3,4,5-三甲氧基苯甲醛的合成工艺改进

Improvement of the Synthetic Process of 3,4,5-Trimethoxy Benzaldehyde

用对羟基苯甲醛与溴反应生成3,5-二溴-4-羟基苯甲醛和HBr,3,5-二溴-4-羟基苯甲醛用氯化亚铜作催化剂,在DMF溶剂中与甲醇钠反应生成3,5-二甲氧基-4-羟基苯甲醛(丁香醛),丁香醛在pH=9用硫酸二甲酯甲基化得到3,4,5-三甲氧基苯甲醛。反应中生成的HBr和NaBr氧化成溴供循环使用。

P - hydroxy benzaldehyde reacts with bromine to form 3,5 - bromo - 4 - hydroxy benzaldehyde ,then fwthes reaction occurs with sodium methylate to obtain 3,5 -methoxy -4 -hydroxy benzaldehyde in the solution of DMF and employing cuprous chloride as catalyst. In the end, this compound is methylafed by bimethyl sulphade to synthesize 3,4,5 -trimethoxy benzaldehyde at pH 9. The sodium bromine and hydrobromine in the reaction can circularly use.