Solid-Supported Cyclocondensation of Arylglyoxal on Ribosylthiourea under Microwave Activation : A Novel and Efficient Synthesis of N-Glycosylated-2-thiohydantoins

Solid-supported, microwave-assisted efficient one-pot route to N-ribonucleosides of 2-thiohydantoin via reaction of ribosylthiourea and arylglyoxal has been developed. The strategy involves initial nucleophilic addition of ribosylthiourea on arylglyoxal which on subsequent intramolecular cyclocondensation produce thiohydantoin N-ribonucleoside. The protocol involves acidic Al2O3 as solid support and was accomplished efficiently with quantitative conversion of reactants into product.