6-BroMo-3-Methoxy-2-nitrobenzoic acid synthesis

Yield:127971-97-5 100%

Reaction Conditions:

with sulfuric acid;bromine;silver sulfate at 20; for 2 h;

Steps:

89.A

Step A:; To a mixture of 3-methoxy-2-nitrobenzoic acid (2.5 g, 12.7 mmol) and silver sulfate (2.0 g, 6.4 mmol) in concd sulfuric acid (50 mL) was added bromine (2.03 g, 12.7 mmol), then the reaction mixture was stirred at room temperature in the dark for 2 h. Water was then added, and the resulting precipitate was collected. The solid was dissolved in acetone and the residue was filtered off. The filtrate was dried (MgSO₄), filtered and concentrated to afford the brominated product (2.64 g, 75%) as an off-white solid: ¹H NMR (500 MHz, DMSO-d₆) δ 14.50 (br s, 1H), 7.92 (d, J=9.0 Hz, 1H), 7.42 (d, J=9.0 Hz, 1H), 3.93 (s, 3H).

References:

US2006/183769,2006,A1 Location in patent:Page/Page column 41-42