Hydrochloric Acid → 2-tert-butyl-5-chloro-4-methylpyridazin-3-(2H)-one

Participants

Reaction Steps

Into 225 ml of a 3.0M diethyl ether solution of methyl magnesium bromide, 170 ml of an absolute ether solution of 74.40 g of 4,5-dichloro-2-tert-butyl-pyridazin-3-(2H)-one was dropwise added under cooling with ice at a temperature of from 5° to 10° C. After completion of the dropwise addition, the mixture was stirred at a temperature of from 5° to 10° C. for two hours. Then, 158 ml of 6N hydrochloric acid was added to the reaction solution, and then 600 ml of diethyl ether was added thereto for liquid separation. The ether layer was washed with a saturated sodium chloride aqueous solution and then dried over anhydrous sodium sulfate. The solvent was distilled off under reduced pressure, and the residue was subjected to silica gel column chromatography. From a fraction of n-hexane:ethyl acetate=9:1, 24.45 g of oily 2-tert-butyl-5-chloro-4-methylpyridazin-3-(2H)-one, was obtained.

Provenance & Evidence