Abstrakt

Microwave assisted one-pot regioselective synthesis of 3,5-arylated pyrazoles from 2,3-dibromo-1,3-diarylpropan-1-ones using amberlite IR-120

Nosrat O.Mahmoodi, Manouchehr Mamaghani, Abbas Azimi Roshan, Hassan Ghasemnejad-Bosra

An efficient and direct protocol for the preparation of 3,5-disubstituted pyrazoles, one-pot regioselective condensation reaction of 2,3-dibromo- 1,3-diarylpropan-1-ones with hydrazine derivatives via useful intermediate 4-bromo- 1,3- aryl 4,5-dihydro-1H-pyrazole in the presence of amberlite IR- 120 under thermal andmicrowave conditions inEtOHas solvent is described. In thismethod, several types of aromatic diarylpropan, containing electronwithdrawing groups as well as electron-donating groups, were rapidly converted to the corresponding pyrazoles in good to excellent yields. The thermal solvent-free and microwave green procedures offer advantages such as shorter reaction times, simple work-up, excellent yield, recovery and reusability of catalyst.