反应详情

A 269 g. portion of 6-(p-chlorophenyl)-3(2H)-pyridazinone and 1500 ml. of phosphorus oxychloride are heated on a steam bath for 5 hours. The excess phosphorus oxychloride is removed under vacuum. The solid concentrate is diluted with ice water and the resulting solid is recovered by filtration, washed with water and dried. This product is recrystallized twice from dimethylformamide-water yielding 6-(p-chlorophenyl)-3-chloropyridazine as an off-white solid, m.p. 202°-204° C.

1. customThe excess phosphorus oxychloride is removed under vacuum
2. concentrationThe solid concentrate
3. additionis diluted with ice water
4. filtrationthe resulting solid is recovered by filtration
5. washwashed with water
6. customdried
7. customThis product is recrystallized twice from dimethylformamide-water