Phosphorus oxychloride → 4-Chloro-3-nitropyridine

Participants

Reaction Steps

To a suspension of 3-nitro-4-pyridinol (20 g, 143 mmol) in toluene (300 mL) was added phosphorous oxychloride (65.7 g, 429 mmol) at 0° C. The resulting mixture was warmed to room temperature, then heated to reflux (110° C.) for 16 hours. After cooling to rt, the solvent was removed in vacuo and the residue was poured on ice, then basified with K2CO3 to pH≈10. The mixture was extracted with ethyl acetate and the organic phase was washed twice with water, followed by once with brine before concentrating to a brown oil which solidified on standing (22.5 g, 99%). MS (ES+) m/e 159 [M+H]+.

Provenance & Evidence