Magnetic base catalysts for the chemical fixation of carbon dioxide to quinazoline-2,4(1H,3H)-diones

Abstract

Organic superbase-functionalized magnetic Fe₃O₄ was investigated to catalyze the fixation of CO₂ with 2-aminobenzonitriles, resulting in the synthesis of quinazoline-2,4(1H,3H)-diones. After optimization of various reaction parameters such as reaction time, solvent, temperature and CO₂ pressure, 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD)-functionalized Fe₃O₄ was proven to be an efficient and recyclable magnetic heterogeneous catalyst for the synthesis of various quinazoline-2,4(1H,3H)-diones in reasonable yields (66–93%), and it could be recovered using an external magnetic field.