Propanoic acid, 2-bromo-2-methyl-, ethyl ester → HCID 23000312, compound

Participants

Reaction Steps

0.606 g of 6-[3-[4-(diphenylmethoxy)piperidino]propylamino][1,2,4]triazolo[4,3-b]pyridazin-3(2H)-one was suspended in 3 ml of N,N-dimethylformamide; 0.063 g of 60% oily sodium hydride was added,-followed by stirring at room temperature for 1 hour. 0.253 ml of ethyl 2-bromoisobutyrate was added, followed by stirring in an oil bath (bath temperature 80° C.) for 17 hours. After cooling, 0.063 g of 60% oily sodium hydride and 0.253 ml of ethyl 2-bromoisobutyrate were added, followed by stirring in an oil bath (bath temperature 80° C.) for 3 hours. After cooling, ice water was added; the reaction mixture was extracted with ethyl acetate; the extract was washed with saturated saline and dried over magnesium sulfate. After concentration under reduced pressure, the residue was subjected to silica gel column chromatography and eluted with ethyl acetate-methanol-triethylamine (90:10:1). The desired fraction was collected and concentrated to yield 0.38 g of ethyl 2-[6-[3-[4-(diphenylmethoxy)piperidino]propylamino]-3-oxo[1,2,4]triazolo[4,3-b]pyridazin-2(3H)-yl]-2-methylpropionate as an oily substance. This oily substance was dissolved in 5 ml of ethyl acetate; 0.5 ml of a 4 N solution of hydrogen chloride in ethyl acetate was added, followed by concentration; the residue was powdered from diethyl ether, collected by filtration, and dried, to yield 0.342 g of the title compound.

Provenance & Evidence