Phosphorus oxychloride → 4-chloro-1-ethyl-3-nitro-1H-pyridin-2-one

Participants

Reaction Steps

A suspension of 1-ethyl-4-hydroxy-3-nitro-1H-pyridine-2-one (1.0 g, 5.43 mmol) in POCl3 (8.33 g, 54.3 mmol) was heated at refluxed for 1 h. After cooling to room temperature, the solvent was evaporated under reduced pressure and water was carefully added to the chilled residue. The mixture was neutralized with 2 N NaOH, extracted with CHCl3, washed with brine, dried over MgSO4 and concentrated under reduced pressure. The resulting solid was washed with Et2O to give 4-chloro-1-ethyl-3-nitro-1H-pyridin-2-one (0.58 g, 53% yield). 1H-NMR (CDCl3): δ, 7.48 (d, 1H, J=7.6 Hz), 6.37 (d, 1H, J=7.6 Hz), 4.07 (q, 2H, J=7.2 Hz), 1.40 (t, 3H, J=7.2 Hz). MS: calculated for C7H7ClN2O3+H 203.0; found: 203.1.

Provenance & Evidence