(2-bromo-3-aryl)propanoates were formed. Their cyclization with thiourea produced 5-(R-benzyl)-2-imino-4-thiazolidinones, which yielded 3-aryl-2-mercaptopropanoic acids by alkaline hydrolysis. Second, direct Meerwein arylation of acrylates in the presence of S-nucleophile (NaSH) allowed isolation of 3-phenyl-2-mercaptopropanoic acid in 8% yield. Such acids were used for cyclization with cyanoguanidine and phenyl isothiocyanate
摘要 开发了两条制备2-巯基-3-芳基
丙酸的合成途径。首先,通过
芳烃重
氮溴化物与
丙烯酸酯在 CuBr 存在下的反应,形成(2-
溴-3-芳基)
丙酸烷基
酯。它们与
硫脲的环化产生 5-(R-
苄基)-2-亚
氨基-4-
噻唑烷
酮,通过碱
水解产生 3-芳基-2-巯基
丙酸。其次,在 S-亲核试剂 (NaSH) 存在下,
丙烯酸酯的直接 Meerwein 芳基化允许以 8% 的产率分离 3-
苯基-2-巯基
丙酸。这些酸用于与
氰基
胍和异
硫氰酸苯酯环化,产生 1-[5-(R-
苄基)-4-
氧代-1,3-
噻唑烷-2-亚基]
胍和新的 5-(R-
苄基)-3-
苯基-2-thioxo-1,3-thiazolidin-4-one (rhodanine) 衍
生物相应。图形概要