Hydrazine hydrate (1:1) → 4-(3-bromobenzyl)-5,7-dimethyl-2,6-dihydro-1H-pyrrolo[3,4-d]pyridazin-1-one

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Reaction Steps

Hydrazine hydrate (0.110 mL, 1.48 mmol) was added to methyl 4-(2-(3-bromophenyl)acetyl)-2,5-dimethyl-1H-pyrrole-3-carboxylate (49) (0.470 g, 1.34 mmol) in acetic acid (20 mL). The resulting solution was stirred at room temperature for 2 days. The reaction mixture was evaporated to dryness and redissolved in EtOAc (200 mL), and washed sequentially with 2M NaOH (100 mL) and saturated brine (50 mL). The organic layer was dried over Na2SO4, filtered and evaporated to afford crude product. The crude product was purified by flash silica chromatography, elution gradient 0 to 100% ethyl acetate in isohexane. Pure fractions were evaporated to dryness to afford the desired material as a beige solid (0.253 g, 56.7% yield); 1H NMR (400.132 MHz, MeOD) δ 2.18 (3H, s), 2.50 (3H, s), 4.03 (2H, s), 7.04-7.11 (2H, m), 7.25 (2H, m); m/z (LC-MS, ESI+), RT=1.84 min (M+H=333.97).

Provenance & Evidence