Sodium hydride → Isopropyl 2-[6-[3-[4-(diphenylmethoxy)piperidino]propoxy)-7-methylimidazo[1,2-b]pyridazin-2-yl]-2-methylpropionate

Participants

Reaction Steps

To 10 ml of N,N-dimethylformamide, 0.16 g of a 60% dispersion of sodium hydride in mineral oil and 1.30 g of 4-(diphenylmethoxy)-1-piperidinepropanol were added, followed by stirring at room temperature under reduced pressure for 1 hour. While the reaction mixture was cooled with ice water, 1.31 g of isopropyl 2-(6-chloro-7methylimidazo[1,2-b]pyridazin-2-yl)-2-methylpropionate was added, followed by stirring at room temperature for 1.5 hours. To the reaction mixture, ice water was added, followed by extraction with ethyl acetate; the extract was washed with saline and dried with magnesium sulfate. The dry product was concentrated under reduced pressure; the residue was subjected to silica gel column chromatography and eluted with hexane:ethyl acetate (1:5). The desired fraction was collected to yield 582 mg of isopropyl 2-[6-[3-[4-(diphenylmethoxy)piperidino]propoxy]-7-methylimidazo[1,2-b]pyridazin-2-yl]-2-methylpropionate as an oily substance. This oily substance was dissolved in 4 ml of ethanol; 2 ml of a 1 N aqueous solution of sodium hydroxide was added and reaction mixture was heated under reflux for 7 hours. After cooling, reaction mixture was concentrated under reduced pressure followed by extraction with ethyl acetate-tetrahydrofuran (1:1); the extract was washed with saturated saline and dried with magnesium sulfate. The dry product was concentrated under reduced pressure; the residue was crystallized by the addition of a small amount of water and ethyl ether, collected by filtration, washed with ethyl ether and dried to yield 0.413 g of the title compound.

Provenance & Evidence