Microwave-promoted oxidation of 1,3,5-trisubstituted 4,5-dihydro-1H-pyrazoles by in-situ generation of NO+ and NO2+ respectively from sodium nitrite and sodium nitrate in acetic acid

Microwave-assisted aromatization of 1,3,5-trisubstituted 4,5-dihydro-1H-pyrazoles by in-situ generation of NO+ and NO2+ respectively from sodium nitrite and sodium nitrate in acetic acid has been carried out efficiently under mild reaction conditions in good to excellent yields.