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

Participants

Reaction Steps

To a solution of methyl 3-amino-5-bromo-2-methylbenzoate (3.0 g, 12 mmol) in 1,2-Dichloroethane (48 ml) under nitrogen, was added oxan-4-one (2.3 ml, 25 mmol) followed by acetic acid (4.2 ml, 74 mmol). The reaction mixture was stirred for 5 minutes before the addition of sodium triacetoxyborohydride (7.8 g, 37 mmol). After stirring for 64 hours, deionized water (100 ml) was added and the mixture was neutralized with solid NaHCO3. The phases were separated and the aqueous layer was extracted with EtOAc (4×50 ml). The combined organic extracts were dried over MgSO4, filtered and concentrated in-vacuo. The residue was purified by flash column chromatography (50 g silica, Isolute cartridge, 10-30% EtOAc:Heptanes) to give the title compound (3.5 g 85%) as a white solid. LC-MS 99.8%, 2.18 min (3.5 minute LC-MS method), m/z=327.9, 328.9, 329.9, 330.9; 1H NMR (500 MHz, Chloroform-d) δ ppm 7.24 (d, J=1.73 Hz, 1H) 6.85 (d, J=1.58 Hz, 1H) 4.03 (dt, J=11.82, 3.31 Hz, 2H) 3.88 (s, 3H) 3.66 (br.s., 1H) 3.56 (td, J=11.55, 1.97 Hz, 2H) 3.47-3.55 (m, 1H) 2.24 (s, 3H) 2.06 (d, J=13.56 Hz, 2H) 1.47-1.60 (m, 2H).

Provenance & Evidence