N-甲基四氢咔唑酮的绿色合成工艺初探

Study on a Novel Green Synthetic Technology for N-Methy-1,2,3,4-Tetrahydrocarbazole-4-one

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,由四氢咔唑酮与氢氧化钾反应先合成钾盐,再经甲基化合成了N-甲基四氢咔唑酮。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。较佳合成条件为碳酸二甲酯∶四氢咔唑酮钾盐=2.5∶1,四丁基溴化铵用量为钾盐物质的量的2%,在100℃反应10h,反应摩尔收率可达80%以上。

The intermediate, potassium salt of tetrahydro-carbazol-4-one was synthesized from tetrahydro-carbazol-4-one and KOH at first, in the presence of tetrabutyl ammonium bromide （TBAB） as the phase transfer catalyst （PTC）, N,N-dimethylformamide （DMF） as the solvent, and dimethyl carbonate（DMC）as the methylating reagent. Then N-methy-l,2,3,4-tetrahydrocarbazole-g-one was prepared by methylation of the intermedi- ate. The best yield（~〉80%） of N-methy-l,2,3,4-tetrahydrocarbazole-4-one was obtained under the optimized conditions： n（DMC）：n（tbe intermediate）= 2.5：1, n（TBAB）/n（potassium salt）=2% （molar ratio）, the reaction temperature was 100 °C and the reaction time was 10h. The molar yield of this reac- tion could reach over 80%.