5-broMo-2,4-dichloro benzoic acid synthesis

Yield:791137-20-7 99.08%

Reaction Conditions:

with chlorosulfonic acid;bromine;sulfur at 70; for 16 h;

Steps:

74.1 Step 1:

Step 1:
5-Bromo-2,4-dichlorobenzoic acid
To a solution of 2,4-dichlorobenzoic acid (10.00 g, 52.35 mmol) in chlorosulfonic acid (50.00 mL) was added bromine (4.18 g, 26.18 mmol, 1.34 mL) and sulfur (83.94 mg, 2.62 mmol).
The reaction mixture was heated to 70° C. for 16 h.
The reaction was monitored by LCMS, when the reaction was complete, it was cooled and poured on ice (50 g), filtered, dissolved in EtOAc (300 mL), washed with water (200 mL), dried and concentrated to get 5-bromo-2,4-dichloro-benzoic acid (14.00 g, 51.87 mmol, 99.08%). MS (EI⁺, m/z): 190.96[M+H]⁺

References:

US2018/127370,2018,A1 Location in patent:Paragraph 1099; 1097