Abstract: Aim ：The tandem Claisen rearrangement/Diels-Alder reaction in ionic liquid was carried out to find better changes for the conversion. Methods ：The synthesis started with replaced benzoic acid via acylation，cyclization，demethylation，allylation and then tandem Claisen rearrangement/Diels-Alder reaction in trational solvent and ionic liquid separately. Results ：BmimBF₄ raised the yield of the target compound and shortened the reaction time compared with the traditional solvent. Conclusion ：BmimBF₄ can promote the tandem Claisen rearrangement/Diels-Alder reaction.