[F:1][C:2]1[CH:3]=[C:4]([CH:7]=[CH:8][C:9]=1[F:10])[CH:5]=O.[N+:11]([CH3:14])([O-:13])=[O:12].C([O-])(=O)C.[NH4+].O>C(O)(=O)C>[F:10][C:9]1[CH:8]=[CH:7][C:4]([CH:5]=[CH:14][N+:11]([O-:13])=[O:12])=[CH:3][C:2]=1[F:1]A solution of 3,4-difluorobenzaldehyde (5.05 g), nitromethane (5.3 mL) and ammonium acetate (6.3 g) in glacial acetic acid (60 mL) is heated at 110° C. for 16 hours, allowed to cool and poured into water (300 mL). The solution is extracted with EtOAc (2×200 mL). The combined extract is washed with 10% NaHCO3, water and dried over sodium sulfate, filtered and evaporated in vacuo to afford 1,2-difluoro-4-(2-nitro-vinyl)benzene (4.2 g). MS: 198 (M+H); 1H NMR (300 MHz, CDCl3) □7.9 (1H, d, J=10 Hz); 7.5 (1H, d, 10 Hz); 7.3 (2H, m); 6.95-7.15 (1H, m).
Wird geladen…
