NEW MATERIAL:The compound of formula I (R1 is H or aryl; R2 and R3 are aryl; R4WR6 are lower alkyl; Z is alkylene; m and n are 0 or 1).

EXAMPLE: 1,4-Dihydro-2,6-dimethyl-4-(3-nitrophenyl)-3,5-pyridinedicarboxylic acid 2-(4-diphenylmethylpiperidino)ethyl methyl ester.

USE: Drug. It has low toxicity and strong and long-acting hypotensive, peripheral vasodilating, coronary vasodilating, and cerebral vasodilating activities compared with known nifedipine, nicardipine, etc., and is useful as a preventive and remedy for circulatory diseases, e.g. ischemic cardiopathy such as hypertension, stenocardia, etc., or cerebral or peripheral circulation disorder such as cerebral infarction, transient ischemic attack, etc.

PREPARATION: The compound of formula I can be produced, e.g. by reacting the compound of formula II with the compound of furmula III and the compound of formula IV in a solvent at 20W160°C for 0.5W1.5hr.