Water → 1-(2-Chlorophenyl)-2-(pyridin-4-yl)ethanamine

Temperature

50 °C

To a solution of 1-(2-chlorophenyl)-2-(pyridin-4-yl)ethanone (22) (2.0 g, 8.7 mmol) in pyridine (24 mL) was added methoxyl amine hydrochloride (1.45 g, 17.4 mmol) in one portion at room temperature. The resulting mixture was stirred at 50° C. for one hour. The pyridine was removed under vacuum, and residue was added water and extracted with ethyl acetate. Ethyl acetate phase was washed with brine, dried over magnesium sulfate and concentrated. Purification by chromatography on silica gel gave a mixture of geometrical oxime isomers (1.77 g, 78%) as a yellow oil. To a solution of above mixture of syn- and anti-oximes, (1.77 g, 6.8 mmol) in THF (32 mL) at room temperature was added borane-THF complex (1M, 17 mL). The resulting solution was refluxed for 3 hours, and cooled to 0° C. Water (28 mL) was carefully added followed by 20% NaOH (28 mL). The resulting biphasic mixture was refluxed overnight, and allowed to cool to room temperature. The mixture was extracted with ethyl acetate. Combined ethyl acetate phase was washed with brine, dried over magnesium sulfate and concentrated to give 1-(2-chlorophenyl)-2-(pyridin-4-yl)ethanamine (23) (1.2 g 76%) as yellow oil.

1. customThe pyridine was removed under vacuum, and residue
2. additionwas added water
3. extractionextracted with ethyl acetate
4. washEthyl acetate phase was washed with brine
5. dry with materialdried over magnesium sulfate
6. concentrationconcentrated
7. customPurification by chromatography on silica gel
8. customgave
9. additionwas added borane-THF complex (1M, 17 mL)
10. temperatureThe resulting solution was refluxed for 3 hours
11. temperaturecooled to 0° C
12. temperatureThe resulting biphasic mixture was refluxed overnight
13. temperatureto cool to room temperature
14. extractionThe mixture was extracted with ethyl acetate
15. washCombined ethyl acetate phase was washed with brine
16. dry with materialdried over magnesium sulfate
17. concentrationconcentrated

ORD record

ord-30aa4702647a44f0913ef4338cb9dc73

Source dataset

uspto-grants-2014_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08735399B2