Efficient domino strategy for the synthesis of polyfunctionalized benzofuran-4(5H)-ones and cinnoline-4-carboxamides.

An efficient, three-component strategy for the improved synthesis of multifunctionalized 6,7-dihydrobenzofuran-4(5H)-ones under microwave irradiation in ethyl alcohol within short periods has been established. The synthesized benzofuran-4(5H)-ones have been readily converted into polyfunctionalized cinnoline-4-carboxamides by treating with hydrazine hydratein in the same solvent through a regioselective ring-opening of the furan. Tedious workup procedures can be avoided because of the direct precipitation of products from the reaction solution by water addition, thus rendering the two-steps process ecofriendly.