Vicinal Benzo[b]thiophene-5,6-dicarboxaldehyde in Heterocyclic Synthesis: A Reagent for Fluorescence Determination of Amino Acids

Abstract

Benzo[ b]thiophene-5,6-dicarboxaldehyde reacts with dibenzyl ketone, thiodiacetic acid dimethyl ester, hydrazine, p-toluidine, p-aminoacetophenone and nitromethane to give the corresponding seven, six and five-membered rings condensed to benzo[ b]thiophene. Reaction of benzo[ b]thiophene-5,6-dicarboxaldehyde with p-toluidine in the presence of 2-mercaptoethanol gives highly fluorescent compounds. Also, benzo[ b]thiophene-5,6-dicarboxaldehyde was applied to fluorogenic reaction with some amino acids and the obtained data were compared with the reported data in the case of o-phthaldehyde. The synthesised compounds were characterised by their elemental analysis, IR, 1H NMR and mass spectrometry