Design, Synthesis and Cu²⁺ Recognition of β-Diketoacid and Quinoxalone Derivatives Bearing Caffeoyl or Galloyl Moieties Linked by Arylamide as Potential HIV Integrase Inhibitors

An efficient procedure for the synthesis of caffeoyl- and galloyl-containing β-diketoacid derivatives linked by arylamide was reported by, in the key step, dissolving the corresponding phenyl methyl ketone in THF/DME in the presence of NaOMe as base and dimethyl oxalate as oxalylation reagent, and then separating the sodium ketoenolate ester. The resulting β-diketoacids underwent further condensation reaction with o-phenylenediamine to generate quinoxalone derivatives in good yield, rather than 2-benzimidazol. The preliminary ion binding properties of quinoxalone derivatives were also investigated. UV-Vis spectra showed that these compounds could selectively recognize Cu²⁺ ion in ethanol and form a 1:2 complex.