Diethyl Malonate → Diethyl 2-(2-nitro-4-(4-nitrobenzoyl)phenyl)malonate

Participants

Reaction Conditions

Reaction Steps

NaH, 60% dispersion in mineral oil, (1.27 g, 31.7 mmol) was washed with petroleum ether then suspended in anhydrous DMSO (30 mL). Diethyl malonate (4.85 mL, 31.7 mmol) was dissolved in 8 mL of anhydrous DMSO and added dropwise to the NaH suspension. The mixture was allowed to stir for 15 min at 100° C., during which time the reaction mixture became homogeneous. (4-Bromo-3-nitro-phenyl)-(−4-nitro-phenyl)-methanone (5.15 g, 14.4 mmol) was dissolved in anhydrous DMSO (15 mL) and subsequently added via syringe to the malonate solution. The mixture was allowed to stir at 100° C. for 2 h after which the reaction was cooled to room temperature and poured into water (˜300 mL). The mixture was extracted with EtOAc (3×300 mL) and dried over anhydrous Na2SO4. The organic layers were then concentrated in vacuo affording a crude black oil. The crude oil was then flashed through a plug of silica with 30% EtOAc/Hexanes. The solution was then concentrated in vacuo yielding a pale yellow solid that contained the desired product contaminated with excess diethyl malonate. The impure solid was washed with Hexanes, filtered and dried affording diethyl [2-nitro-4-(4-nitrobenzoyl)phenyl] malonate in 75% yield (4.64 g, 10.8 mmol).

Provenance & Evidence