Hydrochloric Acid → 1-[2-(Methylamino)phenyl]ethan-1-one

A mixture of 2'-chloroacetophenone (182 g), industrial methylated spirit (290 ml), methylamine (33% w/w solution in industrial methylated spirit, 3)3 ml) and copper powder (2.8 g) was stirred in a sealed pressure vessel for 5 hours at 90°. The reaction vessel was allowed to cool to ambient temperature and the mixture washed out of the vessel with industrial methylated spirit (2×100 ml). The combined reaction mixture and washings were stirred at 50°, a solution of sodium sulphide nonahydrate (24 g) in water (100 ml) was added over a period of 10 minutes, and stirring and heating were continued for a further 15 minutes. The mixture was filtered through diatomaceous earth (sold under the trade name CELITE) and the filter bed washed with industrial methylated spirit (100 ml). The filtrate was evaporated to give an oil which was stirred with hydrochloric acid (5M, 800 ml) for 1 hour. The resultant mixture was extracted with dichloromethane (600 ml, then 2×300 ml) and the combined extracts were washed with water (500 ml), dried over magnesium sulphate and evaporated to give an oil which was then distilled. The fraction distilling at 100°-110° and 5 mmHg was collected to give 2'-(methylamino)acetophenone, m.p. 36°-38°. The aqueous acid phase from above was basified by the addition of aqueous sodium hydroxide (specific gravity 1.5, 230 ml). The resultant mixture was extracted with dichloromethane (500 ml, then 250 ml) and the combined extracts were washed with water (300 ml), dried over magnesium sulphate and evaporated to give an oil. Trituration with petroleum ether (b.p. 40°-60°, 200 ml) gave a second crop of 2'-(methylamino)acetophenone, m.p. 36°-38°.

1. washthe mixture washed out of the vessel with industrial methylated spirit (2×100 ml)
2. customThe combined reaction mixture and washings
3. stirringwere stirred at 50°
4. stirringstirring
5. temperatureheating
6. waitwere continued for a further 15 minutes
7. filtrationThe mixture was filtered through diatomaceous earth (
8. washwashed with industrial methylated spirit (100 ml)
9. customThe filtrate was evaporated
10. customto give an oil which
11. extractionThe resultant mixture was extracted with dichloromethane (600 ml
12. wash2×300 ml) and the combined extracts were washed with water (500 ml)
13. dry with materialdried over magnesium sulphate
14. customevaporated
15. customto give an oil which
16. distillationwas then distilled
17. distillationThe fraction distilling at 100°-110°
18. custom5 mmHg was collected

ORD record

ord-fe8a6a7561714be89ce82688eba7d9ba

Source dataset

uspto-grants-1991_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04997840