The anodic oxidation of caffeine and theophylline has been carried out at a controlled potential in a one compartment cell using glassy-carbon as the anode, platinum as the cathode and glacial acetic acid/sodium acetate as solvent-supporting-electrolyte (SSE). The oxidation of caffeine yields 1, 3,8-trimethyl-1,3,6,8-tetrazaspiro[4.4]nonane-2,4,7,9-tetrone and (4-acetoxy-1,3,7-trimethyl-2,6,8-trioxo-9H-purin-5-yl) acetate. Despite of the different structure, the oxidation of theophylline leads only to the same spiro compound 1, 3,8-trimethyl-1,3,6,8-tetrazaspiro [4.4]nonane-2,4,7,9-tetrone as in the case of caffeine. The structure of both compounds is described and the reaction mechanism is discussed.

The anodic oxidation of caffeine at a controlled potential with a glassy‐carbon anode and a platinum cathode with glacial acetic acid/sodium acetate electrolyte yields a spiro compound (III) and purinyl acetate (IV).