2-氨基-5-甲基噻唑的合成

由丙醛、乙酐和硫脲为主要原料,经多步化学反应合成２ 氨基 ５ 甲基噻唑。丙醛与乙酐在乙酸钠催化作用下反应生成烯醇乙酸酯,烯醇乙酸酯加溴、醇解得α 溴缩醛,收率为４１－５％ ,再水解制得α 溴丙醛,收率为７１－４％ 。α 溴丙醛与硫脲缩合而得２ 氨基 ５ 甲基噻唑,收率为６１－２％ 。该方法相对产率高,反应容易操作,为合成２ 氨基 ５ 甲基噻唑和α 溴丙醛提供一个较好的方法,适合批量生产。

Synthesis of 5-Methyl-2-thiazolamine

Methyl 2 thiazolamine was obtained through multistep reactions with propionaldehyde, acetic anhydride and thiourea. Propionaldehyde reacted with acetic anhydride in the presence of sodium acetate to give enol acetate which added bromine rapidly,and 2 bromo 1, 1 dimethoxypropane was obtained through alcoholysis. The yield was 41 5%. After hydrolysis,α bromopropionaldehyde was prepared. The yield was 71 4%. α Bromopropionaldehyde condensed with thiourea to give 5 methyl 2 thiazolamine. The yield was 61 2%. The yield was higher and the reaction was easy to control . This method provided a better way to get 5 methyl 2 thiazolamine and α bromopropionaldehyde and was applicable to the batch production.