反应详情

A solution of Example 1E (0.4 g, 1.56 mmol) and diphenyl cyanocarbonimidate (0.372 g, 1.56 mmol) in DMF (10 mL) was heated to 90° C. for 2 days, cooled to room temperature, quenched with water, and filtered. The filter cake was suspended in ethanol and filtered. The filtrate was concentrated and purified by flash column chromatography on silica gel with 5 to 8% methanol/dichloromethane to provide the desired product (150 mg). MS(ESI(+)) m/e 401(M+H)+; 1H NMR (300 MHz, DMSO-d6) δ 11.06 (s, 1H); 8.27 (s, 1H); 7.67 (d, J=8.4 Hz, 2H); 7.50-7.43 (m, 4H); 7.36-7.29 (m, 3H); 2.29 (s, 3H).

1. customquenched with water
2. filtrationfiltered
3. filtrationfiltered
4. concentrationThe filtrate was concentrated
5. custompurified by flash column chromatography on silica gel with 5 to 8% methanol/dichloromethane