中文摘要：

以2-氨基苯酚、乙酸为原料,多聚磷酸为催化剂,微波及超声波辅助合成食用香料2-甲基苯骈噁唑。通过考察催化剂与原料物质的量之比、微波和超声波功率、只有微波无超声波、反应温度、反应时间等因素的影响,确定较佳工艺条件：微波和超声波功率均为800W,乙酸与2-氨基苯酚的物质的量之比为7.6：1,催化剂多聚磷酸用量4g,反应温度115℃,时间25min。经减压蒸馏处理后,产率为78.20%。2-甲基苯骈噁唑结构通过质谱、红外光谱和核磁共振进行了确认。本实验所得工艺,原料廉价易得,利用微波和超声波的协同效应,具有反应时间短、收率高、操作简便、产品香气纯正等优点。

英文摘要：

Under the combined assistance of microwave and ultrasonic,the synthesis of 2-methylbenzoxazole for use as a food flavor via the polyphosphoric acid-catalyzed reaction between 2-aminophenol and acetic acid was studied.Experimental investigations into the effects of catalyst type,2-aminophenol-to-acetic acid molar ratio,2-aminophenol-to-polyphosphoric acid（PPA） mass ratio,microwave power,ultrasonic power,microwave treatment alone,reaction temperature and reaction time on reaction yield of 2-methylbenzoxazole were carried out.The results showed that the optimal synthesis conditions of 2-methylbenzoxazole were microwave power of 800 W,ultrasonic power of 800 W,2-aminophenol-to-PPA ratio of 3：4,acetic acid-to-2-aminophenol ratio of 7.6：1,reaction time of 25 min,and reaction temperature of 115 ℃.This optimized reaction and subsequent vacuum distillation resulted in a 2-methylbenzoxazole yield of 78.20%.The structure of the synthesized 2-methylbenzoxazole was confirmed by IR,MS and 1H NMR.The established process for 2-methylbenzoxazole synthesis from the inexpensive and easily available materials had the advantages of short reaction time,high yield and easy operation resulting from the synergistic action of microwave and ultrasonic and allowed the formation of purely aromatic products.