反应详情

To an argon-flushed flask containing a suspension 0.486 g (1.68 mmol) of 4'-hydroxy-4-biphenylyl benzoate in 10 ml of acetic acid at 10°-15° C., 0.345 ml of HNO3 (d: 1.41) was added dropwise (about a drop per min). Then the reaction mixture was vigorously stirred at the same temperature for 30 min. Water (40 ml ) was added and the mixture was again stirred for 30 min. The yellow precipitate was filtered, washed several times with water, dried and purified by flash chromatography on silica gel using dichloromethane/hexanes [65/35] as eluent to give 4'-hydroxy-3'-nitro-4-biphenylyl benzoate (compound 15, Scheme II) as a yellow solid (0:539 g, 96%). This material was recrystallized from ethanol to give product of mp. 163° C.; Rf [hexanes/dichloromethane 40/60]: 0.42; 1H NMR (300 MHz, CDCl3): δ7.25(d, 1H, J=8.7 Hz), 7.33(d, 2H, J=8.7 Hz), 7.50-7.70(m, 5H), 7.84(dd, 1H, J=2.7 Hz, J=8.7 Hz), 8.23 (d, 2H, J=7.2 Hz), 8.32(d, 1H, J=2.7 Hz), 10.60(s, 1H); 13C NMR (300 MHz, CDCl3): δ120.54, 122.45, 122.81, 127.85, 128.65, 129.33, 130.23, 133.04, 133.78 136.04, 136.22, 150.91, 154.44, 165.15; IR (CHCL3): 3250(broad), 3020, 1740, 1620, 1540, 1510, 1490, 1325, 1270, 1225, 1220, 1170, 1080, 1065, 1025, 1000, 850 cm-1 ; Mass spectrum, m/z(rel.intensity): 335(M+ 7), 105(100), 77(16).

1. customTo an argon-flushed flask
2. stirringthe mixture was again stirred for 30 min
3. filtrationThe yellow precipitate was filtered
4. washwashed several times with water
5. customdried
6. custompurified by flash chromatography on silica gel