Ultrasonic synthesis of substituted chromenes by utilizing potassium titanium oxalate

Abstract

Synthesis of substituted 2-amino-3-cyano-4-aryl-4H-chromenes, 4H-benzo[H] and 4H-benzo[F] chromenes by utilizing potassium titanium oxide oxalate dihydrate as a catalyst. It was observed that ultrasound-assisted method gave 92% yield in just 15 min at 40 kHz and 40 °C as against 3.5 h required to get 85% yield by conventional method at reflux temperature. Avoided the use of many hazardous catalysts and utilize simple, readily available and water soluble catalyst. Efficiency of catalyst was greater and removes easily from reaction medium. About 93% energy was saved during ultrasonic transformation over conventional method. Synthesized compounds show anti-bacterial activities with positive results to selected gram positive and gram negative bacteria. IR gives preliminary information to synthesized functional groups and NMR data confirms the structure of synthesized chromenes.