反应详情

To a solution of 1.0 g (6.06 mmole) 3-amino-1-methyl5-trifluoromethylpyrazole in 15 ml 6N hydrochloric acid, 0.52 g (7.44 mmole) sodium nitrite in 2 ml water was added slowly dropwise at 5° C. The mixture was stirred for 1.5 hours at the same temperature. Then 3.35 g (14.85 mmole) tin chloride (SnCl2.2H2O) in 3 ml concentrated hydrochloric acid was added dropwise. The mixture was warmed to room temperature, stirred for 2 hours and made basic by addition of 8N caustic soda under ice cooling. The residue was extracted with methylene chloride, dried over sodium sulfate and concentrated. 0.85 g 3-hydrazino-1-methyl-5-trifluoromethylpyrazole was obtained which was treated without further purification.

1. stirringstirred for 2 hours
2. extractionThe residue was extracted with methylene chloride
3. dry with materialdried over sodium sulfate
4. concentrationconcentrated