反应详情

50 g of the sulfonamide obtained in Example 6 are suspended in 150 ml of 1,2-dichloroethane and the suspension is treated with 27.7 ml of thionyl chloride. The mixture is heated at the boil for 4 hours, cooled to 50°-55° C. and treated with 0.5 ml of pyridine, and phosgene is passed for 31/2 hours into the solution which has now been brought to the boil. The mixture is concentrated under reduced pressure with the exclusion of moisture. The crude sulfonyl isocyanate which remains (52.6 g) crystallises upon standing.

1. temperatureThe mixture is heated at the boil for 4 hours
2. temperaturecooled to 50°-55° C.
3. custom2 hours
4. concentrationThe mixture is concentrated under reduced pressure with the exclusion of moisture
5. customcrystallises