反应详情

12.75 g of 6-(3,5-dichloro-4-methylphenyl)-3-pyridazone and 22 g of phosphorus pentasulphide in 80 ml of pyridine were heated under reflux on an oil bath for 7 hours. The reaction mixture was then cooled to room temperature and its volume was reduced by one-half by distilling off the pyridine under reduced pressure. 300 ml of ethyl acetate were added to the residue and the mixture was poured into ice-water. After stirring the mixture for a short time, the resulting yellow solid was collected by filtration, washed with water and dried to give 7.5 g (56%) of the desired compound. After recrystallizing the compound from a 10:1 by volume mixture of ethanol and dioxan, the compound melted at 255°-258° C.

1. temperatureunder reflux on an oil bath for 7 hours
2. distillationby distilling off the pyridine under reduced pressure
3. addition300 ml of ethyl acetate were added to the residue
4. additionthe mixture was poured into ice-water
5. filtrationthe resulting yellow solid was collected by filtration
6. washwashed with water
7. customdried