Tert-Butylamine → 8-bromo-N-(tert-butyl)-7-fluoro-3-methylquinoxalin-2-amine

関与物質

反応条件

反応手順

A mixture of 5-bromo-3-chloro-6-fluoro-2-methylquinoxaline (600) (5.00 g, 18.15 mmol) and tert-butylamine (Alfa-Aesar, Ward Hill, Ma) (9.62 mL, 91 mmol) in DMSO (50 mL) in a sealed tube was heated at 100° C. for 2 h. After cooling to RT, the mixture was diluted with EtOAc and saturated NaHCO3 (aq.). The layers were separated and the aq. layer was extracted with EtOAc (3×). The combined organic layers were washed with water and brine and dried over anhydrous Na2SO4, filtered and concentrated. The crude material was absorbed onto a plug of silica gel and purified by silica gel chromatography (0-20% EtOAc in hexanes) to provide 8-bromo-N-(tert-butyl)-7-fluoro-3-methylquinoxalin-2-amine (605a) (4.70 g, 15.06 mmol, 83% yield) as an orange solid. 1H NMR (400 MHz, CDCl3) δ ppm 7.71 (1H, dd, J=9.0, 5.7 Hz), 7.14 (1H, t, J=8.6 Hz), 4.82 (1H, br. s.), 2.51 (3H, s), 1.64 (9H, s). 19F NMR (376 MHz, CDCl3) δ ppm −103.85 (s, 1F). m/z (ESI, +ve) 312.0, 314.0 (M+H)+.

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