反应详情

A solution of 4,5-diamino-1-methylpyrazole sulfate (158 g) in water (1.1 L) was neutralized to pH 6.9 with 4N aqueous sodium hydroxide solution, and dioxane (474 ml) was added to this solution. To the resulting mixture was added dropwise phenyl chloroformate (124 g) maintaining pH of the mixture at 6.9 with 4N aqueous sodium hydroxide solution at a temperature below 10° C. The reaction mixture was stirred for 1 hour. The precipitated solid was collected by filtration and dried to give 5-amino-1-methyl-4-phenoxycarbonylaminopyrazole (155 g).

1. additionwas added to this solution
2. filtrationThe precipitated solid was collected by filtration
3. customdried