反应详情

温度

0 °C

tert-Butyllithium (1.7 M, 14.5 mL, 24.6 mmol, 2.39 equiv) was added to a solution of pyridin-2-yl-carbamic acid tert-butyl ester (5-1, 2.00 g, 10.3 mmol, 1 equiv) in ethyl ether (100 mL) at −78° C., and the resulting mixture was warmed to 0° C. and stirred for 1 h. N,N-Dimethylformamide (8.00 mL, 103 mmol, 10.0 equiv) was added with rapid stirring. The mixture was stirred at 0° C. for 10 min, then partitioned between half-saturated aqueous ammonium chloride solution (100 mL). The aqueous layer was further extracted with ethyl acetate (100 mL), and the combined organic layers were dried over sodium sulfate and concentrated. The residue was purified by flash column chromatography (40% ethyl acetate in hexanes) to afford (3-formyl-pyridin-2-yl)-carbamic acid tert-butyl ester (5-2) as a white solid.

1. stirringThe mixture was stirred at 0° C. for 10 min
2. custompartitioned between half-saturated aqueous ammonium chloride solution (100 mL)
3. extractionThe aqueous layer was further extracted with ethyl acetate (100 mL)
4. dry with materialthe combined organic layers were dried over sodium sulfate
5. concentrationconcentrated
6. customThe residue was purified by flash column chromatography (40% ethyl acetate in hexanes)