Dimethyl Sulfoxide → 4-Methyl-2-{6-[3-(2-methylpyrrolidin-1-yl)propoxy]pyridin-3-yl}-4,5-dihydro-1,3-oxazole-4-carbaldehyde

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Reaction Conditions

Reaction Steps

A solution of oxalyl chloride (0.38 ml, 4.32 mmol) in dichloromethane (30 ml) is cooled to −78° C. and is treated slowly with dimethylsulfoxide (0.51 ml, 7.2 mmol). After 20 min at −78° C., a solution of (4-methyl-2-{6-[3-(2-methylpyrrolidin-1-yl)propoxy]pyridin-3-yl}-4,5-dihydro-1,3-oxazol-4-yl)methanol ax56 (1.2 g, 80% purity, ca. 3.0 mmol) in dichloromethane (10 ml) is added dropwise over 10 min. After 60 min at −78° C., triethylamine (2.5 ml, 18 mmol) is added and the mixture is allowed to warm to 22° C. Water is then added and after vigorous stirring, the organic layer is separated and the aqueous phase extracted twice with dichloromethane. The combined organic layers are washed with brine, dried over sodium sulfate and concentrated in vacuo to yield 1.2 g of ca. 80% pure 4-methyl-2-{6-[3-(2-methylpyrrolidin-1-yl)propoxy]pyridin-3-yl}-4,5-dihydro-1,3-oxazole-4-carbaldehyde ax57.

Provenance & Evidence