Ethyl Acetate → HCID 21192629, compound

Participants

Reaction Steps

36 g of N,N-dimethylpivalamide was dissolved in 85 ml of toluene; under ice cooling conditions, 11.3 ml of phosphorus oxychloride was added drop by drop, followed by stirring at room temperature for 24 hours. To this solution, 12.0 g of 3-amino-6-chloropyridazine was added, followed by stirring at 60-70° C. for 24 hours. After cooling, ethyl acetate was added; the mixture was washed with a 2 N aqueous solution of sodium hydroxide and saline and dried with sodium sulfate. After the dry product was concentrated under reduced pressure, the residue was subjected to silica gel column chromatography and eluted with hexane:ethyl acetate:triethylamine (50:50:2). The desired fraction was collected to yield 6.38 g of N,N-dimethyl-N′-(6-chloropyridazin-3-yl)pivalamidine. The mother liquor was purified by silica gel column chromatography to yield 6.07 g of the amidine. 12.45 g of the amidine derivative obtained was dissolved in 100 ml of methanol; a solution of 4.31 g of hydroxylamine hydrochloride in methanol was added, followed by stirring at room temperature for 2 hours. The methanol was concentrated to half volume under reduced pressure; the crystal precipitated was collected by filtration, washed with water and ethyl ether and dried to yield 10.44 g of the title compound.

Provenance & Evidence