Methylamine → HCID 118098742, compound

Participants

Reaction Steps

To a solution of 20A (635 mg, 2.61 mmol) in MeOH (10 mL), was added methylamine (33% in EtOH) (0.390 mL, 3.13 mmol). The mixture was stirred at rt for 3 h, then was cooled to 0° C. and treated with NaBH4 (119 mg, 3.13 mmol). The reaction was stirred at 0° C. for 2 h, then was concentrated. The residue was dissolved in THF (10 mL), treated with H2O (10 mL) and sat. NaHCO3 (10 mL). After stirring for 10 min, Boc2O (684 mg, 3.13 mmol) was added. The mixture was stirred at rt for 2 h, then the THF was evaporated. The mixture was extracted with EtOAc (2×). The organic phase was washed with H2O and brine, dried (Na2SO4) and concentrated. The crude product was purified by flash chromatography (loaded in chloroform onto a 40 g column and eluted with a gradient from 0 to 40% ethyl acetate/hexanes) to give 20B (864 mg, 2.411 mmol, 92% yield) as a pale yellow oil. MS (ESI) m/z: 381.1 [M+1]+. 1H NMR (400 MHz, chloroform-d) δ ppm 7.80-7.94 (2H, m), 4.68 (2H, d, J=20.6 Hz), 3.60-3.71 (1H, m), 2.92 (3H, d, J=10.5 Hz), 1.53 (5H, s), 1.43 (4H, br. s.), 1.27 (6H, d, J=6.3 Hz), 3:2 ratio of rotamers.

Provenance & Evidence