Formaldehyde → Methyl 3-[ethyl(1-methylpiperidin-4-yl)amino]-2-methyl-5-(trifluoromethyl)benzoate

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of methyl 3-[ethyl(piperidin-4-yl)amino]-2-methyl-5-(trifluoromethyl)benzoate TFA salt (crude material, 5.30 g, 12.0 mmol) in CH2Cl2 (150 mL) and AcOH (10 mL) was added formaldehyde (15 mL, 44% aqueous solution) and sodium triacetoxyborohydride (6.40 g, 30.0 mmol). The reaction mixture was stirred at 23° C. for 2.5 days. Then saturated NaHCO3 was added and the mixture was separated. The aqueous layer was extracted with CH2Cl2 (3×50 mL) and the combined organic layers were concentrated in vacuo. The residue was purified by silica gel column chromatography (NH—SiO2 heptane/EtOAc=2/1) to give the titled compound as oil (1.20 cg, 28% yield). 1H-NMR (400 cMHz, CDCl3) δppm; 7.81 (br. s., 1H), 7.45 (d, J=2.0 Hz, 1H), 3.92 (s, 3H), 3.10 (q, J=7.0 Hz, 2H), 2.83 (m, 2H), 2.66-2.77 (m, 1H), 2.54 (s, 3H), 2.24 (s, 3H), 1.84-1.94 (m, 2H), 1.63-1.78 (m, 4H), 0.86 (t, J=7.0 Hz, 3H); MS (ES) [M+H] 359.1.

Provenance & Evidence