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

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Reaction Steps

This compound (245 mg, 46% yield) as a yellow foam was prepared according to the procedures described for 293b, using 2-bromo-1-(3-(tert-butylamino)-6-fluoro-2-methylquinoxalin-5-yl)ethanone (605) (366 mg, 1.03 mmol), (R)-ethyl 4-((tert-butoxycarbonyl)amino)-3-oxopentanoate (602) (322 mg, 1.24 mmol) and K2CO3 (357 mg, 2.58 mmol) in DMF (3.5 mL), 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-oxopentanoate (297a) (360 mg, 0.68 mmol, 65% yield, m/z 533.2 (ESI, +ve) (M+H)+) with NH4OAc (637 mg, 8.27 mmol) in 2 mL of EtOH and AcOH (1 mL). 1H NMR (400 MHz, CDCl3) δ ppm 7.61 (dd, J=9.00, 5.67 Hz, 1H), 7.32-7.36 (m, 1H), 7.20 (dd, J=11.54, 9.00 Hz, 1H), 6.97 (d, J=9.98 Hz, 1H), 5.09-5.21 (m, 1H), 4.96 (s, 1H), 4.36 (qd, J=7.14, 2.05 Hz, 2H), 2.54 (s, 3H), 1.72 (s, 9H), 1.53 (d, J=6.85 Hz, 3H), 1.36-1.46 (m, 12H). 19F NMR (376 MHz, CDCl3) δ ppm −107.07 (s, 1F). m/z 514.2 (ESI, +ve) (M+H)+.

Provenance & Evidence