Application of beta-oxodithioesters in domino and multicomponent reactions: facile route to dihydropyrimidines and coumarins.

A facile route to hitherto unknown 5-methylmercaptothiocarbonyl-4-aryl-3,4-dihydropyrimidin-2(1H)-ones and substituted 2H-chromene-2-thiones has been developed. SnCl(2)-catalyzed cyclocondensation of beta-oxodithioesters with a variety of readily accessible aldehydes and urea affords the dihydropyrimidinones. The methodology involves the three-component Biginelli reaction. On the other hand, substituted salicylaldehyde and beta-oxodithioesters reacted under the same condition to afford the substituted 2H-chromene-2-thiones in high yields.