反应详情

3-(4'-Chlorophenyl)-4-hydroxy-6-chloropyridazine (Compound 1, 24.1 g, 0.09997 mol) was initially introduced into a reaction flask and a solution of phosphorus oxybromide (85.8 g, 0.3 mol) in toluene (150 ml) was added, and the reaction mixture was then stirred for one hour at room temperature. The mixture was then refluxed gently for three hours, during which process gaseous hydrogen bromide was given off. The mixture was decomposed on ice, which gave a pasty reaction product, which solidified on trituration with petroleum ether. The product was then washed thoroughly with water, isolated and dried to constant weight. 30.0 g (0.0861 mol, 86.1% of theory) of 3-(4'-chlorophenyl)-4,6-dibromopyridazine of m.p.=160°-162° C. were obtained. Recrystallized from an ethanol/dioxane mixture (20+3), the sample showed a melting point of 163°-165° C.

1. customgave a pasty reaction product, which
2. washThe product was then washed thoroughly with water
3. customisolated
4. customdried to constant weight