Yield:313346-23-5 90%

Reaction Conditions:

with chlorosulfonic acid at 20 - 75;Temperature;

Steps:

jlntermediate 84J - 5-(Chlorosulfonyl)-2,4-dimethylbenzoic acid

2,4-Dimethylbenzoic acid (1.50 g 1 mmol) was added in portions with stirring to chlorosulfonic acid (5 ml) at 20 °C. The reaction was stirred at 70-75 °C overnight. The reaction was added dropwise with stirring to 2OOg ice / water. The beige precipitate was collected and washed well with water with filtration. The solid was taken up in ethyl acetate, dried over Na2SO4, filtered and concentrated in vacuo to yield the title compound as a pale grey solid (2.36g, 90%).1H NIVIR (500 MHz, Chloroform-d) 8.76 (s, 1H), 7.38 (s, 1H), 2.83 (s, 3H), 2.76 (s, 3H).

References:

WO2018/89433,2018,A1 Location in patent:Paragraph 00368; 00623