METHOD FOR THE PREPARATION OF 2-METHOXY-4-(N-T-BUTYLAMINO-CARBONYL)-BENZENESULFONYL CHLORIDE

摘要

2-Methoxy-4-(N-t-butylamino-carbonyl) benzenesulfonyl chloride is prepared via new intermediates. Preparation of 2-methoxy-4-(N-t butylamino-carbonyl)-benzenesulfonyl chloride (I) comprises: (a) sulfonating m-hydroxybenzoic acid (II) with 96% sulfuric acid to give 3-hydroxy-4-sulfobenzoic acid, or a salt (III); (b) methylating (III) in the presence of a phase transfer catalyst at pH 11.5 to give (IV); (c) transforming (IV) to the acid chloride 4-chlorosulfonyl-3-methoxy-benzoyl chloride (V); and (d) reacting (V) with t-butylamine in equimolar amounts or in a small excess, in the presence of an acid binding agent, in aprotic solvent at low temperature to give (I). [Image] Z : alkali metal or ammonium. Independent claims are included for new compounds (III) and (IV).