反应详情

Into a four-necked flask of 1 liter, 43 g of ethylmagnesium bromide (3 mol/liter of an ether solution) and 200 ml of dehydrated toluene were charged. While thoroughly stirring the mixture at room temperature, 22.1 g (0.1 mol) of 2-t-butyl-4,5-dichloro-3(2H)pyridazinone was added in three portions. The reaction temperature was raised to a level of about 60° C., and the stirring was continued for about 30 minutes. The disappearance of the starting dichloropyridazinone was confirmed by thin layer chromatography (developer; hexane:acetone =20:1, v/v), whereupon the reaction was terminated. After the addition of about 300 ml of chilled water, the mixture was stirred vigorously, and transferred to a separating funnel, and then the aqueous layer was removed. The organic layer was washed with about 200 ml of water, and dried over anhydrous sodium sulfate, and then the solvent was distilled off. The pale brown oily substance thereby obtained was purified by silica gel column chromatography (developer; benzene) to obtain pale yellow crystals. 1.45 g (yield: 67.6%).

1. temperatureThe reaction temperature was raised to a level of about 60° C.
2. customhexane:acetone =20:1, v/v), whereupon the reaction was terminated
3. additionAfter the addition of about 300 ml of chilled water
4. stirringthe mixture was stirred vigorously
5. customtransferred to a separating funnel
6. customthe aqueous layer was removed
7. washThe organic layer was washed with about 200 ml of water
8. dry with materialdried over anhydrous sodium sulfate
9. distillationthe solvent was distilled off
10. customThe pale brown oily substance thereby obtained
11. customwas purified by silica gel column chromatography (developer; benzene)
12. customto obtain pale yellow crystals