反应详情

Using a method similar to that of Example 4, 6.0 g (29.5 millimoles) of 6-(p-aminophenyl)-4,5-dihydro-5-methyl-3(2H)-pyridazinone are reacted with 4.7 g (35.4 millimoles) of 2,2-dimethylcyclopropanecarboxylic acid chloride in 150 ml of absolute tetrahydrofuran. The mixture is concentrated to about 70 ml, water is added and the product is filtered off, washed with water and recrystallized twice from dimethylformamide/water, giving 5.8 g (66% of theory) of 4,5-dihydro-6-[p-(2,2-dimethylcyclopropylcarbonylamino)-phenyl]-5-methyl-3(2H)-pyridazinone as colorless crystals, of melting point 222°-223° C.

1. concentrationThe mixture is concentrated to about 70 ml, water
2. additionis added
3. filtrationthe product is filtered off
4. washwashed with water
5. customrecrystallized twice from dimethylformamide/water