Boron tribromide → 6-(4-Hydroxyphenyl)-2-methyl-3(2H)-pyridazinone

Participants

Reaction Steps

To 6-(4-methoxyphenyl)-2-methyl-2H-pyridazin-3-one (10 g, 46.3 mmol) in 15 mL DCM cooled on an ice-water bath to ˜5° C. was added 93 mL of BBr3 (1M soln in DCM) over 5 min. The ice bath was removed and the solution stirred at rt for 4 h. The reaction was cooled on an ice-bath and saturated NH4Cl solution (100 mL) added slowly. After the addition was complete, the DCM was removed under reduced pressure, excess water added and the product collected, washed 1× with MeOH (˜20 mL) and dried to give 9.2 g (98%): Mp 242-245° C. 1H NMR (DMSO-d6) δ 3.8 (s, 3H), 6.85 (d, 2H), 7.0 (d, 1H), 7.7 (d, 2H), 7.95 (d, 1H), 9.8 (s, 1H); MS m/z=203 (M+H).

Provenance & Evidence