反应详情

A solution of 5-chloro-3-(4-hydroxypiperidinocarbonylmethyl)benzothiazolin-2-one (3.2 g) in dry dioxane (70 ml) was gradually dropped in a phosgene solution in dry dioxane (10 ml), under cooling. The mixture was left for two hours at room temperature. After cooling, to the mixture was gradually dropwise added 28% aqueous ammonia (5 ml) and the resultant was stirred for two hours at room temperature. Dioxane was evaporated off under vacuum from the reaction mixture. The residue was washed with water and then recrystallized from a mixture of dioxane and ethanol to yield the title compound as colorless crystals (2.8 g). m.p. 210°-212° C.

1. temperatureunder cooling
2. temperatureAfter cooling, to the mixture
3. customDioxane was evaporated off under vacuum from the reaction mixture
4. washThe residue was washed with water
5. customrecrystallized from a mixture of dioxane and ethanol