5-Formylsalicylic acid

Chemical Properties

light beige fine crystalline powder

Uses

5-Formylsalicylic Acid is used as a selective phase for the extraction of iron(III) in silica gel. It is also used in preparation of styrylquinolines as potent HIV-1 integrase inhibitors that block HIV-1 replication in CEM cells.

Definition

ChEBI: 5-formylsalicylic acid is a monohydroxybenzoic acid in which a benzoic acid nucleus is substituted at positions 2 and 5 by a formyl group and an hydroxy group respectively. It is a member of benzaldehydes, a monohydroxybenzoic acid and a member of phenols. It is functionally related to a salicylic acid.

Synthesis

General procedure for the synthesis of 5-formyl-2-hydroxybenzoic acid from 5-methylsalicylic acid: a mixture of the substrate 5-methylsalicylic acid (1 mmol), cobalt salt (n1 mol%), and NaOH (n2 eq.) in ethylene glycol (5 mL) was reacted with oxygen (1 atm) with stirring for 8 hours at 80 °C. Upon completion of the reaction, hydrochloric acid (10 mL, 2%) and methyl tert-butyl ether (MTBE, 10 mL) were added sequentially to the reaction mixture. The organic layer was separated and the aqueous phase was further extracted with MTBE (10 mL x 2). The organic phases were combined, dried with anhydrous sodium sulfate and concentrated to give the residue. The residue was purified by silica gel column chromatography (eluent: petroleum ether/ethyl acetate, 10/1) to afford the target product 5-formyl-2-hydroxybenzoic acid.

References

[1] Tetrahedron Letters, 2014, vol. 55, # 8, p. 1406 - 1411
[2] Molecular Catalysis, 2018, vol. 453, p. 121 - 131