Reactions of 3-methyl-2,3-dihydrobenzothiazole-2-thione (1) and 3-methyl-2-(methylthio)benzothiazoliumiodide with Grignard reagents gave 2,2-disubstituted 3-methyl-2,3-dihydrobenzothiazole (2) as a major product as well as 2,2′-disubstituted 3,3′-dimethyl-2,2′,3,3′-tetrahydrobi(2-benzothiazolyl) (3). Reactions of 1 with organolithiums gave 2 as a major product. The results demonstrate that the formation of 3 is due to the presence of transition metals as an impurity in magnesium.
3-甲基-2,3-二氢苯
噻唑-2-
硫酮(1)和3-甲基-2-(甲基
硫)苯
噻唑铵碘化物与
格氏试剂反应,主要生成2,2-二取代的3-甲基-2,3-二氢苯
噻唑(2),同时也生成2,2′-二取代的3,3′-二甲基-2,2′,3,3′-四氢双(2-苯
噻唑基) (3)。1与
有机锂化合物的反应也以2为主要产物。结果表明,3的形成是由于
镁中存在过渡
金属杂质。