropyridines of formula <IMAGE> where R6 is lower alkyl and R5 is lower alkyl or aryl (lower)alkyl are prepared by a novel process from sodium or potassium salts of 1-substituted-1,6-dihydro-5-hydroxy-3[2H]-pyridones. The dihydropyridines are useful as intermediates for pharmacologically active 1-optionally substituted-3-phenyl or substituted phenylpiperidin-5-ols and esters. Some of the piperidinols and esters are novel; those where the 1-substituent is aryl(lower)alkyl are intermediates, those where the 1-substituent is cycloalkyl(lower)alkyl are analgesics or antidepressants and those in which the 1-position is unsubstituted are anti-secretory agents.