Hydrochloric Acid → 5-Chloro-2-methylaniline

Participants

Reaction Steps

57 g of hydrogen chloride (= 1.56 mols) were introduced, while thoroughly stirring, into a solution of 160 g of distilled o-toluidine (= 1.5 mols) in 1300 ml of chlorobenzene in the course of 30 - 45 minutes. It is advisable but not necessary to cool the reaction mixture slightly in a water bath. 105 g of chlorine gas (= 1.48 mols) were introduced at 35°C within 13/4 hours. Then, the hydrogen chloride still in solution was blown out with air. The hydrochloride was suction-filtered through a Buchner funnel and dried in the air. To isolate the free 5-chloro-2-toluidine the dried filter residue was introduced portionwise into 350 g of sodium hydroxide solution (18%). The temperature rose to about 40° - about 50°C. Then, the crude amine was separated in a separating funnel and subjected to a fractionated distillation under reduced pressure. The amount of product obtained was 60.1 g of 2-toluidine (= 0.56 mol), which was reused, 101.0 g of 5-chloro-2-toluidine (= 0.71 mol) corresponding to 75.5 % calculated on reacted 2-toluidine (introduced 2-toluidine minus 2-toluidine recovered) and 14.3 g of 3.5-dichlorotoluidine (= 0.08 mol).

Provenance & Evidence