Phosphorus oxychloride → 6-Bromo-4-chloropyrido[2,3-d]pyrimidine

Participants

Reaction Steps

6-Bromopyrido[2,3-d]pyrimidin-4(3H)-one (3.0 g) and POCl3 (15 mL) were heated at 130° C. under nitrogen for 3 h. The homogeneous dark solution was concentrated under reduced pressure and diluted with EtOAc (150 mL). The heterogeneous brown slurry was poured onto mixture of ice/aq. NaHCO3 and allowed the mixture warm to room temperature. The heterogeneous brown mixture was further diluted with EtOAc (75 mL) and separated the organic layer. The organic layer was partitioned with aq. NaCl, separated, stirred with MgSO4 and filtered through a pad of Celite® and silica gel. The pale yellow filtrate was concentrated and the crude solid was stirred in 50% EA/hexanes. 6-Bromo-4-chloropyrido[2,3-d]pyrimidine was obtained as a pale yellow crystalline solid (1.8 g, purity: 95%) upon filtration.

Provenance & Evidence