反应详情

5.0 g (26.4 millimoles) of 6-(p-aminophenyl)-4,5-dihydro-3(2H)-pyridazinone, 4.2 g (31.7 millimoles) of 2,2-dimethylcyclopropanecarboxylic acid chloride in 100 ml of absolute tetrahydrofuran are refluxed for 7 hours. The mixture is concentrated to about 50 ml and the product is filtered off at 10° C., washed with water and recrystallized from dimethylformamide/water. 5.2 g (68% of theory) of 4,5-dihydro-6-[p-(2,2-dimethylcyclopropylcarbonylamino)-phenyl]-3(2H)-pyridazinone quarter-hydrate are obtained as almost colorless crystals, of melting point 213°-214° C.

1. concentrationThe mixture is concentrated to about 50 ml
2. filtrationthe product is filtered off at 10° C.
3. washwashed with water
4. customrecrystallized from dimethylformamide/water