Various 2-mercapto-4-substituted-5-imidazolecarboxylates (5) were synthesized by the reaction of C-acylamino acid methyl esters (4) with potassium thiocyanate. Hydrolysis followed by decarboxylation of the imidazole carboxylates (5) gave 2-mercapto-4-substituted imidazoles (8) in good yields. Furthermore, the imidazoles (8) were also directly obtained by the reaction of aminoketones (9) with potassium thiocyanate. These compounds (8) exhibited antiinflammatory activities against carrageenan-induced rat paw edema. Among the compounds tested, 2-mercapto-4-(3-thienyl) imidazole (8r) showed the best therapeutic index value, giving a value comparable to that of mefenamic acid.
通过 C-酰基
氨基甲酯(4)与
硫氰酸钾的反应,合成了各种 2-巯基-4-取代的-5-
咪唑羧酸盐(5)。
咪唑羧酸盐(5)
水解后再脱羧,可得到 2-巯基-4-取代的
咪唑(8),收率很高。此外,
氨基酮(9)与
硫氰酸钾反应也可直接得到
咪唑(8)。这些化合物(8)对
卡拉胶诱导的大鼠爪
水肿具有抗炎活性。在测试的化合物中,2-巯基-4-(3-
噻吩基)
咪唑(8r)的治疗指数值最高,与
甲灭酸的治疗指数值相当。