2-Bromopropane → 7-Nitro-2-Isopropyl-4-bromo-2H-phthalazin-1-one

Participants

Reaction Steps

A mixture of 6-nitro-4-bromo-2H-phthalazin-1-one and 7-nitro-4-bromo-2H-phthalazin-1-one (84 g, 0.31 mol) was dissolved in DMF (400 ml). To this was added NaH (60%, 7.5 g, 0.31 mol) as a DMF suspension (200 ml). The mixture was stirred at RT for 30 min then 2-bromo-propane (7.7 g, 62 mmol) was added in one portion as a solution in DMF (250 ml). The reaction mixture was stirred for 24 hours whereupon LC-MS showed 40% starting material remaining. To this was added NaH (3.75 g, 0.15 mol) and the reaction stirred for a further 24 hours. The DMF was removed under vacuum and the resulting crude material purified by successive column chromatography (elution: 92% heptane, 8% EtOAc) to give the title compound (38.8 g, 40% yield) as a light yellow solid. δH (400 MHz, DMSO), 8.88 (1H, d), 8.87 (1H, dd), 8.16 (1 H, d), 5.19 (1H, m), 1.13 (6H, d).

Provenance & Evidence