CRYSTAL-STRUCTURE ANALYSIS OF HYL-3,5-N-(DIMETHYLCARBAMOYL)-1,4-DIHYDROPYRIDINES [R=2-NITRO (1), 4-METHOXY (2) AND 3,4-DICHLORO (3)]

The crystallographic characterization of the following three calcium c hannel antagonists is reported here: 2,6-dimethyl-3,5-dicarbamoyl-4-[2 -nitro] 1,4-dihydropyridine (1), -3,5-dicarbamoyl-4-[4-methoxy]-1,4-di hydropyridine (2) and 2,6-dimethyl-3,5-dicarbamoyl-4-[3 ,4-dichloro]-1 ,4-dihydropyridine (3). The dihydropyridine rings are in shallow boat conformation in all the three compounds. The carbamoyl groups at C3 an d C5 are oriented anticlinal in 1 and 2; but in 3, they are anticlinal and synperiplanar, respectively. It is possible that intra and interm olecular interactions may be influencing the positioning and orientati on of the aryl substituents and the conformation of the novel C3 and C 5 carbamoyl group. In addition, it is seen that participation of the m olecules of crystallization has significantly changed the hydrogen bon ding network.