溴化铜对乙酰基愈创木酚的选择性溴化反应

以愈创木酚为起始物,合成了4-乙酰基愈创木酚,然后以4-乙酰基愈创木酚和溴化铜(CuBr2)为反应物,分别用乙酸乙酯与三氯甲烷的混合溶液、甲醇、乙醇作为反应溶剂合成了4-(α-溴代乙酰基)-愈创木酚,并利用红外光谱、核磁共振谱(1H-NMR)等手段对其化学结构进行了分析和确认。研究结果表明,利用甲醇和乙醇作为反应溶剂,将该4-乙酰基愈创木酚的取代反应由非均相转变为均相,得率稳定在90%以上。该溴代反应受反应时间的影响不大。重结晶的方法不能将产物分离,采用硅胶层析用乙酸乙酯和正己烷(1∶2,V/V)作为流动相可分离得到产物。

Selective Bromination with Copper(Ⅱ) Bromide on Acetovanillone

4-bromoacetoguaiacone was synthesized used guaiacol as starting materials.Then 4-(α-bromoacetyl)-guaiacol was synthesized used 4-bromoacetoguaiacone and copper(Ⅱ) bromide as raw material and mixture of ethyl acetate and chloroform(1∶1),ethanol or methanol as reactive solvent.Meanwhile the techniques of TLC、FT-IR and 1H-NMR were used to identify the chemical structure.The results obtained showed that taking alcohol or ethanol as a substitute of mixture of ethyl acetate and chloroform as solvent can change this bromide reaction from nonhomophase to homophase and the yield reached 90%.The reaction time had little effect on the final yield.The recrystallization by benzene can not separate the final product.The final product can be obatained by column chromatography using the mixture of n-hexane and ethyl acetate(2∶ 1) as mobile phase.