[N+:1]([C:4]1[CH:5]=[C:6]([CH:17]=[CH:18][CH:19]=1)[O:7][C:8]1[CH:9]=[CH:10][C:11](C(O)=O)=[N:12][CH:13]=1)([O-:3])=[O:2].C1(P([N:34]=[N+]=[N-])(C2C=CC=CC=2)=O)C=CC=CC=1.C(N(CC)CC)C>C(O)(C)(C)C>[N+:1]([C:4]1[CH:5]=[C:6]([CH:17]=[CH:18][CH:19]=1)[O:7][C:8]1[CH:9]=[CH:10][C:11]([NH2:34])=[N:12][CH:13]=1)([O-:3])=[O:2]A mixture of 5-(3-nitrophenoxy)pyridine-2-carboxylic acid (10.4 g, 40.0 mmol), diphenylphosphoryl azide (10.8 mL, 50.0 mmol), triethylamine (6.92 mL, 50.0 mmol) and tert-butanol (200 mL) was stirred at room temperature for 3 hr, and then stirred with heating under reflux for 15 hr. The reaction mixture was concentrated under reduced pressure, trifluoroacetic acid (20 mL) was added to the residue, and the mixture was stirred at room temperature for 1 hr. The reaction mixture was concentrated under reduced pressure, 8N aqueous sodium hydroxide solution (70 mL) was added to the residue, and the mixture was stirred with heating under refluxing conditions for 3 hr. After extraction with ethyl acetate (×3), the organic layer was washed with saturated brine, dried over anhydrous magnesium sulfate and filtrated. The filtrate was concentrated under reduced pressure, and the residue was dried to give the title compound (5.80 g, 63%) as a white solid.
Loading…
