Methyl 5-substituted oxazole-4-carboxylates were synthesized by the reaction of methyl α-isocyanoacetate with acylating reagents in the presence of bases. The oxazole methyl esters were converted into the carboxylic acids and the carboxamides. Then, N-alkyl-oxazole-4-carboxamides were prepared through the oxazole-4-carboxylic acid chloride. Furthermore, 2-substituted oxazoles were synthesized by cyclization of N-acyl-α-benzoylglycine methyl esters. which were obtained by acylation of α-benzoylglycine methyl ester followed by ammonolysis of the resulting oxazole methyl esters. These oxazole compounds were evaluated for inhibitory activity on blood platelet aggregation in vitro and ex vivo. Some of these compounds showed the inhibitory activity comparable to that of aspirin. Of these, 5-(3, 4, 5-trimethoxyphenyl) oxazole-4-carboxamide was the most active compound in the ex vivo test.
α-
异氰基乙酸甲酯在碱存在下与酰化试剂反应,合成了 5-取代的噁
唑-4-羧酸甲酯。
噁唑甲酯被转化成
羧酸和羧酰胺。然后,通过
噁唑-4-羧酰
氯制备出 N-烷基
噁唑-4-羧酰胺。此外,还通过 N-酰基-α-苯甲酰基甘
氨酸甲酯的环化合成了 2-取代的
噁唑,这些
噁唑甲酯是通过α-苯甲酰基甘
氨酸甲酯的酰化,然后对生成的
噁唑甲酯进行
氨解而得到的。对这些
噁唑化合物进行了体外和体内血小板聚集抑制活性评估。其中一些化合物的抑制活性与
阿司匹林相当。其中,5-(3, 4, 5-三
甲氧基苯基)
恶唑-4-甲酰胺是体内外试验中活性最强的化合物。