Phenacyl bromide → Diazoacetophenone

Participants

Reaction Conditions

Reaction Steps

DBU (7.5 mL, 50.2 mmol) was added dropwise to a solution of 2-bromo-1-phenylethanone (2.0 g, 10.05 mmol) and N,N′-bis(p-toluenesulfonyl)hydrazine (6.8 g, 20.1 mmol) in dry THF (30 mL) at 0° C. The reaction mixture was stirred at 0° C. for 30 min, and quenched with aqueous saturated NaHCO3 solution. The organic product was extracted with EtOAc and the combined extracts were washed with brine, dried over anhydrous sodium sulfate, and concentrated under reduced pressure. The crude product was purified by column chromatography (silica 60-120 mesh, eluant 10-15% EtOAc in petroleum ether) to get 2-diazo-1-phenylethanone (1.2 g, yield 82%) as a yellow solid. 1H NMR (300 MHz, CDCl3) δ 7.78-7.76 (m, 2H), 7.56-7.53 (m, 1H), 7.48-7.43 (m, 2H), 5.91 (s, 1H).

Provenance & Evidence