Synthesis of novel acridine bis-sulfonamides with effective inhibitory activity against the carbonic anhydrase isoforms I, II, IX and XII

By using a multi component reaction system (MCR), nitro acridine sulfonamides were obtained from cyclic-1,3-diketones, 4-aminobenzene sulfonamide and aromatic aldehydes. Some novel acridine bis-sulfonamides 6a-l were then synthesized by the reaction between sulfonyl chlorides and the novel amino-acridine sulfonamides 5a and 5b, obtained by reduction of nitro-acridine sulfonamide derivatives 4a and 4b. The newly synthesized compounds were investigated as inhibitors of 4 human carbonic anhydrase isoforms (hCA, EC 4.2.1.1). Several of the compounds showed low micromolar inhibition against the medically relevant isoforms hCA I, II, IX, and XII.