反应详情

A solution of 2.8 g. (0.02 mole) of 4-cyano-3-methoxyisothiazole prepared as in Example 18 in 30 ml. of 75% sulfuric acid was heated at 70° C. for 0.5 hour. The solution was then cooled and poured into ice to give after filtration and drying 0.95 g. of 4-carbamoyl-3-methoxyisothiazole, m.p. 165°-168° C. By continuous ether extraction of the aqueous filtrate an addition 1.13 g. of 4-carbamoyl-3-methoxyisothiazole was obtained to give a total yield of 2.08 g. (66%).

1. temperatureThe solution was then cooled
2. additionpoured into ice
3. customto give
4. filtrationafter filtration
5. customdrying 0.95 g
6. extractionBy continuous ether extraction of the aqueous filtrate
7. additionan addition 1.13 g