反应详情

To a solution of the product from step E (5.54 g, 12 mmol) in 30 mL of dichloromethane was added 13 mL of trifluoroacetic acid. The reaction mixture was stirred at ambient temperature for 16 h then was concentrated in vacuo and excess trifluoroacetic acid removed by azeotropic distillation with dichloromethane to provide the title compound as a white solid. 1H NMR (500 MHz, CDCl3) δ; 8.00 (d, J=8.2 Hz, 2H); 7.83 (d, J=1.8 Hz, 2H); 7.41 (d, J=1.9 Hz, 1H); 7.36 (d, J=8.3 Hz, 2H); 7.32 (s, 1H); 5.94 (s, 2H); 4.87 (s, 3H).

1. concentrationthen was concentrated in vacuo and excess trifluoroacetic acid
2. customremoved by azeotropic distillation with dichloromethane