反应详情

In a 25 mL round bottom flask 4-nitro 1,2-phenylenediamine (300 mg, 1.96 mmol), and 4a (330 mg, 979 mmol) (see Example 2 for synthesis of 4a) were combined in ethanol (10 mL). The stirred mixture was brought to reflux for 3 h during which a yellow precipitate formed. The mixture was then chilled in an ice bath, filtered, and the precipitate washed with cold ethanol to give 5b (340 mg, 88.7%) as a waxy shiny yellow solid; mp>300° C. 1H NMR (600 MHz, DMSO-d6) δ 7.97 (dd, J=2.7, 9.2, 1H), 7.86 (d, J=2.6, 1H), 7.37-7.32 (m, 2H), 7.28-7.24 (m, 4H), 7.05 (s, 1H), 6.75 (d, J=9.2, 1H), 6.65 (s, 2H), 3.35 (s, 3H), 3.21 (s, 3H). 13C NMR (151 MHz, DMSO-d6) δ 159.06, 151.66, 150.89, 135.01, 133.84, 130.38, 129.34, 129.02; 128.32, 127.38, 126.19, 126.05, 121.34, 114.31, 105.49, 102.98, 31.59, 27.46. MS (ES+) (m/z): [M+1]+ calculated for C20H18N5O4, 392.135880. found 392.03.

1. temperatureto reflux for 3 h during which a yellow precipitate
2. customformed
3. temperatureThe mixture was then chilled in an ice bath
4. filtrationfiltered
5. washthe precipitate washed with cold ethanol