反应详情

A mixture of 3.05 g (0.01 mole) of methyl 4-(3,5-dichloro-4-methylphenyl)-2-methoxy-4-oxobutyrate, 0.6 g (0.012 mole) of hydrazine monohydrate and 30 ml of methanol was heated under reflux for 3.5 hours. 1.1 ml of concentrated hydrochloric acid was then added to the mixture, after which it was again heated under reflux for a further 6 hours. At the end of this time, the solvent was distilled off and the residue was washed, in turn, with water and with a small amount of diethyl ether, after which it was dried to give 1.80 g of the desired product. The washings were extracted with ethyl acetate and the extract was dried over anhydrous sodium sulphate, after which the organic solvent was distilled off. The residue was washed in turn with benzene and with diethyl ether, to give a further 0.11 g of the desired product. The total yield of 6-(3,5-dichloro-4-methylphenyl)-3(2H)pyridazinone was 1.91 g (74.9%) and the properties of the product were identical with those of the products of Examples 1(d), 2 and 3.

1. temperaturewas heated
2. temperatureunder reflux for 3.5 hours
3. temperatureafter which it was again heated
4. temperatureunder reflux for a further 6 hours
5. distillationAt the end of this time, the solvent was distilled off
6. washthe residue was washed, in turn, with water and with a small amount of diethyl ether
7. customafter which it was dried