反应详情

N-(2,6-difluorophenylsulphonyl)urea in an amount of 2.36 and 1.40 g of 2-pyrazoline in 20 ml of dioxane are refluxed for 4 hours. After evaporation of the solvent at reduced pressure, the remaining solid is dissolved in 20 ml of water. This solution is filtrated and acidified with conc. hydrochloric acid. The precipitate is sucked off, washed with water and dried, yielding the title product, viz. 1-(2,6-difluorophenylsulphonylcarbamoyl)-2-pyrazoline in a yield of 1.87 g; melting point 183° C.

1. customAfter evaporation of the solvent at reduced pressure
2. dissolutionthe remaining solid is dissolved in 20 ml of water
3. filtrationThis solution is filtrated
4. washwashed with water
5. customdried