Nitric Acid → 1-Bromo-2-fluoro-3,5-dinitrobenzene

Participants

Reaction Conditions

Reaction Steps

To 1-fluoro-2,4-dinitrobenzene (13.0 g, 69.85 mmol, 1 equiv) dissolved in sulfuric acid (190 mL) at room temperature was added bromine (4.30 mL, 83.82 mmol, 1.2 equiv) dropwise followed by the slow dropwise addition of nitric acid (70%, d=1.500; 3.25 mL, 76.84 mmol, 1.1 equiv). The reaction vessel was fitted with a refluxing condenser, and the reaction mixture was heated at 80° C. for 10 hours. LCMS indicated a reactant:product ratio of 1:1. After allowing to cool to room temperature, the mixture was poured into ice and diluted with DCM. The aqueous and organic layers were partitioned, and the aqueous extracted with DCM (2×300 mL). The combined organic extracts were washed with saturated Na2S2O3 (2×200 mL), dried (Na2SO4), filtered, and concentrated to dryness. The crude product was purified using a pad of silica gel and eluted with EtOAc/hexanes (25-35% EtOAc in increments of 5% EtOAc) to give the product 1-bromo-2-fluoro-3,5-dinitrobenzene (5.55 g, 30%) as a light-yellow solid.

Provenance & Evidence