4-Bromo-3-methyl-5-(chlorosulfonyl)benzoic acid synthesis

Yield:849333-58-0 66.8%

Reaction Conditions:

with chlorosulfonic acid at 0; for 4.5 h;Heating / reflux;

Steps:

1c

Example 1 c:4-Bromo-3-chlorosulfonyl-5-methyl-benzoic acidChlorosulfonic acid (150 mL, 2.18 mol) was added slowly to compound of Example 1b (74 g, 0.344 mol) at O⁰C. The reaction mixture was refluxed for 4.5 h and then was poured into ice-cold water (1500 mL) with stirring. The solid was filtered, washed with water till filtrate was neutral and dried to obtain the title compound. Yield: 72.40 g (66.8%); ¹H NMR (DMSOd₆, 300 MHz): δ 2.40 (s, 3H, CH₃), 7.80 (S, 1 H, Ar)₁ 8.30 (s, 1 H, Ar); MS: m/e (ES-) 315 (M-1).

References:

WO2006/51477,2006,A2 Location in patent:Page/Page column 54