Hydrochloric Acid → 3-Chloro-2-methylbenzenesulfonyl chloride

Participants

Reaction Conditions

Reaction Steps

30 gm (0.212 mol) of 3-chloro-2-methyl-aniline were admixed with 50 ml of concentrated aqueous hydrochloric acid. The reaction mixture was cooled to between -7° and -3° C. and at this temperature a solution of 14.6 gm (0.212 mol) of sodium nitrite in 50 ml of water was added dropwise thereto over a period of 1 hour. After stirring for a further hour at 0° C., 20.3 gm (0.1 mol) of magnesium chloride hexahydrate were added, and the reaction mixture was stirred for 10 minutes and then filtered. The filtrate was poured into a suspension of 12 gm (71 mmols) of copper (II)chloride in 250 ml of a 30% solution of sulfur dioxide in glacial acetic acid. During the addition the temperature of the reaction mixture rose from 20° C. to 40° C., accompanied by a strong evolution of gas. After stirring for 60 minutes at room temperature and for 60 minutes at 35° C., 500 gm of ice were added. The mixture was stirred until the ice had melted, and then filtered.

Provenance & Evidence