反应详情

温度

50 °C

To a solution of B4 (10.07 g, 54.37 mmol) in dry pyridine (21.90 mL, 271.82 mmol) was added a solution of 4-nitrobenzoyl chloride (10.09 g, 54.37 mmol) in dry dioxane (100 mL), and the resulting mixture was heated at 50° C. for 2 h. After this time, the reaction mixture was cooled to room temperature and basified by addition of aqueous NH3. The resulting precipitate was collected by filtration to give a first batch of amide B5 (3.47 g, 19%) as an amorphous orange-yellow solid. The filtrate was extracted with EtOAc (×4), and the combined organic extracts were washed with brine, and then evaporated to dryness to give a mixture of B4 and B5 (ca. 1:1 by 1H NMR). Re-treatment of this mixture with 4-nitrobenzoyl chloride at 50° C. for 12 h gave a further 4 g of B5; 1H NMR [(CD3)2SO]: δ 6.86 (dd, J=4.82, 1.60 Hz, 2H, ArH), 7.21 (dt, J=9.86, 5.02, 3.00 Hz, 2H, ArH), 7.76 (d, J=8.84, 2H, ArH), 8.18 (m, 4H, ArH), 8.37 (ddd, J=9, 23, 4.33, 2.34 Hz, 2H, ArH), 8.73 (s, 1H, ArNHAr), 10.52 (s, 1H, ArC(O)NHAr). LCMS (APCl+): 335 (100%).

1. temperatureAfter this time, the reaction mixture was cooled to room temperature
2. filtrationThe resulting precipitate was collected by filtration