Phosphorus tribromide → Ethyl-3-bromomethyl-4-oxo-3-H-phthalazin-1-ylacetate
Reaction equation
[CH2:1]([O:3][C:4](=[O:19])[CH2:5][C:6]1[C:15]2[C:10](=[CH:11][CH:12]=[CH:13][CH:14]=2)[C:9](=[O:16])[N:8]([CH2:17]O)[N:7]=1)[CH3:2].P(Br)(Br)[Br:21]>CCOCC>[CH2:1]([O:3][C:4](=[O:19])[CH2:5][C:6]1[C:15]2[C:10](=[CH:11][CH:12]=[CH:13][CH:14]=2)[C:9](=[O:16])[N:8]([CH2:17][Br:21])[N:7]=1)[CH3:2]Participants
4
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Procedure
A solution of ethyl-3-hydroxymethyl-4-oxo-3-H-phthalazin-1-ylacetate (13.1 g), phosphorous tribromide (13.5 g) and anhydrous ether (250 ml) was stirred overnight at room temperature. It was then poured onto water (200 ml). The organic layer was collected, washed again with water (3×100 ml) and then dried over anhydrous sodium sulfate. The dried organic extract was evaporated to dryness and the resulting crude solid was purified by chromatography on silica gel, eluting with 95% CH2Cl2- 5% ethyl acetate (percents by volume) to obtain the title compound (yield: 9.8 g; m.p. 96° C.).