Benzoic acid, 2-bromo-4,5-dimethoxy-, ethyl ester synthesis

Yield:17667-33-3 83%

Reaction Conditions:

with sulfuric acid for 72 h;Reflux;

Steps:

121.1

A solution of 2-bromo-4,5-dimethoxy-benzoic acid (30.0 g, 115 mmol) and sulfuric acid (2.8 g, 1.5 mL, 28 mmol) in ethanol (300 mL) was heated to reflux and stirred for 72 hours. The mixture was concentrated to approximately 20 mL in vacuo, diluted with saturated aqueous NaHCO₃ (300 mL) and extracted with ethyl acetate (3 × 300 mL). The combined organic phases were washed with brine (300 mL), dried over Na₂SO₄, filtered and concentrated to provide ethyl 2-bromo-4,5-dimethoxy-benzoate (27.97 g, 83%) as a yellow solid. ESI-MS m/z calc.288.00, no ionization observed; LC/MS retention time (Method N): 4.98 minutes

References:

WO2020/146682,2020,A1 Location in patent:Paragraph 00773