Acetic Acid → methyl 5-bromo-2-methyl-3-((tetrahydro-2H-pyran-4-yl)amino)benzoate

Participants

Reaction Steps

To a stirred solution of methyl 3-amino-2-methyl-5-bromobenzoate (4.06 g, 16.6 mmol) in DCE (60 ml) under a nitrogen atmosphere was added oxan-4-one (3.07 ml, 33.3 mmol) followed by acetic acid (5.71 ml, 99.8 mmol) and the reaction was left to stir for 5 min before the addition of sodium triacetoxyborohydride (10.6 g, 49.9 mmol). The reaction was stirred for 3 h at room temperature whereupon distilled water (50 ml) was added and the solution was neutralised with solid NaHCO3. The phases were separated and then the aqueous phase was washed with EtOAc (2×100 ml), the combined organics were then dried using Na2SO4, filtered and evaporated. The residue was purified by FCC using silica and eluting with a 10% to 40% EtOAc in heptane gradient to afford the title compound as an off-white solid (3.88 g, 71%). LC-MS 100%, 2.10 min (3.5 minute LC-MS method), m/z=327.9/329.8, 1H NMR (500 MHz, Chloroform-d) δ 7.23 (d, J=1.9 Hz, 1H), 6.84 (d, J=1.7 Hz, 1H), 4.02 (dt, J=11.7, 3.5 Hz, 2H), 3.87 (s, 3H), 3.65 (d, J=7.2 Hz, 1H), 3.59-3.45 (m, 3H), 2.23 (s, 3H), 2.05 (d, J=13.8 Hz, 2H), 1.51 (ddd, J=24.1, 10.8, 4.2 Hz, 2H).

Provenance & Evidence