Potassium Carbonate → Ethyl 4-((tert-butoxycarbonyl)amino)-2-(2-(3-(tert-butylamino)-6-fluoro-2-methylquinoxalin-5-yl)-2-oxoethyl)-3-oxobutanoate

Participants

Reaction Steps

This compound (873 mg, 34% yield) as a yellow foam was prepared according to the procedure described for intermediate 293b, using 2-bromo-1-(3-(tert-butylamino)-6-fluoro-2-methylquinoxalin-5-yl)ethanone (605) (1.81 g, 5.11 mmol), ethyl 4-((tert-butoxycarbonyl)amino)-3-oxobutanoate (601) (1.50 g, 6.13 mmol) and K2CO3 (1.77 g, 12.77 mmol) in DMF (17 mL) was stirred at RT for 6 h, followed by the subsequent treatment of the resulting ethyl 4-((tert-butoxycarbonyl)amino)-2-(2-(3-(tert-butylamino)-6-fluoro-2-methylquinoxalin-5-yl)-2-oxoethyl)-3-oxobutanoate (296a) (1.43 g, 2.76 mmol, 54% yield, m/z (ESI, +ve) 519.2 (M+H)+) with NH4Oac (3.15 g, 40.9 mmol) in 12 mL of EtOH and AcOH (6 mL). 1H NMR (400 MHz, CDCl3) δ ppm 7.63 (dd, J=8.80, 5.67 Hz, 1H), 7.34 (dd, J=4.60, 2.45 Hz, 1H), 7.21 (dd, J=11.64, 8.90 Hz, 1H), 4.94 (s, 1H), 4.62 (d, J=5.87 Hz, 2H), 4.34 (q, J=7.24 Hz, 2H), 2.54 (s, 3H), 1.69 (s, 9H), 1.43 (s, 9H), 1.38-1.42 (m, 3H). 19F NMR (376 MHz, CDCl3) δ ppm −107.37 (s, 1F). m/z (ESI, +ve) 500.1 (M+H)+.

Provenance & Evidence