Some 3-(aliphatic and aromatic) acylaminomethyl derivatives of 6-( chloro, fluoro, methoxy, methylthio, phenoxy and phenylthio )-2-(phenyl, 4-t-butylphenyl, 4-cyclohexylphenyl, β- naphthyl and styryl ) imidazo [1,2-b] pyridazines have been prepared and tested for binding to central benzodiazepine receptors present in rat brain membrane, and to peripheral-type (mitochondrial) benzodiazepine receptors present in rat kidney membrane. Some of these compounds which contained 2-(4-t-butylphenyl, 4-cyclohexylphenyl and styryl ) substituents bound strongly and selectively to peripheral-type benzodiazepine receptors. For example, 2-(4′-t-butylphenyl)-6-chloro-2-(4″-fluorobenzamidomethyl) imidazo [1,2-b] pyridazine in tests for the displacement of [3H]diazepam from both peripheral-type and central benzodiazepine receptors gave IC50 <1.0 nM and 9% displacement at 1000 nM , respectively. Steric effects appeared to be more restrictive in the interaction of these ligands with central benzodiazepine receptors rather than with peripheral-type benzodiazepine receptors; X-ray structure analyses of two typical compounds are reported.
一些6-(氯、氟、甲氧基、甲硫氧基、苯氧基和苯硫氧基)基-2-(苯基、4-叔丁基苯基、4-环己基苯基、β-萘基和芳基)咪唑[1,2-b]吡啶嗪的3-(脂肪和芳香族)酰胺甲基衍生物已制备并测试其与大鼠脑膜中存在的中枢苯二氮卓类受体以及大鼠肾膜中存在的外周型(线粒体)苯二氮卓类受体的结合。其中一些含有2-(4-叔丁基苯基、4-环己基苯基和芳基)取代基的化合物与外周型苯二氮卓类受体结合强烈且具有选择性。例如,在对2-(4'-叔丁基苯基)-6-氯-2-(4''-氟苯甲酰胺基甲基)咪唑[1,2-b]吡啶嗪进行[3H]地西泮从外周型和中枢苯二氮卓类受体的位点上的置换测试时,其IC50 <1.0 nM,分别在1000 nM时分别表现为9%的置换。立体效应似乎在这些配体与中枢苯二氮卓类受体的相互作用中更具限制性,而不是与外周型苯二氮卓类受体的相互作用;报道了两种典型化合物的X射线结构分析结果。