Diisopropylethylamine → HCID 89793768, compound

Participants

Reaction Steps

A solution of 1-(3-fluoro-2-methylquinoxalin-5-yl)ethanone (126g) (0.65 g, 3.19 mmol), tert-butyl (2-amino-2-methylpropyl)carbamate (1.20 g, 6.37 mmol), and DIEA (2.22 mL, 12.75 mmol) in NMP (6.37 mL) was stirred at 170° C. for 1.5 h when mostly product was observed via lcms. The reaction mixture was diluted with DCM (100 mL), added to a separatory funnel, and washed with saturated aq. brine (4×100 mL); the organic layer was separated, dried over Na2SO4, and concentrated. The crude product was adsorbed onto silica and was purified via automated flash chromatography (silica gel) with 10-40% EtOAc in hexanes to give tert-butyl (2-((8-acetyl-3-methylquinoxalin-2-yl)amino)-2-methylpropyl)carbamate (339a) (0.78 g, 2.09 mmol, 65% yield) as a honey colored solid. 1H NMR (400 MHz, CDCl3) δ ppm 1.48 (s, 9H) 1.57 (s, 6H) 2.55 (s, 3H) 2.87 (s, 3H) 3.33 (d, J=6.85 Hz, 2H) 5.25 (t, J=6.55 Hz, 1H) 6.53 (s, 1H) 7.32 (t, J=7.73 Hz, 1H) 7.73 (dd, J=7.34, 1.47 Hz, 1H) 7.88 (dd, J=8.02, 1.37 Hz, 1H). MS (ESI, pos. ion) m/z: 373.2 (M+1).

Provenance & Evidence