Dimethyl Sulfoxide → 2-Methylpyrazolo[1,5-A]pyridine-4-carbaldehyde

Participants

Reaction Steps

Under nitrogen atmosphere, to a solution of oxalyl chloride (18.9 mL, 216 mmol) in dichloromethane (200 mL) was added dimethyl sulfoxide (35.4 mL, 499 mmol) at −78° C., and the mixture was stirred for 30 min. To the reaction mixture was added a solution of (2-methylpyrazolo[1,5-a]pyridin-4-yl)methanol (27.0 g, 166 mmol) in dichloromethane (133 mL), and the mixture was stirred for 2 hr. To the reaction mixture was added triethylamine (117 mL, 831 mmol) at −78° C., and the mixture was stirred for 1 hr and warmed to room temperature. After concentration under reduced pressure, the residue was purified by silica gel column chromatography (ethyl acetate/hexane=1/1) to give the title compound (7.00 g, yield 26%).

Provenance & Evidence