Optically active isomers of N-methyl-2- (2- (2- (4-phenylpiperazino) ethoxy) phenyl) thiazolidine-3-carboxamides ((+) -2 and (-) -2) have been synthesized and tested for positive inotropic activity. The racemic thiocarboxamide ((±) -3) was resolved into the enantiomers ((+) -3 and (-) -3) via the L-and D-N- (2-naphthylsulfonyl) prolyl derivatives ((+) -4 and (-) -4). Conversion of the thiocarboxamides ((+) -3 and (-) -3) to the carboxamides ((+) -2 and (-) -2) was smoothly effected by treatment with the glycidic ester (7). The absolute stereochemistry of (-) -3 was determined to be 2S by X-ray crystallographic analysis. Hence, the absolute configuration of the carboxamide ((-) -2) is 2S. On i.v. administration to anesthetized dogs, the enantiomers of 2 showed only a threefold difference in positive inotropic activity, with the levo isomer ((-) -2) being the more active. In the isolated cat heart muscle, the enantiomers were nearly equipotent to each other. Thus, no significant difference between the positive inotropic activities of the optical isomers of 2 was observed.
我们合成了 N-
甲基-2-(2-(2-(4-
苯基
哌嗪)乙
氧基)
苯基)
噻唑烷-3-甲
酰胺((+) -2和(-) -2)的光学活性异构体,并对其正性肌力活性进行了测试。外消旋
硫代甲
酰胺((±) -3)通过 L 和 D-N-(2-
萘磺酰基)脯
氨酸衍
生物((+) -4和(-) -4)分解成对映体((+) -3和(-) -3)。
硫代羧
酰胺((+) -3和(-) -3)通过
缩水甘油酯(7)的处理顺利转化为羧
酰胺((+) -2和(-) -2)。通过 X 射线晶体分析,确定 (-) -3 的绝对立体
化学结构为 2S。因此,羧
酰胺((-) -2)的绝对构型为 2S。给麻醉犬静脉注射 2 的对映体后,其正性肌力活性仅相差三倍,其中左旋异构体((-) -2)的活性更高。在离体猫心肌中,对映体之间几乎等效。因此,2 的光学异构体之间的正性肌力活性没有明显差异。