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

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°.

1. temperatureheated
2. temperatureunder reflux overnight
3. temperatureThe mixture was cooled to 20°
4. temperatureThe mixture was heated at 100° for 30 minutes
5. temperaturecooled to 20°
6. extractionThe mixture was extracted with dichloromethane (2×400 ml)
7. dry with materialthe combined extracts were dried over magnesium sulphate
8. customThe solvent was removed by evaporation under reduced pressure
9. customthe residue purified by flash chromatography on a silica gel column
10. washeluted with dichloromethane

ORD record

ord-e5dd314e94d94a62819afc1ad901b026

Source dataset

uspto-grants-1991_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04997840