2-乙基苯并噁唑的微波超声波辅助合成

以2-氨基苯酚、丙酸为原料,多聚磷酸为催化剂,微波超声波辅助合成了2-乙基苯并噁唑.通过考察原料与催化剂摩尔配比,反应温度,反应时间等因素的影响,得出较佳工艺条件为:微波和超声波功率分别为800 W,2-氨基苯酚与丙酸的摩尔配比为1:5.5,催化剂多聚磷酸与2-氨基苯酚的摩尔配比为0.52:1,130℃,反应时间15 min.反应液经萃取、减压蒸馏处理,得含量为99.78%的产物,产率47.96%,产物结构通过质谱、红外光谱和核磁共振进行了确认.产物具有浓郁的青香、咸香、清甜、凉香气特征,与2-甲基苯并噁唑相比,香气差别较大.

Synthesis of 2-Ethylbenzoxazole Assisted with Microwave and Ultrasonic Wave

2-Ethylbenzoxazole was synthesized using 2-aminophenol and propionic acid as the reagents and polyphosphoric acid(PPA)as the catalyst assisted with microwave and ultrasonic wave.The influences of mole ratio of catalyst to reactant,reaction temperature,and reaction time were investigated.The optimum technology found was microwave power 800 W,ultrasonic wave power 800 W,the mole ratio of propionic acid to 2-aminophenol in 5.5:1,the mole ratio of PPA to 2-aminophenol in 0.52:1,reaction temperature 130 ℃,and reaction time 15 min.After extracted and distilled in vacuum,the concentration of product of 2-ethylbenzoxazole reached to 99.78% with the yield of 47.96 %.Compared to 2-methylbenzoxazole,organoleptic characteristics of 2-ethylbenzoxazole was significantly different,which smelled green,salty,sweet,and cool.The structure of 2-ethylbenzoxazole was confirmed by IR,MS and 1H-NMR.