Author(s): K. Mogilaiah* and Pradeep Kumar Challa
An efficient and convenient protocol for the transformation of 3-[2-(3-(2-naphthyl)[1,8]naphthyridin2-yl)ethanhydrazonyl]-2H-2-chromoenones(hydrazones) 4 to 1-[3-(2-naphthyl)[1,8]naphthyridin-2- yl]-3-(2-oxo-2H-3-chromenyl)-1H-4-pyrazole carbalde- hydes 5 is achieved under microwave irradiation utilizing POCl3-DMF over silica gel with high yields. The purity of the products is high. The process is environmentally benign and experimental procedure is very simple. The structural assignments to compounds 4 and 5 are based on their elemental analyses and spectral (IR, 1H NMR and MS) data. The compounds 5 have been screened for their antibacterial activity.