反应详情

To a stirred mixture of methyl 2-bromo-5H-pyrrolo[2,3-b]pyrazine-7-carboxylate (0.24 g, 0.94 mmol) and K2CO3 (0.156 g, 1.13 mmol) in 10 mL of DMF was added chloromethyl pivalate (0.17 g, 1.13 mmol) drop-wise at room temperature. Then the mixture was stirred at room temperature for 16 hours. The mixture was then poured into 30 mL of water, extracted with ethyl acetate (90 mL). The organic phase was washed with brine (10 mL) and dried over Na2SO4 to give a crude product, which was purified by column chromatography (silica gel, 200-300 mesh, eluting with a mixture of ethyl acetate and petroleum ether (1:1, v/v) to give methyl 2-bromo-5-(pivaloyloxymethyl)-5H-pyrrolo[2,3-b]pyrazine-7-carboxylate (0.276 g, 79.5%) as a pale yellow solid. LCMS: (M+H)+=370; 1H NMR (300 MHz, CDCl3): δ 8.42 (s, 1H), 8.38 (s, 1H), 6.21 (s, 2H), 3.96 (s, 3H), 1.15 (s, 9H).

1. extractionextracted with ethyl acetate (90 mL)
2. washThe organic phase was washed with brine (10 mL)
3. dry with materialdried over Na2SO4
4. customto give a crude product, which
5. customwas purified by column chromatography (silica gel, 200-300 mesh
6. washeluting with a mixture of ethyl acetate and petroleum ether (1:1