Iodine → N-Methyl-3-(trifluoromethyl)-benzeneethanamine

Temperature

0 °C

At 0° C., a solution of iodine (23.1 g, 91 mmol) in tetrahydrofuran (100 ml) was added dropwise to a suspension of sodium borohydride (8.6 g, 227 mmol) and of N-methyl-2-(3-trifluoromethylphenyl)acetamide (19.8 g, 91 mmol) in THF (150 ml). The reaction mixture was heated to reflux for 16 hours. It was cooled to 0° C. Methanol (200 ml) was added dropwise. The solvent was removed in vacuo. The residue was dissolved in a mixture of tert-butyl methyl ether (200 ml) and a 20% aqueous solution of sodium hydroxide (200 ml). The phases were separated. The aqueous phase was extracted with tert-butyl methyl ether (2×100 ml). The combined organic layers were dried over magnesium sulphate. The solvent was removed in vacuo. The crude product was purified by flash chromatography on silica (300 g), using a mixture of DCM/methanol/25% aqueous ammonia (first: 100:10:1, then 100:20:2, then 100:30:3) as eluent, to give 3.77 g of N-methyl-N-[2-(3-(trifluoromethyl)phenyl)ethyl]amine.

1. temperatureThe reaction mixture was heated
2. temperatureto reflux for 16 hours
3. customThe solvent was removed in vacuo
4. dissolutionThe residue was dissolved in a mixture of tert-butyl methyl ether (200 ml)
5. customThe phases were separated
6. extractionThe aqueous phase was extracted with tert-butyl methyl ether (2×100 ml)
7. dry with materialThe combined organic layers were dried over magnesium sulphate
8. customThe solvent was removed in vacuo
9. customThe crude product was purified by flash chromatography on silica (300 g)
10. additiona mixture of DCM/methanol/25% aqueous ammonia (first: 100:10:1

ORD record

ord-1c24dbd33ba448e7adc29c3e7c90bd3d

Source dataset

uspto-grants-2002_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06437147B1