Phosphorus oxychloride → 6-Bromo-1-chlorophthalazine

Participants

Reaction Conditions

Reaction Steps

A mixture of 6-bromophthalazin-1-ol (10.0 g, 44.4 mmol) in phosphorus oxychloride (104 mL, 1111 mmol) was heated at 105° C. in an oil bath for 3 h. After cooling to RT, the volatiles were removed by vacuum distillation. The residue was diluted with CH2Cl2 and treated with 10% Na2CO3 solution. After stirring for 3 h, the mixture was diluted with 10% Na2CO3 and extracted with CH2Cl2 (3×). The combined organic solution was dried over Na2SO4, filtered through a short pad of silica gel, eluted with EtOAc, and concentrated in vacuo to yield the title compound as a tan solid. MS (ESI, pos. ion) m/z: 242.9, 244.9 (M+1).

Provenance & Evidence