A novel method of synthesizing 2-disubstituted-amino-4-arylthiazol-5-ylalkanoic acids (3) was studied. Dehydration of S-(α-benzoyl-β-ethoxycarbonyl) ethyl 1-piperidinethiocarbonate (5a) in the presence of aqueous perchloric acid-acetic anhydride yielded 4-ethoxycarbonyl-methyl-5-phenyl-2-piperidino-1, 3-oxathiolium perchlorate (1a). Nucleophilic reaction of ammonia with 1a afforded 5-ethoxycarbonylmethyl-4-phenyl-2-piperidinothiazole (2a). Acid-catalyzed hydrolysis of 2a gave 3a as a hydrochloride. The acids (3) were also synthesized by the classical Hantzsch method. These alkanoic acids were evaluated as antiinflammatory agents on carrageenin-induced abscess in rat.
研究了一种合成 2-二取代-
氨基-4-芳基
噻唑-5-基烷酸(3)的新方法。S-(α-benzoyl-β-ethoxycarbonyl) 1-
哌啶硫代
碳酸乙酯(5a)在
高氯酸-
乙酸酐水溶液存在下脱
水生成 4-乙氧羰基-甲基-5-苯基-2-
哌啶基-1,3-氧
硫杂
环戊烷高氯酸盐(1a)。
氨与 1a 发生亲核反应,得到 5-乙氧羰基甲基-4-苯基-2-
哌啶噻唑(2a)。2a 在酸催化下
水解,得到盐酸盐 3a。酸 (3) 也是通过经典的 Hantzsch 方法合成的。这些烷酸作为抗炎剂对角叉菜胶诱发的大鼠脓肿进行了评估。