TBAB相转移催化合成7-烷氧基香豆素

Catalytic Synthesis of 7-Alkoxylcoumarins by TBAB

以四正丁基溴化铵(TBAB)作相转移催化剂,7-羟基香豆素(1)或7-羟基-4-甲基香豆素(2)与5种卤代烃经Williamson反应合成了10个新的7-烷氧基香豆素,其结构经1H NMR,IR和MS表征。Williamson反应的优化条件为:以丙酮为溶剂,在碘化钾存在下,1或25mmol,n(1或2)∶n(卤代烃)∶n(碳酸钾)∶n(TBAB)=1.0∶1.5∶2.5∶0.1,于60℃～100℃反应5h～8h,产率84%～96%。

Ten novel 7-alkoxylcoumarins were synthesized by Williamson reaction of 7-hydroxycouma- rin（1） or 7-hydroxy4-methylcoumarin（2） and five alkyl halides using tetrabutylammonium bromide （TBAB） as a phase transfer catalyst. The structures were characterized by 1H NMR, IR and MS. Optimum conditions of Williamson reaction in acetone in presence of KI at 60℃ -80 ℃ for 5 h ~ 8 h were as follows： 1（or 2） was 5 mmol; n（1 or 2） ： n（alkyl halide） ： n（K2CO3） ： n（TBAB） = 1.0 ： 1.5 ： 2.5 ： 0.1. The yields were 84% - 96% under the optimum conditions.