2,2-二甲基-2,3-二氢(口白)啶的合成

Synthesis of 2,2-Dimethyl-2,3-Dihydroperimidine

以1,8-二氨基萘和丙酮为原料,无水乙醇为溶剂,对甲苯磺酸催化下合成了2,2-二甲基-2,3-二氢（口白）啶。适宜的反应条件为:原料摩尔比（1,8-二氨基萘/丙酮）1:1.5,对甲苯磺酸用量 1％（以1,8-二氨基萘计）,反应时间1.0小时,反应温度为55～60℃,收率为84.0％。UV、IR、HMR符合结构特征。滤液循环套用后,产品收率由84.0％提高到92.9％;套用4次时,产品质量基本稳定。

1,8-naphthalenediamine was condensed with acetone in the presence of p-toluenesulfonic acid to form 2,2-dimethyl-2,3-dihydroperimidine in 84.0% yield. Some factors influencing on the reaction were discussed. The reaction conditions were recommended that molar ratio of 1,8-naphthalene diamine and acetone was 1:1.5, amount of p-toluenesulfonic acid was 1% of 1,8-naphthalenediamine, the reaction mixture was reacted at 55-60℃ for 1h. A simple synthetic process and lower costs of raw materials was achieved. The extent of corrosion of equipment and the environment pollution reduced, and the filtrate may be recycled, the yield of the product raised from 84.0% to 92.9%.