N-甲基邻苯二甲酰亚胺的合成新工艺

以 N,N-二甲基甲酰胺作溶剂,四丁基溴化铵作相转移催化剂,碳酸二甲酯作甲基化试剂,由邻苯二甲酰亚胺与氢氧化钾反应先合成钾盐,再经甲基化合成了 N-甲基邻苯二甲酰亚胺。考察了钾盐与碳酸二甲酯的配比、反应时间、溶剂用量、催化剂及催化剂用量等因素对反应收率的影响。较佳合成条件为:n(邻苯二甲酰亚胺钾盐):n(碳酸二甲酯)=1:2,适量溶剂,四丁基溴化铵用量为钾盐的4%(摩尔分数),在120℃反应4 h,反应收率可达70%以上。通过与标准品比对,对产物进行了确认。

NEW PROCESS FOR SYNTHESIS OF N-METHYLPHTHALIMIDE

N-methylphthalimide(NMP)was synthesized from phthalic anhydride(PA)and dimethyl carbonate(DMC)with N,N-dimethylformamide(DMF)as solvent and tetrabutylamonium bromide (TBBA)as phase transfer catalyst(PTC).Phthalic anhydride was transformed to phthalic anhydride potassium(PAP)with potassium hydroxide,and then phthalic anhydride potassium was methylated with dimethyl earbonate.When the molar ratio of n(PAP):n(DMC)was 1:2,the amount of tetra- butylamonium biomide was 4% of n(PAP),reaction temperature was 120℃,reaction time was 4 h, and appropriate quantity solvent,the yield of NMP reached 70%.The final product was identified comparing with standard NMP sample.