反应详情

6.54 ml of 1,8-diazabicyclo[5.4.0]undec-7-ene are added to 12.1 g (0.0436 mole) of 3,4-dihydro-2,2-dioxo-3-methyl-1,2-benzoxathiin-8-ylsulfonamide in dioxane. While cooling with ice, 2.65 ml of methyl isocyanate are added dropwise. The reaction mixture is stirred for 2 hours at 20° to 25° C., then diluted with water, neutralised with 10 ml of 5% sodium carbonate solution, and filtered. Acidification of the filtrate yields 12.0 g (91% of theory) of N-(3,4-dihydro-2,2-dioxo-3-methyl-1,2-benzoxathiin-8-ylsulfonyl)-N'-methylurea.

1. additionare added dropwise
2. filtrationfiltered