Synthesis of 10,10-Dioxo-10H-10λ6-phenoxathiine-2,8-dicarboxamides

Abstract

New carboxamides and sulfonamides containing alkyl and heterocyclic fragments were synthesized on the basis of 2-arylaminopyrimidine derivatives, N-methylpiperazine, and morpholine and 4-nitro-10,10-dioxo-10H-10λ⁶-phenoxathiine-2,8-dicarboxylic acid. The latter was obtained by intramolecular cyclization of 4-[4-carboxy-2-(chlorosulfonyl)phenoxy]-3-nitrobenzoic acid by the action of chlorosulfonic acid. The reactivity of 10,10-dioxo-10H-10λ⁶-phenoxathiine-2,8-dicarbonyl chlorides in the acylation of amines is discussed.