Synthesis of nipagin ester in ionic liquid.

Nipagin ester was synthesized in ionic liquid+BF4-.The optimum reaction conditions were obtained by orthogonal experimental method: n(p-hydroxy benzoic acid): n(methyol) = 1∶4.reaction temperature:backflow,reaction time:4 h.The yield was reached 88.9%.The ionic liquid+BF4-had significant catalytic activity in synthesis of nipagin ester.The reaction condition was mild,nonexpendable,non-corrosive,the ionic liquid can be reused.