4-Formylbenzoic acid → Tert-butyl {2-[(4-formylbenzoyl)amino]phenyl}carbamate

Participants

Reaction Conditions

Reaction Steps

To a suspension of 4-carboxybenzaldehyde (6 g, 40 mmol) in dichloromethane (10 mL) was added thionyl chloride (4.1 mL, 56 mmol, 1.4 eq), followed by DMF (1 dropwise. The mixture was refluxed for 4 hours and excess of thionyl chloride and DMF were removed under reduced pressure. To a solution of (2-aminophenyl)-carbamic acid tert-butyl ester (8.32 g, 40 mmol, 1 eq) in dichloromethane (80 mL), stirred at 0° C., was added a suspension of 4-formyl benzoyl chloride in dichloromethane (20 mL), followed by diisopropyl ethylamine (3.61 mL, 20 mmol, 1 eq). The mixture was stirred for 30 minutes at 0° C. then at room temperature for 30 minutes. The crude residue was diluted with dichloromethane (300 mL) and washed with water. The combined organic layers were dried (MgSO4), filtered and concentrated under vacuo. The crude residue was purified by column chromatography on silica gel (elution 20% ethyl acetate in hexane) to give 6.1 g (45% yield) of anilide 315. 1H NMR (CDCl3): δ 10.18 (s, 1H), 9.64 (brs, 1H), 8.20 (d, J=7.9 Hz, 2H), 8.06 (d, J=7.9 Hz, 2H), 7.96 (d, J=7.9 Hz, 1H), 7.28-7.38 (m, 1H), 7.24 (d, J=4.4 Hz, 1H), 6.84 (s, 1H), 6.81 (d, J=8.8 Hz, 1H), 1.58 (s, 9H).

Provenance & Evidence