Hydrochloric Acid → 4-Bromo-2,6-dinitroaniline

Participants

Reaction Conditions

Reaction Steps

A mixture of sodium sulfide nonahydrate (96 g, 400 mmol) and sulfur (12.8 g, 400 mmol) in a mixture of 400 mL of water and 100 mL of ethanol was heated at reflux under nitrogen for 1 h. The solution was added to a stirred suspension of 2-bromo-4,6-dinitrobenzenamine (104.8 g, 400 mmol) and ammonium chloride (20.8 g, 400 mmol) in a mixture of 400 mL of water and 700 mL of ethanol. The mixture was stirred at 65° C. for 30 min. Then 400 mL of 2N NaOH solution was added dropwise during a period of 30 min and the mixture was then stirred for a further 15 minutes at 65° C. After cooling, the mixture was poured onto a mixture of 2N HCl (400 mL), 1 kg ice and 1 L of water, stirred for 15 min to complete the reaction and extracted with ethyl acetate (1 L×3). The combined organic layers were dried over sodium sulphate and evaporated to give the crude product (90 g, 97%) as a rust-colored solid, which was used for the next step without further purification; LC/MS: MS (ES+) m/e 232 [M+H]+; 1H NMR (300 MHz, DMSO-d6) δ ppm 5.48 (s, 2H), 6.07 (s, 2H), 7.39 (d, J=2.7 Hz, 1H), 7.64 (d, J=2.7 Hz, 1H).

Provenance & Evidence