Solid-phase synthesis of substituted cinnolines by a Richter type cleavageprotocol

Starting from triazene bound ortho-halo arenes on a solid support, palladiu m-catalyzed alkynylations and subsequent cleavage reactions under acidic co nditions give rise to ortho-alkynylaryldiazonium salts, which in turn under go cyclization to afford substituted 4-halo- and 4-hydroxycinnolines in mod erate to good yields. The method is applicable to automated synthesis. (C) 1999 Elsevier Science Ltd. All rights reserved.