反应详情

温度

20 °C

5-Nitropyridine-2-carboxylic acid 18 (1.06 g, 6.31 mmol) was refluxed in POCl3 (10 mL) for 1 h. (clear solution obtained), cooled to 20° C. and excess POCl3 was removed under vacuum. The resulting residue was dissolved in 1,4-dioxane ((20 mL) and added slowly to a suspension of 17 (1.44 g, 5.72 mmol) and N,N-diethylaniline (2.0 mL, 12.62 mmol) in 1,4-dioane (20 mL). The reaction mixture was stirred at 20° C. for 3 days. The resulting white precipitate was filtered and washed with more 1,4-dioxane. The solid was stirred in aqueous NH3 (20 mL) and the resulting red precipitate was filtered, washed with water and recrystallized from MeOH to give 20 (708 mg, 31%); mp (MeOH)>290° C.; 1H NMR ([(CD3)2SO] δ 10.74 (1 H, NH), 9.43 (dd, J=2.6, 0.5 Hz, 1 H, H-6), 8.96 (s, 1 H, NH), 8.81 (dd, J=8.6, 2.6 Hz, 1 H, H-4), 8.38 (dd, J=8.6, 0.6 Hz, 1 H, H-3), 7.81 (d, J=9.0 Hz, 2 H, H-2′ H-6′), 7.70 (d, J=9.1 Hz, 2 H, H-3′,5′), 6.09 (s, 2 H, NH2), 5.87 (s, 1 H, H-5″), 2.09 (s, 3 H, CH3); HRMS (FAB+) calc. for C17H16N7O3 (M+1) m/z 366.1315, found 366.1314; Anal. calc. for C17H15N7O3.0.25 MeOH: C, 55.5; H, 4.4: N, 26.3; found, C, 55.7; H, 4.5; N, 26.2%.

1. custom(clear solution obtained)
2. customexcess POCl3 was removed under vacuum
3. dissolutionThe resulting residue was dissolved in 1,4-dioxane ((20 mL)
4. filtrationThe resulting white precipitate was filtered
5. washwashed with more 1,4-dioxane
6. stirringThe solid was stirred in aqueous NH3 (20 mL)
7. filtrationthe resulting red precipitate was filtered
8. washwashed with water
9. customrecrystallized from MeOH