Dimethylformamide → 3-Carbamoyl-4-methoxy-benzaldehyde

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

3-Bromo-anisaldehyde (8.0 g, 37.2 mmol) and copper cyanide (4.0 g, 44.67 mmol) were stirred in DMF (100 mL) at 150° C. for 16 h. To this was added an iron nitrate solution (20 g iron(III) nitrate, 6 mL concentrated HCl, 40 mL H2O), and the mixture stirred 10 min before it was allowed to cool to 23° C. The reaction was then diluted with H2O (200 mL) and extracted with CHCl3 (3×80 mL). organic layers were combined and solvents were removed, taking care to pump off the residual DMF. The brown-green residue was once again dissolved in CHCl3 (100 mL) and washed with 1 N HCl (50 mL) and brine (50 mL). The material was dried (Na2SO4), and solvent was removed to give the crude nitrile as a tan solid. The nitrile was stirred in concentrated H2SO4 (60 mL) at 100° C. for 1 h. The solution was cooled, poured into H2O (250 mL), and extracted with CHCl3 (8×50 mL). Organics were dried (Na2SO4) and concentrated. The resulting solid was recrystallized from methanol to give 2.98 g (45%) of 3-carbamoyl-4-methoxy-benzaldehyde 41 as a white solid. 1H NMR (CDCl3) δ 9.92 (1 H, s), 8.28 (1 , s), 8.00 (1 H, d, J=9.0 Hz), 7.74 (1 H, br s), 7.69 (1 H, br s), 7.33 (1 H, d, J=9.0 Hz), 3.98 (3 H, s); IR (KBr) 3399, 3183, 1676, 1589, 1433, 1262, 1204 cm−1. Anal. (C9H9NO3) C, H, N.

Herkunft & Nachweise