反应详情

温度

50 °C

A mixture of 5-ethyl-2-nitroaniline (21) (1.38 g, 8.3 mmol) and cyanamide (1.40 g, 33.2 mmol) were mixed together at 100° C., cooled to 50° C., cHCl (15 mL) added carefully and the mixture heated at 100° C. for 4 h. The mixture was cooled to 50° C., 7.5 M NaOH solution added until the mixture was strongly basic and the mixture stirred at 100° C. for 3 h. The mixture was cooled, diluted with water (100 mL), filtered, washed with water (3×20 mL), washed with ether (3×5 mL) and dried. The residue was purified by chromatography, eluting with a gradient (0-10%) of MeOH/DCM, to give 1-oxide 22 (684 mg, 43%) as a yellow powder, mp (MeOH) 259-262° C.; 1H NMR [(CD3)2SO] δ 8.03 (d, J=8.8 Hz, 1 H, H-8), 7.31 (d, J=1.7 Hz, 1 H, H-5), 7.20-7.25 (m, 3 H, H-7, NH2), 2.72 (q, J=7.6 Hz, 2 H, CH2), 1.23 (t, J=7.6 Hz, 3 H, CH3); 13C NMR [(CD3)2SO] δ 160.3, 152.4, 149.0, 128.2, 125.6, 123.2, 119.6, 28.2, 14.5. Anal. calcd for C9H10N4O: C, 56.8; H, 5.3; N, 29.5. Found: C, 56.7; H, 5.1; N, 29.2%.

1. additionwere mixed together at 100° C.
2. temperaturethe mixture heated at 100° C. for 4 h
3. temperatureThe mixture was cooled to 50° C.
4. temperatureThe mixture was cooled
5. filtrationfiltered
6. washwashed with water (3×20 mL)
7. washwashed with ether (3×5 mL)
8. customdried
9. customThe residue was purified by chromatography
10. washeluting with a gradient (0-10%) of MeOH/DCM