反应详情

To a solution of 6-oxo-1,4,5,6-tetrahydropyridazine-3-carboxylic acid (20 g) in acetic acid (50 mL) is added 25% hydrobromic acid/acetic acid (200 mL) and thereto is added dropwise dimethylsulfoxide (22.0 g) at room temperature. The mixture is stirred at room temperature for 3 days. The resultant precipitates are collected by filtration, washed successively with acetic acid and water and dried at 40° C. overnight to give 6-oxo-1,6-dihydropyridazine-3-carboxylic acid (10.55 g, yield; 54%) as colorless crystals. MS (ESI) m/z: 139 [M−H]−

1. customThe resultant precipitates
2. filtrationare collected by filtration
3. washwashed successively with acetic acid and water
4. customdried at 40° C. overnight