Stereochemical studies on medicinal agents. 21. Investigation of the role of conformational factors in the action of diphenylpropylamines. Synthesis and analgetic potency of 5-methylmethadone diastereomers
作者:James G. Henkel、Eric P. Berg、Philip S. Portoghese
DOI:10.1021/jm00233a011
日期:1976.11
solution conformation of each isomer was investigated through pKa and NMR studies. The data indicate that 3a-HCl exists exclusively in an internally hydrogen-bonded conformation while the erythro isomer 3b-HCl is present as a mixture of conformations. The erythro racemate 3b was found to possess 5.4 times the analgetic potency of (+/-)-methadone in contrast to the threo racemate 3a which was inactive
进行了外消旋的苏-和赤--5-甲基美沙酮(分别为3a和3b)的合成,并通过pKa和NMR研究了每种异构体的溶液构象。数据表明3a-HCl仅以内部氢键构象存在,而赤型异构体3b-HCl以构象混合物形式存在。发现赤型外消旋体3b具有(+/-)-美沙酮的镇痛效力的5.4倍,而苏式消旋体3a是无活性的并且没有拮抗剂活性。非活性外消旋体3a包含5S,6R立体异构体,该结构结合了美沙酮和异美沙酮的更具活性的对映异构体中的构型,提示手性中心不能表现为独立的单元,构象因素在控制立体选择性中起着重要作用。当与早期报道一起分析时,这些结果表明,二苯丙胺镇痛药的一种药效学构型具有Ph2CCOEt和+ NHMe2基团的类似反平面的结构。