Hydrochloric Acid → 2-Chloro-6-ethylbenzoic acid

Participants

Reaction Conditions

Reaction Steps

3.60 g (21.2 mmol) of 2-chloro-6-ethylaniline in 60 ml of acetic acid is introduced into a reaction vessel and the clear, colourless solution is cooled to 6° C. At that temperature, 3.64 g (22.7 mmol) of a 43% aqueous sodium nitrite solution are added and then, in the course of 15 minutes, a solution of 4.32 g (42.4 mmol) of sulfuric acid (96%) in 7 ml of acetic acid is added dropwise. The resulting dark-red solution is then stirred for 30 minutes. When a diazo colour test, for example using dimethylaniline-coated indicator paper, is positive and a colour spot test, e.g. using KI indicator paper moistened with aqueous 1 N hydrochloric acid solution, is negative, 15 mg of sulfamic acid are added and then, at a temperature of 10° C., 8.7 ml (91.6 mmol) of acetic anhydride are added. The reaction mixture is then transferred to a glass autoclave and rinsed with 20 ml of acetic acid. At a temperature of 20° C. the autoclave is flushed out three times with nitrogen and then flushed out three times with CO. 220 mg of Pd2(dba)3.CHCl3 (0.212 mmol) in 5 ml of acetic acid are then metered in using a cannula at a CO pressure of 1 bar, then a CO pressure of 8 bar is applied and the reaction mixture is stirred overnight at 45° C.

Provenance & Evidence