Nisoldipine: C~20~H~24~N~2~O~6~. Mw: 388.41. (1) 3,5-Pyridinedicarboxylic acid, 1,4-dihydro-2,6-dimethyl-4-(2-nitrophenyl)-, methyl 2-methylpropyl ester, (±)-; (2)(±)-Isobutyl methyl 1,4-dihydro-2,6-dimethyl-4-(o-nitrophenyl)-3,5-pyridinedicarboxylate. CAS-63675-72-9 (1981).