Methylated Analogues of Methyl (<i>R</i>)-4-(3,4-Dichlorophenylacetyl)- 3-(pyrrolidin-1-ylmethyl)piperazine-1-carboxylate (GR-89,696) as Highly Potent κ-Receptor Agonists: Stereoselective Synthesis, Opioid-Receptor Affinity, Receptor Selectivity, and Functional Studies
作者:Stella Soukara、Christoph A. Maier、Ursula Predoiu、Andreas Ehret、Rolf Jackisch、Bernhard Wünsch
DOI:10.1021/jm0108395
日期:2001.8.1
Analogues of the kappa-receptor agonist methyl (R)-4-(3,4-dichlorophenylacetyl)-3-(pyrrolidin-1-ylmethyl)piperazine-1-carboxylate (GR-89,696, 6) bearing an additional methyl substituent in the side chain are synthesized and evaluated for their kappa-receptor affinity and selectivity. A key step in the synthesis is the stereoselective reductive amination of the ketones 9, 18, and 19 with pyrrolidine
(R)-4-(3,4-二氯苯基乙酰基)-3-(吡咯烷-1-基甲基)哌嗪-1-羧酸甲酯(GR-89,696,6)的κ受体激动剂的类似物,在其中合成侧链并评估其κ受体亲和力和选择性。合成中的关键步骤是用吡咯烷和NaBH(3)CN对酮9、18和19进行立体选择性还原胺化,仅在路易斯酸Ti(OiPr)(4)存在下才能成功。BOC取代的酮9以70:30的比例提供10的异种和类非对映异构体,而丁基和苯基取代的酮18和19的还原胺化过程中的非对映选择性则提高到85:15(丁基衍生物),并且> 95:<5(苯基衍生物),有利于不同的非对映异构体。在使用放射性配体[(3)H] U-69,593的受体结合研究中,(S,S)配置的氨基甲酸甲酯(S,S)-14显示出最高的κ受体亲和力(K(i)= 0.31 nM)这个系列,甚至超过了领先的Kappa激动剂6(GR-89,696)。丙酰胺(S,S)-13(K(i)=