Benzyl Bromide → 2-Benzyl-4,5-dichloro-2,3-dihydropyridazin-3-one

Participants

Reaction Steps

To a solution of dichloropyridazinone (50.0 g, 303.0 mmol) in DMF (200 mL) was added K2CO3 (50.3 g, 364.0 mmol) at RT under vigorous stirring. Benzylbromide (40.0 mL, 336.0 mmol) was added in rapid drops via a syringe. The resulting suspension was stirred at 50° C. for 1 h until all the pyridazinone was consumed as judged by HPLC. The reaction mixture was then poured into water (400 mL). The resultant suspension was stirred for 15 min at RT, and then filtered. The collected solid was rinsed thoroughly with water until no color was apparent in the filtrate. The solid was dried in a vacuum oven at 50° C. overnight to give the title compound, 2-benzyl-4,5-dichloropyridazin-3(2H)-one, (73.1 g, 95%) as pale yellow solid. HPLC: 3.17 min; MS, M+H=255.

Provenance & Evidence