Synthesis of 5-bromo-ferulaic acid

5-bromine ferulic acid synthesis process was inversitigated.5-bromine vanillin was synthesised from vanillin using N-bromobutanimide as brominating reagent.5-bromine ferulic acid was prepared from 5-bromine vanillin and malonic acid by Knoevenagel condensation reaction with petroleum ether as reaction solvent instead of benzene.Methylene chloride is the best solvent for this reaction.The reaction conditions were optimized by orthogonal experiments.The optimum reaction conditions of 5-bromine vanillin is n(vanillin)∶n(N-bromobutanimide)=1∶1.5 for 1.0 h and on room temperature.The total yield of 5-bromine ferulic acid is 75.2%.This method has the advantages of high yield,mild reaction conditions,short time,low price reagent,friendly to environment and reuse of the succinimide.