反应详情

温度

100 °C

A mixture of the title compound from Example 19 Step A (1.5 g, 5.4 mmol), di-tert-butyl hydrazine-1,2-dicarboxylate (1.375 g, 5.92 mmol), DPPF (360 mg, 0.65 mmol), Pd2 dba3 (0.4 g, 0.43 mmol), Cs2CO3 (1.90 g, 5.83 mmol) and 12 mL toluene was stirred at 100° C. After 20 h, the mixture was allowed to cool to ambient temperature, then purification by flash chromatography on silica gel using hexane-EtOAc (20:1 to 4:1 v/v) as mobile phase provided the title compound: LCMS m/z 375.6 (observed [M+H]+ for the ion corresponding to loss of one Boc group); 1H NMR (400 MHz, acetone-d6) δ 7.86 (d, J=2.1 Hz, 1H), 7.26 (dd, J=8.4, 2.1 Hz, 1H), 7.07 (d, J=8.4, 2.1 Hz, 1H), 3.93 (s, 3H), 2.31 (s, 3H), 1.54 (s, 9H), 1.47 (s, 9H).

1. temperatureto cool to ambient temperature
2. custompurification by flash chromatography on silica gel