Synthesis of 3-(Azolylmethylene)Chroman-4-ones via Addition of Indoles and N-Methylpyrrole to 3-(Polyfluoroacyl)Chromones

Reactions of 3-(polyfluoroacyl)chromones with indole and N-methylindole in refluxing pyridine and Nmethylpyrrole under solvent-free conditions proceed at the C(2) atom of the chromone system with pyrone ring opening and subsequent cyclization to 2-hydroxy-3-(indol-3-ylmethylene- or pyrrol-2-ylmethylene)-2-(polyfluoroalkyl)chroman- 4-ones in good yields. Treatment of these compounds with morpholine gives trans-indolyl(pyrrolyl)chalcones.