反应详情

温度

80 °C

7.5 ml of chlorosulfonic acid was stirred at room temperature under an inert atmosphere. 5 g of 2-aminobenzoxazol (6-2) was added in small portions. The temperature was kept between 30-60° C. during the addition of 6-2. The mixture was heated to 80° C. for 2 hours. 5.3 g of thionyl chloride was added drop wise, keeping the temperature at 65° C. The mixture was stirred during 2 hours. After cooling to 0° C. 10 ml of ethyl acetate and 10 ml of a solution of sodium carbonate (1N) were added. The organic layer was separated from the water layer and this latter was extracted with ethyl acetate. The combined organic layers were dried over calcium chloride, yielding 7.8 g (90%) of 2-amino-6-chlorosulfonylbenzoxazole (63).

1. additionThe temperature was kept between 30-60° C. during the addition of 6-2
2. customat 65° C
3. temperatureAfter cooling to 0° C
4. customThe organic layer was separated from the water layer
5. extractionthis latter was extracted with ethyl acetate
6. dry with materialThe combined organic layers were dried over calcium chloride