A facile & convenient route for the stereoselective synthesis of Z- isoxazol-5(4H)-ones derivatives catalysed by sodium acetate: Synthesis, multispectroscopic properties, crystal structure with DFT calculations, DNA-binding studies and molecular docking studies

Abstract

An efficient procedure for the one-pot synthesis of 4-arylmethylene-3- methylisoxazol-5-ones from ethyl acetoacetate, hydroxylamine hydrochloride, and various aromatic aldehydes using sodium acetate as a safe, clean, and green catalyst in ethanol is reported. This simple, synthetic and eco-friendly approach resulted in a remarkable improvement in the synthetic efficiency (90–95% yield), high purity, minimizing the production of chemical wastes without using highly toxic reagents for the synthesis and, more notably, it improved the selectivity for (Z)-isoxazol-5-ones derivatives. By performing DFT calculations, it was found that the (Z)-isomer of compound 4a is stabilized by 6.54 kcal mol−1 more than the (E)-isomer and The Z-isomer of 4g is also more stable, by 4.36 kcal mol−1. All of the compounds were tested for interaction study with ct-DNA. Compounds 4a and 4b shows the most effective binding affinity with ct-DNA in comparison of other synthesized compounds. The interaction studies of compound 4a and 4b with ct-DNA showed groove binding interaction (non-intercalation) with both compounds. On the other hand, compound 4a (K = 5.9 × 105 M−1) shows higher binding affinity to the ct-DNA than compound 4b (K = 4.5 × 105 M−1). The molecular modeling results illustrated that compound 4b strongly binds to groove of DNA by relative binding energy of docked structure −6.35 kcal mol−1.