Phosphorus oxychloride → 2,4-Dichloro-5-nitropyridine

Participants

Reaction Conditions

Reaction Steps

The product from Step 2 (40.0 g, 229 mmol) was suspended in toluene (300 mL) and POCl3 (65 mL, 697 mmol) was added over 10 min, then the mixture was heated to relux for 6 h then cooled to 60° C. and allowed to stir overnight at that temperature. The heterogeneous mixture was cooled and concentrated, the residue was carefully made basic with aq. K2CO3 solution and extracted with EtOAc. The organic layers were combined, washed with H2O and brine, dried (Na2SO4), filtered and the filtrate was concentrated to give an oil. The crude oil was passed through a plug of silica gel (50% EtOAc in hexanes) to give the title compound (32.5 g, 74%) as an orange oil which solidified on standing. MS (ES+) m/e 194 [M+H]+.

Provenance & Evidence