Ultrasonically Assisted Efficient and Green Protocol for the Synthesis of 4H-isoxazol-5-ones using Itaconic Acid as a Homogeneous and Reusable Organocatalyst

Background: Multicomponent reactions involve the simultaneous reaction of three or more components which deliver the product that incorporates the elements of all starting materials. A combination of multicomponent reaction and green solvents like water and the use of nonconventional energy sources like microwave or ultrasonication are important features of ideal green synthesis. Therefore, the design of a new multicomponent reaction and improvement of an already known multicomponent reaction with a green procedure has attracted the attention of the scientific community. Isoxazole derivatives are well known for their biological activities such as antifungal, analgesic, antitumor, antioxidant, antimicrobial, COX-2 inhibitory, anti-inflammatory, antiviral, and antimycobacterial. Objective: To develop a green methodology for the synthesis of 4H-isoxazol-5-ones derivatives. Result: Itaconic acid was used as a green catalyst for the synthesis of 4H-isoxazol-5-ones derivatives under conventional as well as ultrasound irradiation technique. Ultrasound irradiation condition requires less time for the completion of the reaction and also the yields were better. Methods: We have reported Itaconic acid as a green homogenous organocatalyst under ultrasound irradiation for the synthesis of 4H-isoxazol-5-ones derivatives. Conclusion: In conclusion, we have developed a green methodology for the synthesis of 4H-isoxazol-5-ones derivatives. Itaconic acid is used as an organocatalyst which is biodegradable and nonhazardous. Water is used as a green solvent. Ultrasonication is used as a non-conventional green energy source. Ambient reaction conditions are used to carry out transformation for multicomponent reaction. Metal-free, mineral acid-free synthesis are key features of the present protocol.