Sodium Nitrite → 4-chloro-7-methoxy-1H-pyrazolo[4,3-c]pyridine

Participants

Reaction Conditions

Reaction Steps

A solution of sodium nitrite (98%, 326 mg, 4.63 mmol) in water (0.6 mL) was added to a solution of C4 (200 mg, 1.16 mmol) in acetic acid (8 mL), and the reaction mixture was heated at 75° C. for 1 hour. After the reaction mixture had cooled to room temperature, it was concentrated in vacuo, diluted with saturated aqueous sodium bicarbonate solution, and extracted with ethyl acetate. The combined organic layers were washed with saturated aqueous sodium chloride solution, dried over magnesium sulfate, filtered, and concentrated under reduced pressure. Silica gel chromatography (Gradient: 25% to 50% ethyl acetate in heptane) provided the product as a yellow solid. Yield: 140 mg, 0.763 mmol, 66%. LCMS m/z 184.0 [M+H+]. 1H NMR (400 MHz, CDCl3) δ 8.17 (s, 1H), 7.74 (s, 1H), 4.06 (s, 3H).

Provenance & Evidence