Water → 5-Bromo-6-phenylpyridazin-3(2H)-one

Reaction equation

Br[C:2]1[C:3](=O)[O:4][CH:5]([C:8]2[CH:13]=[CH:12][CH:11]=[CH:10][CH:9]=2)[C:6]=1[Br:7].[NH2:15][NH2:16].O>CCO>[Br:7][C:6]1[C:5]([C:8]2[CH:13]=[CH:12][CH:11]=[CH:10][CH:9]=2)=[N:16][NH:15][C:3](=[O:4])[CH:2]=1

Participants

Procedure

To a solution of 3,4-dibromo-5-phenylfuran-2(5H)-one (4.951 g, 15.57 mmol) in EtOH (5 mL) at 0° C. was added hydrazine, H2O (0.840 mL, 17.13 mmol). The reaction mixture was stirred at room temperature for 10 min before heating to reflux for 2 h. The reaction was cooled to room temperature. The precipitate formed was collected by filtration and washed with cold ethanol to yield the title compound as a pale yellow solid (2.530 g). LCMS m/z=351 [M+H]+; 1H NMR (400 MHz, DMSO-d6) δ ppm 7.47-7.49 (m, 3H), 7.51-7.54 (m, 3H).