反应详情

51.5 g of 2-(2-hydroxyphenyl)benz[e][1,3]oxazin-4-one, 30.5 ml of triethylamine and 33.4 g of ethyl hydrazinoacetate hydrochloride are boiled under reflux for 0.5 h in 450 ml of ethanol. On cooling, the product precipitates in crystalline form. It is filtered off and washed with ethanol. After drying, ethyl [3,5-bis(2-hydroxyphenyl)-[1,2,4]triazol-1-yl]acetate remains as colorless crystals of m.p. 172-174° C.

1. temperatureOn cooling
2. customthe product precipitates in crystalline form
3. filtrationIt is filtered off
4. washwashed with ethanol
5. customAfter drying