Hydrochloric Acid → 2-Chloro-1-[2-(methylamino)phenyl]ethanone

Participants

Reaction Steps

A solution of N-methylaniline (5.43 ml) in toluene (60 ml) was added dropwise over 20 minutes to a stirred solution of boron trichloride (1M, 50 ml) in hexane at 0 to 5° under nitrogen. Chloroacetonitrile (3.8 ml) and then aluminium trichloride (7.34 g) were added and the mixture was stirred and heated under reflux overnight. The mixture was cooled to 20° and hydrochloric acid (2M, 100 ml) added. The mixture was heated at 100° for 30 minutes, then cooled to 20° and adjusted to pH 3 to 4 with aqueous sodium hydroxide (5M, 50 ml). The mixture was extracted with dichloromethane (2×400 ml) and the combined extracts were dried over magnesium sulphate. The solvent was removed by evaporation under reduced pressure and the residue purified by flash chromatography on a silica gel column eluted with dichloromethane to give 2-chloro-2'-(methylamino)acetophenone, m.p. 65°-68°.

Provenance & Evidence