An effective and mild oxidative aromatization of isoxazolines and 2-pyrazolines by trans-3,5-dihydroperoxy-3,5-dimethyl-1,2-dioxalane promoted by ammonium iodide in water/MeCN

Pyrazoles and isoxazoles are well-known important heterocyclic compounds that due to their participation in the structure of many drugs are very important. Pyrazoles and isoxzaloes can be prepared by oxidation of pyrazolines and isoxazolines respectively. In this work, trans-3,5-dihydroperoxy-3,5-dimethyl-1,2-dioxalane (DHPDMDO)/NH4I has been used as a new, powerful, nearly green, effective and inexpensive oxidant for oxidative aromatization of isoxazolines and 2-pyrazolines to corresponding isoxazoles and 2-pyrazoles in the presence of catalytic amount of acetic acid at room temperature in water/MeCN within short reaction time. All products obtained in high yields and good purity by aqueous work-up condition. More complex purification methods is not necessary in this methodology.