Cellulose-SO3H: an efficient and biodegradable solid acid for the synthesis of quinazolin-4(1H)-ones

The condensation of 2-aminobenzamide with aldehydes or ketones has been achieved using cellulosesulfonic acid under mild reaction conditions to furnish 2,3-dihydroquinazolin-4(1H)-ones in good yields with a high selectivity. The use of biodegradable solid acid catalyst, cellulosesulfonic acid makes this method quite simple, more convenient, and practical. This catalyst was also found to be very active for the synthesis of hydroxyalkylquinazolin-4-ones from cyclic enol ethers.