Sodium Bicarbonate → Methyl 3-{[(2R*,6R*)-1-benzyl-2,6-dimethylpiperidin-4-yl]amino}-2-methyl-5-(trifluoromethyl)benzoate

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of methyl 3-amino-2-methyl-5-(trifluoromethyl)benzoate (400 mg, 1.72 mmol) in THF (15 mL) and TFA (491 uL) was added (2R,6S)-1-benzyl-2,6-dimethylpiperidin-4-one (410 mg, 1.89 mmol) at 0° C. The mixture was stirred at 60° C. for 1 hour under nitrogen atmosphere. Then the mixture was cooled to 0° C. in an ice bath, sodium triacetoxyborohydride (765 mg, 3.43 mmol) was added. The reaction mixture was stirred at 23° C. for 2 hours. Then aq. NaHCO3 was added at 0° C. until pH8-9, and the content was extracted with ethylacetate. The organic layer was dried over MgSO4 and filtered. The filtrate was concentrated in vacuo. The residue was purified by silica gel column chromatography (NH—SiO2; heptane/ethylacetate=3/1) to give the titled compound as a colorless oil. (278 mg, 37% yield). 1H-NMR (400M Hz, CDCl3) δppm; 7.21-7.40 (m, 6H), 6.90 (s, 1H), 3.95 (d, J=14.0 Hz, 1H), 3.90 (s, 3H), 3.60-3.73 (m, 2H), 3.46 (d, J=14.0 Hz, 1H), 3.08-3.12 (m, 1H), 2.98-3.03 (m, 1H), 2.30 (s, 3H), 2.02-2.08 (m, 1H), 1.83-1.88 (m, 1H), 1.52-1.60 (m, 1H), 1.17-1.26 (m, 1H), 1.11 (d, J=6.8 Hz, 3H), 1.13 (d, J=6.4 Hz, 3H).

Provenance & Evidence