Phosphorus oxychloride → 4-Chloro-1-(2-chlorophenyl)-2-oxo-1,2-dihydropyridine-3-carbonitrile

Participants

Reaction Conditions

Reaction Steps

To a solution of 4-chloro-1-(2-chlorophenyl)-3-((hydroxyimino)methyl)pyridin-2(1H)-one obtained in Step C (968 mg) in acetonitrile (6.80 mL) was added phosphorus oxychloride (0.319 mL) at room temperature. The reaction mixture was heated at 90° C. for 1 hr, cooled to room temperature, and poured into ice water, and the mixture was neutralized with saturated aqueous sodium hydrogen carbonate solution under ice-cooling. The aqueous layer was extracted with ethyl acetate. The extract was washed with water, and dried over anhydrous magnesium sulfate, and the solvent was evaporated under reduced pressure to give the title compound (891 mg). 1H NMR (400 MHz, CDCl3) δ 6.47 (1H, d, J=7.6 Hz), 7.35 (1H, dd, J=7.6, 1.6 Hz), 7.39 (1H, d, J=7.6 Hz), 7.42-7.50 (2H, m), 7.60 (1H, dd, J=7.6, 1.6 Hz).

Provenance & Evidence