Dimethylformamide → 6-Methoxy-5-formyl-2-naphthoic acid methyl ester

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of 6-methoxy-2-naphthoic acid methyl ester (10.3 g, 47.6 mmol) in DMF (36.9 mL, 476 mmol) at 5° C. was added POCl3 (44.4 mL, 476 mmol) dropwise. The reaction mixture was heated to 80° C. After 2 days at this temperature, the reaction was poured into ice/H2O (400 mL). The solution was made basic with addition of solid Na2CO3. The resulting mixture was extracted with EtOAc (2×400 mL). The organic layer was washed with brine (80 mL) and dried (MgSO4). After concentration, the residue was recrystallized from MeOH:H2O to afford the product (7.30 g, 63%) as a solid; 1H NMR (DMSO-d6) δ3.91 (s, 3H), 4.11 (s, 3H), 7.72 (d, J=9.3 Hz, 1H), 8.10 (dd, J=2.0, 9.0 Hz, 1H), 8.53 (d, J=9.2 Hz, 1H), 8.66 (d, J=1.8 Hz, 1H), 9.17 (d, J=9.0 Hz, 1H), 10.76 (s, 1H).

Provenance & Evidence