反应详情

A solution of 1-(3-fluoro-2-methylquinoxalin-5-yl)ethanone (126g, 300 mg, 1.469 mmol), 2-methyl-4-(methylsulfonyl)butan-2-amine (338b, 486 mg, 2.94 mmol), and N-ethyl-N-isopropylpropan-2-amine (1.02 mL, 5.88 mmol) in NMP (2.94 mL) was stirred at 120° C. for 16 h when product and a small amount of hydrolysis were observed via lcms. The reaction mixture was diluted with DCM (150 mL), added to a separatory funnel, and washed with saturated aq. NaHCO3 (3×100 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 100% DCM to 2% 2 M NH3 in MeOH/DCM to give 1-(2-methyl-3-((2-methyl-4-(methylsulfonyl)butan-2-yl)amino)quinoxalin-5-yl)ethanone (338c, 513 mg, 1.47 mmol, 100% yield) as a red oil contaminated with NMP. 1H NMR (400 MHz, CDCl3) δ ppm 1.56 (s, 6H) 2.56 (s, 3H) 2.62-2.68 (m, 2H) 2.78 (s, 3H) 2.83 (s, 3H) 2.94-3.01 (m, 2H) 4.82 (s, 1H) 7.40 (dd, J=8.12, 7.34 Hz, 1H) 7.70 (dd, J=7.34, 1.47 Hz, 1H) 7.92 (dd, J=8.12, 1.47 Hz, 1H). MS (ESI, pos. ion) m/z: 350.2 (M+1).

1. customa small amount of hydrolysis
2. additionadded to a separatory funnel
3. washwashed with saturated aq. NaHCO3 (3×100 mL)
4. customthe organic layer was separated
5. dry with materialdried over Na2SO4
6. concentrationconcentrated
7. customwas purified