Synthesis
mixture of methyl 3-formylbenzoate (6.15 g, 37.46 mmol) in methanol (61.5 mL) and 2 M sodium hydroxide aqueous solution (37.5 mL, 75 mmol) was stirred at rt for 1 h. Thin-layer chromatography (petroleum ether: ethyl acetate = 1:1) showed that the reaction was complete. The reaction mixture was acidified to pH 2 with 80 mL of 1 M hydrochloric acid aqueous solution, and the resulting mixture was concentrated under vacuum. The residue was extracted three times with ethyl acetate, the bound organic layer was washed with brine, dried on anhydrous sodium sulfate, and the solvent was removed under vacuum to give 3-formylbenzoic acid. Yield: 5.59 g, 99.5%, to 3-carboxybenzaldehyde, a white solid.
Figure 3. Structural formula of 3-carboxybenzaldehyde
Uses
3-Formylbenzoic acid is used in the synthesis of bicyclic cis-2-azetidinone derivatives via Ugi 4-centre 3-component reaction, porphyrin capped with a steroidal superstructure bearing convergent hydroxy groups and 3-[(4-amino-1,2-dihydro-1-oxo-2-phenyl-1,2,4-triazolo[4,3-a]quinoxalin-6-yl)amino]methyl benzoic acid.
