反应详情

1-(4-Fluorophenyl)-1,4-dihydro-4-oxo-6-methylpyridazine-3-carboxylic acid (1.5 g) is suspended in 100 ml of dry methanol, and 0.242 g of sodium hydroxide is added. To the solution is added dropwise 1.038 g of bromine dissolved in 50 ml of methanol. The solvent is removed leaving a white solid, which is taken up in dilute base and the solution acidified with hydrochloric acid. The resulting precipitate is filtered and recrystallized from chloroform/ether to yield 1.4 g of 1-(4-fluorophenyl)-5-bromo-1,4-dihydro-4-oxo-6-methylpyridazine-3-carboxylic acid. (mp-219°-20°).

1. customThe solvent is removed
2. customleaving a white solid, which
3. filtrationThe resulting precipitate is filtered
4. customrecrystallized from chloroform/ether