5-Bromo-2,3-dimethylbenzoic acid synthesis

Yield:5613-27-4 83%

Reaction Conditions:

with bromine;nitric acid in water;acetic acid at 20; for 1.5 h;

Steps:

22 5-Bromo-2, 3-dimethyl-benzoic acid

To a solution of 2,3-dimethylbenzoic acid (5 g, 33.3 mmol, 1.0 eq) in acetic acid (167 mL) at room temperature was added a solution of cone, nitric acid (25.2 g, 399 mmol, 12 eq), water (15 g, 0.83 mmol, 25 eq) and bromine (5.85 g, 36.6 mmol, 1.1 eq). A solution of silver nitrate (7.35 g, 43 mmol, 1.3 eq) in water (43 mL) was then added dropwise over 30 min. Once addition was completed, the reaction was stirred at room temperature for 1 h, then quenched by addition of water and EtOAc. The aqueous layer was extracted with EtOAc and the combined organic extracts were washed with water and brine, dried ( a₂S04), filtered and evaporated in vacuo to give the title compound as a yellow solid (6.4 g, 83 %).LC-MS: m/z 228.4 [M+H]⁺

References:

WO2013/37705,2013,A2 Location in patent:Page/Page column 130; 131