99-61-6

355134-13-3

General procedure for the synthesis of 3-bromo-5-nitrobenzaldehyde from m-nitrobenzaldehyde: 3-nitrobenzaldehyde (1.0 g, 6.6 mmol) was dissolved in concentrated sulfuric acid (4.0 mL) at room temperature, followed by batchwise addition of N-bromosuccinimide (1.4 g, 7.9 mmol). The reaction mixture was heated to 65 °C and maintained at this temperature for 1 hour. After completion of the reaction, it was cooled to room temperature and the reaction solution was slowly poured into ice water, the solid was precipitated and collected by filtration. The crude product was dried with anhydrous sodium sulfate and purified by recrystallization through a solvent mixture of ethyl acetate/petroleum ether (1:10, v/v) to finally obtain 3-bromo-5-nitrobenzaldehyde (1.3 g, 82% yield) as white crystals. The structure of the product was confirmed by 1H NMR (300 MHz, DMSO-d6): δ 10.09 (s, 1H), 8.79-8.55 (m, 2H), 8.51 (s, 1H).