Examination of the structure-activity relationships of 2- (phenylpiperazinoalkoxyphenyl) -thiazolidine-3-carbothioamides and the corresponding carboxamides (1) as new cardiotonic agents was extended by the chemical modification of the phenylpiperazino moiety. The 4-phenylpiperidine (13), 4-phenyltetrahydropyridines (17), and related derivatives were prepared from the chlorides (10) through several intermediates (12, 14, and 16) and tested for cardiotonic activity. Generally, both the 4-phenylpiperidine (13) and 4-phenyltetrahydropyridine (17) derivatives exhibited potent positive inotropic activity comparable to that of 1. The N-phenylpiperidines (9) and amide derivatives (22, 25, and 28) exhibited no significant positive inotropy. This is also the case for the phenylpropylamines (29) and the ethylenediamines (30), which are pseudo-ring analogues of 1 with respect to the piperazine moiety. The activity of the homopiperazine derivative (23) was approximately one-thirtieth of that of the corresponding piperazine derivative (1). Thus, the presence of the six-membered, basic azacycloalkane ring (piperidine or piperazine) with a 4-phenyl group at the end of the alkoxy side chain appears to be essential for the appearance of potent positive inotropic activity in this series of compounds.
通过对苯基
哌嗪分子进行
化学修饰,扩展了作为新型强心剂的 2-(苯基
哌嗪烷氧基苯基)-
噻唑烷-3-
硫代酰胺和相应羧酰胺(1)的结构-活性关系研究。从
氯化物(10)通过几个中间体(12、14 和 16)制备出了
4-苯基哌啶(13)、4-苯基四氢
吡啶(17)和相关衍
生物,并进行了强心活性测试。一般来说,
4-苯基哌啶(13)和 4-苯基四氢
吡啶(17)衍
生物都表现出与 1 相似的强效正性肌力活性,而
N-苯基哌啶(9)和酰胺衍
生物(22、25 和 28)则没有表现出明显的正性肌力活性。苯基
丙胺(29)和
乙二胺(30)的情况也是如此,它们是 1 的
哌嗪分子的假环类似物。均
哌嗪衍
生物(23)的活性约为相应
哌嗪衍
生物(1)的三十分之一。因此,在这一系列化合物中,烷氧基侧链末端含有 4-苯基基团的六元碱性氮杂环烷环(
哌啶或
哌嗪)似乎是产生强效正性肌力活性的关键。