Acetaldehyde → methyl 5-bromo-3-(ethyl(tetrahydro-2H-pyran-4-yl)amino)-2-methylbenzoate

Participants

Reaction Steps

To a stirred solution of methyl 5-bromo-2-methyl-3-[(oxan-4-yl)amino]benzoate (39.1 g, 119 mmol) in CH2Cl2 (400 mL) and AcOH (40 mL) was added acetaldehyde (24.7 g, 476 mmol) and sodium triacetoxyborohydride (79.6 g, 357 mmol). The reaction mixture was stirred at RT for 24 hours. Then saturated NaHCO3 aq. was added and the mixture was separated. The aqueous layer was extracted with CH2Cl2 and the combined organic layer was concentrated in vacuo. The residue was purified by silica gel column chromatography (SiO2Heptane/EtOAc=3/1) to give the titled compound as a viscous oil (44.1 g, quantitative yield). 1H-NMR (400 MHz, DMSO-d6) δ ppm; 7.62 (s, 1H), 7.52 (s, 1H), 3.80 (m, 5H), 3.31 (m, 2H), 2.97-3.05 (m, 2H), 2.87-2.96 (m, 1H), 2.38 (s, 3H), 1.52-1.61 (m, 2H), 1.37-1.50 (m, 2H), 0.87 (t, J=6.8 Hz, 3H).

Provenance & Evidence