Aryl diketo acid derivatives are one of the most promising HIV-1 integrase（IN） inhibitors. With a view to substitute the critical diketo acid pharmacophore with the diketo benzimidazole unit, the coupling reaction of compound 4 with o-phenylenediamine was carried out. However, the reaction product, compound 5, was confirmed to be 3-{ [ 3- （phenylsulfonamido） benzoyl] methylidene t -3,4-dihydroquinoxaline-2 （1H） -one rather than the 2-benzimidazole derivative by using X-ray diffraction. Owing to its low solubility in water, the evaluation of the anti-HIV IN activity of the synthesized compound 5 could not be carried out. Consequently, the ion-binding properties of compound 5 in the absence of HIV-1 IN were investigated with UV-Vis spectroscopy in organic solvents. The results show that such a compound can selectively recognize Cu^2＋.
LI Xue-mei ZENG Cheng-chu NIU Li-ting YAN Hong ZHENG Da-wei ZHONG Ru-gang
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 Cu^2 ＋ ion in ethanol and form a 1 ： 2 complex.
Diketo acid derivatives are potent and selective HIV-1 integrase inhibitors. To investigate the detailed synthesis of those derivatives, a series of p/m-[p-（un）substituted phenylsulfonamido]phenyl β-diketo acid derivatives have been designed and synthesized. The quinoxalone derivatives as the potential bioisosteres of the biologically labile β-diketoacid pharmacophores have also been synthesized from reactions of the corresponding diketo acids with o-phenylenediamine. The structures of all diketo acid （ester） and quinoxalone derivatives were confirmed by 1^H NMR, 13^C NMR, IR, HRMS and/or MS （ESI）. X-ray crystallographic analysis of 11b demonstrates a similar arrangement of the side chain of quinoxalone derivatives with the parent diketoacids due to the intramolecular hydrogen bond （O…H-N） and the sp^2 hybridization configuration of the two nitrogen atoms of the quinoxalone ring.
The title compound 7-acetamido-5-chloro-8-（p-methyloxybenzenesulfonyloxy）-2- styrylquinoline 4 （C26H21ClN2O5S, Mr = 508.96） has been synthesized and characterized by 1HNMR, IR, ESI-MS and single-crystal X-ray diffraction techniques. The crystal belongs to orthorhombic, space group Pca21, with a = 7.920（3）, b = 10.672（5）, c = 28.008（12） A, V = 2367.3（17） A^3, Z = 4, Dc = 1.425 g/cm^3, μ = 0.290 mm^-1, F（000） = 1056, R = 0.0323 and wR = 0.0692 for 3895 unique reflections with 3127 observed ones （Ⅰ〉 2σ（Ⅰ））. X-ray analysis reveals that the styrylquinoline subunit adopts a coplanar conformation, where the benzene ring and quinoline are in trans configuration.
