Sciencemadness Discussion Board

Electrochemical oxidation of ethylbenzene to acetophenone

phendrol - 28-12-2012 at 08:23

I stumbled upon a pretty interesting patent lately. US 4459186, titled "Electrochemical oxidation of alkyl aromatic compounds". The authors claim that acetophenone can be prepared from ethylbenzene via a diketal, diester or a dihalide, depending on the nucleophile used (alkali oxides, esters or halides), by an electrolysis in an alcoholic solvent. Seems pretty straightforward and easy but the patent lacks some important information. There is no yield specified anywhere which combined with the fact that there can be made a lot of variations in the choice of solvent and nucleophile confuses a bit.

I'll experiment a bit with this method soon. I haven't got any anhudrous ethanol or methanol at the moment so my solvent of choice will be isopropyl alcohol. I'm still not sure about the cell. Not sure if it should be divided or one compartment.

killer_lapin - 28-12-2012 at 14:29

Exemple I
"...may have a surface area of about 50 square centimeter utilizing a copper cathode and a platinum anode, the electrode being place at a distance of about 13mm."

the distance is specified but no compartimentation is mentioned, it's probably a non-divided cell.

phendrol - 29-12-2012 at 01:02

"The electrochemical oxidation is effected in an electrochemical cell which may be a divided electrical cell using suitably chosen electrodes and an environmentally suitable anion expansion membrane or, if so desired, it may also be effected in a standard electrolytic cell which is not divided."

I would assume that a divided cell is better.

killer_lapin - 29-12-2012 at 15:38

There is formation of an intermediate wich i suppose is sensitive to reduction. Then yes divided cell should be better. Which material are you going to use for your diaphragm?