Electrochemical Synthesis of 3-(Sulfonyl)quinol-4-ones from o -Alkynyl- N -(formyl)anilides and Sulfinates.

Electrolysis of o -alkynyl- N -(formyl)anilides and sodium sulfinates on graphite electrodes delivers biologically sound 3-(sulfonyl)quinol-4-ones with moderate to good yields. The reaction is carried out in an undivided cell in the presence of silver(I) oxide with potassium iodide or sodium tetrafluoroborate as the supporting electrolyte. The reaction tolerates variously substituted anilides as well as aryl and alkyl sulfinates. The transformation proceeds as a domino sequence of oxysulfonylation and cyclocondensation steps.