Dimethylformamide → 6-Bromo-4-methoxypyrazolo[1,5-a]pyridine-3-carbaldehyde

Participants

Reaction Steps

Phosphorous oxychloride (513 μl, 5.51 mmol) was added to DMF (8.52 ml, 110 mmol) at 0° C. The bath was removed and the solution was allowed the solution to warm to ambient temperature. After 30 minutes, 6-bromo-4-methoxypyrazolo[1,5-a]pyridine (500 mg, 2.202 mmol) was added, and the mixture was allowed to stir at ambient temperature. After 3.5 h, the reaction was quenched by the addition of saturated aqueous sodium bicarbonate (30 mL) and stirred for 60 minutes. The reaction mixture was diluted in ethyl acetate, washed with saturated aqueous sodium hydrogen carbonate and brine then dried over sodium sulfate, filtered and concentrated. The solid was placed under vacuum overnight to remove excess DMF and afford 6-bromo-4-methoxypyrazolo[1,5-a]pyridine-3-carbaldehyde contaminated with about 9% of the starting material.

Provenance & Evidence