1-甲基-3-苯基哌嗪的合成

Synthesis of 1-Methyl-3-phenylpiperazine

研究了1 甲基 3 苯基哌嗪的合成工艺。以N 甲基乙醇胺和环氧苯乙烷为起始原料,在80℃下反应4h,得到N (2 羟乙基) N 甲基 α 羟基 β 苯乙基胺,在0～10℃下将其滴加入氯化亚砜,并在45℃下反应2h,生成N (2 氯乙基) N 甲基 α 氯 β 苯乙基胺,通入过量HCl,得其盐酸盐,在40～45℃下再加入氨水反应3h,经减压蒸馏,重结晶得到目标化合物1 甲基 3 苯基哌嗪,总收率43 9%。目标化合物结构经核磁共振分析验证。

Styrene oxide was treated with N-methylethanolamine at 80 ℃ for 3 h to afford intermediate N-(2-hydroxyethyl)-N-methyl-α-hydroxy-β-phenylethylamine(Ⅰ).Ⅰwas added in a thin stream into thionyl chloride at 0～5 ℃,and the resulting mixture was stirred at 45～55 ℃ for 2 h to afford N-(2-chloroethyl)-N-methyl-α-chloro-β-phenylethylamine(Ⅱ).After blowing excessive hydrogen chloride gas,Ⅱ·HCl was obtained in 75.2% yield(base on N-methylethanolamine).Then Ⅱ·HCl was treated with aqueous ammonia at 40～45 ℃ for 3 h.By distillation under reduced pressure and recrystallization,the title compound 1-methyl-3-phenylpiperazine(Ⅲ) was obtained.Total yield of this procedure reached 43.9%(based on N-methylethanolamine).Ⅲ was identified by NMR.