NEW MATERIAL:A compound shown by formula I {R1 is NO2, CN or trihalo (lower) alkyl; R2 is Ra-lower alkyl; Ra is [N-lower alkyl-N-haloar (lower) alkyl]amino; R3 and R4 are lower alkyl; R5 is CHO or di (lower) alkoxy-methyl} or a salt thereof.

EXAMPLE: 5-Ethoxycarbonyl-6-diethoxymethyl-2-methyl-4-(3-nitrophenyl)-1,4-dihy- dropyridine-3-carboxylic acid 2-[N-(4-chlorobenzyl)-N-methylamino]ethyl ester.

USE: A blood vasodilator and an intermediate thereof.

PREPARATION: A compound shown by formula I-A [R2' is halo (lower) alkyl] is reacted with a compound shown by formula Ra-H or a salt thereof to give a compound shown by containing I-1, which is hydrolyzed to give a compound shown by formula I-2. These compounds are useful an intermediate for a com pound shown by formula II (R5' is CN or CH2OH) excellent especially as the above-mentioned drug.