反应详情

To a mixture of 230 ml of concentrated sulphuric acid and 230 ml of 100% nitric acid, 26 g of 3-chloro-6-(3,5-dimethyl-1-pyrazolyl)-pyridazine are added portionwise, under stirring at a temperature between 0° C. and 5° C., then the mixture is stirred at room temperature for 2 hours, poured into 1 liter of water and set aside overnight in the refrigerator. The separated crystals are filtered, washed with water and dried. Yield: 26.7 g (84.5%); m.p. 164°-167° C.

1. additionare added portionwise
2. stirringthe mixture is stirred at room temperature for 2 hours
3. filtrationThe separated crystals are filtered
4. washwashed with water
5. customdried