[CH2:1]([O:3][C:4]([C:6]1[CH:7]=[C:8]2[C:13](=[CH:14][CH:15]=1)[C:12]([Br:16])=[N:11][NH:10][C:9]2=[O:17])=[O:5])[CH3:2].[H-].[Na+].Br[CH:21]([CH3:24])[CH2:22]O>CN(C=O)C>[CH2:1]([O:3][C:4]([C:6]1[CH:7]=[C:8]2[C:13](=[CH:14][CH:15]=1)[C:12]([Br:16])=[N:11][N:10]([CH:21]([CH3:24])[CH3:22])[C:9]2=[O:17])=[O:5])[CH3:2]1-bromo-4-oxo-3,4-dihydro-phthalazine-6-carboxylic acid ethyl ester (6 g, 0.02 mol) was dissolved in DMF (60 ml). To this was added NaH (60%, 0.97 g, 0.024 mol) as a DMF suspension (5 ml). The mixture was stirred at RT for 30 min then 2-bromo-propanol (3.7 g, 0.03 mol) was added in one portion as a solution in DMF (5 ml). The reaction mixture was stirred for 48 hours whereupon LC-MS showed complete consumption of starting material. The DMF was removed under vacuum and the resulting residue was partitioned between DCM (100 ml) and water (100 ml), the organic layer was dried (MgSO4), filtered and concentrated under vacuum. The resulting yellow oil was recrystallised from MeOH to give the title compound (2.3 g, 34% yield) as a white solid. Tr=1.75 min, m/z (ES+) (M+H)+ 339 & 341
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