C[C:2]1[CH:9]=[C:8]([OH:10])[CH:7]=[CH:6][C:3]=1[CH:4]=O.[N+:11]([CH3:14])([O-:13])=[O:12].[C:15]([O-])(=O)C.[NH4+]>C(O)(=O)C>[CH3:15][C:9]1[CH:2]=[C:3]([CH:4]=[CH:14][N+:11]([O-:13])=[O:12])[CH:6]=[CH:7][C:8]=1[OH:10]The 2-methyl-4-hydroxy-benzaldehyde (980 mg, 6.3 mmol), nitromethane (2.0 mL, 37.7 mmol) and ammonium acetate (1.9 g, 25.1 mmol) were dissolved in acetic acid (9 mL) and the reaction heated at 110° C. for 2 h. The reaction is concentrated under reduced pressure and the residue partitioned between ether and water. Separate the layers and dry with Na2SO4, filter and concentrate under reduced pressure. Purify the crude by flash chromatography (eluent: EtOAc/hexane 20/80 and 30/70) afforded the title compound (1.0 g). 1H-NMR (CDCl3, 200 MHz): 7.94 (d, 1H, J=13.4 Hz), 7.50 (d, 1H, J=13.6 Hz), 7.34-7.27 (m, 2H), 6.82 (d, 1H, J=8.1 Hz), 2.28 (s, 3H).
Wird geladen…
