Process for the preparation of 2-[alkyl(aryl)]sulfonylbenzene-sulfonyl chlorides and their intermediates

Abstract

A process for the preparation of 2-[alkyl(aryl)]sulfonylbenzene sulfonyl chlorides of the following formula is provided: in which R is alkyl or aryl substituted at the ortho or meta positions with alkyl, aryl, NHAc or alkoxy, comprising the steps of: a) reacting 2-chloronitrobenzene, 2-fluoronitrobenzene or 2-bromonitrobenzene with a compound of the following formula: RSO2−M+ wherein R is defined above; and M is sodium, potassium, lithium, ammonium or quaternary ammonium, in a polar aprotic solvent at a temperature of about 50 to 190° C.; b) reacting the material prepared in step (a) with hydrogen at a pressure of about 20 to about 60 psi in a polar aprotic solvent at a temperature of about 20 to about 60° C.; and c) diazotizing the material prepared in step (b) with sodium nitrite in the presence of hydrochloric acid and reacting the resulting diazonium salt with sulfur dioxide in the presence of copper (I) or copper (II) compounds or a mixture thereof, in water.

Dependencies are inferred from the claim text.