反应详情

To a solution of Example 220B (98 mg, 0.404 mmol) in tetrahydrofuran (1 mL) was added potassium t-butoxide (63.5 mg, 0.566 mmol) followed by addition of 2-bromo-5-cyclopropylpyrazine (Combi-Phos Inc) (89 mg, 0.445 mmol). The reaction mixture was stirred at room temperature for 24 hours. The mixture was diluted with water and extracted with ethyl acetate (2×20 mL). Volatiles were removed with a stream of nitrogen. The residue was chromatographed on a 12 g SiO2 column eluted with 5% ethyl acetate/hexanes for 3 minutes and then with a gradient to 100% ethyl acetate over 20 minutes. The title compound (87 mg, 0.241 mmol, 59.7% yield) was isolated as a colorless oil. 1H NMR (400 MHz, DMSO-d6) 8 ppm 8.09 (d, J=1.3 Hz, 1H), 8.06 (d, J=1.3 Hz, 1H), 5.44-5.39 (m, 1H), 4.12-4.04 (m, 1H), 3.71 (dd, J=12.4, 5.3 Hz, 1H), 3.64 (d, J=12.3 Hz, 1H), 3.57 (dd, J=12.4, 4.6 Hz, 1H), 3.39 (dd, J=12.4, 3.2 Hz, 1H), 2.30-2.06 (m, 3H), 1.41 (s, 9H), 0.97-0.90 (m, 2H), 0.87-0.81 (m, 2H).

1. extractionextracted with ethyl acetate (2×20 mL)
2. customVolatiles were removed with a stream of nitrogen
3. customThe residue was chromatographed on a 12 g SiO2 column
4. washeluted with 5% ethyl acetate/hexanes for 3 minutes
5. waitwith a gradient to 100% ethyl acetate over 20 minutes