Rapid synthesis of fully substituted arylideneisoxazol-5(4H)-one using zinc oxide nanoparticles

A straightforward, rapid, green, and efficient synthetic procedure has been introduced for easy access to the synthetically highly substituted arylideneisoxazol-5-(4H)-one products. A wide scope of the heterocyclic products was obtained via the three-component cyclocondensation of various aryl aldehydes, NH2OH center dot HCl, and beta-dicarbonyls by zinc oxide nanoparticles (ZnO NPs) as the catalyst. Optimizing the reaction conditions indicated that a relatively small amount of catalyst was required and arylideneisoxazol-5-(4H)-ones were obtained in very short reaction times. Purification of synthesized heterocyclic molecules was carried out with the help of simple filtration and crystallization from ethanol. In this method, exhausting and expensive chromatography methods were not used to purify the products, and the use of organic solvents was also avoided. In addition, this method is important from the point of view of green chemistry. The simplicity of the method, cost-effective catalyst, less time-consuming, mild reaction conditions, conducting experiments at room temperature, as well as recyclability and reusability of ZnO nano-catalyst are among other advantages of this powerful process.