反应详情

43 g of 8-amino-1,4-benzodioxane-5-carboxylic acid and 72 ml of acetic acid were introduced into a balloon flask and then 24.5 ml of acetic anhydride were added in portions. The mixture was heated to 60°-70° C. and then cooled. The precipitate was dried off, washed with acetic acid and water and dried. 44 g of 8-acetamino-1,4-benzodioxane-5-carboxylic acid were obtained (M.P.: 233° C.; yield: 84%).

1. temperatureThe mixture was heated to 60°-70° C.
2. temperaturecooled
3. customThe precipitate was dried off
4. washwashed with acetic acid and water
5. customdried