Acetic Acid → 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 (2.0 g, 6.1 mmol) in DCE (10 ml) under a nitrogen atmosphere was added acetaldehyde (1.0 ml, 18 mmol) followed by acetic acid (2.1 ml, 37 mmol) and the reaction was left to stir for 5 min before the addition of sodium triacetoxyborohydride (6.6 g, 31 mmol). The reaction was stirred for 16 h at room temperature after which time additional acetaldehyde (1.0 ml, 22 mmol) and sodium triacetoxyborohydride (3.0 g, 14 mmol) were added and the reaction was stirred for a further 6 h whereupon distilled water (100 ml) was added and the phases were separated. The aqueous phase was washed with EtOAc (3×100 ml), the combined organics were then dried using Na2SO4, filtered and evaporated to afford the title compound as a colourless oil (2.10 g, 93%) which was suitable for use without any further purification. LC-MS 96%, 2.38 min (3.5 minute LC-MS method), m/z=356.1/357.9, 1H NMR (500 MHz, Chloroform-d) δ 7.70 (d, J=2.0 Hz, 1H), 7.36 (d, J=2.0 Hz, 1H), 3.95 (d, J=11.3 Hz, 2H), 3.88 (d, J=9.1 Hz, 3H), 3.32 (td, J=11.5, 2.5 Hz, 2H), 3.04 (q, J=7.1 Hz, 2H), 2.98-2.87 (m, 1H), 2.44 (s, 3H), 1.77-1.55 (m, 4H), 0.86 (t, J=7.1 Hz, 3H).

Provenance & Evidence