Sciencemadness Discussion Board

Hydroquinone from Phenol

bmays - 9-11-2016 at 00:01

I read H2O2 in presence of acid produces catechol and hydroquinone. However H2O2 also oxidizes hydroquione to benzoquinone.

I have tried sodium dichomate + sulfuric acid. Low yeilds likely due to poor extraction of benzoquinone from aqueous layer. Turns very black. Not idea.

Maybe oxone? But it will oxidize the 1,2 positions is the problem, so will H2O2 without acid. Maybe manganese dioxide?

Could someone give me some pointers? I couldn't find much info on sciencemadness or the net in general in regards to this. thanks

edit: found this video

[Edited on 10-11-2016 by bmays]

Aqua-regia - 10-11-2016 at 05:13

This video just tutorial. I think this is not a way to form hydroquinone. If you need preparing hidroquinone try oxidising aniline with chromate instead phenol.
This procedure well documented, can find easy.

Aqua-regia - 10-11-2016 at 09:09

Phenol +H2O2:

A mixture of phenol (5 mmol) and Ti-superoxide catalyst (125 mg, 20% w/w) in acetic acid (5 ml) was heated with stirring at 50-60° C. under inert atmosphere. To this reaction mixture was added aq. 50% H2O2 (20 mmol) drop wise over 15 min. and heated for 1 h. After this, water (5 ml) was added and the reaction mixture was heated to reflux for 7 h. The catalyst was recovered by simple filtration and 1,4-hydroquinone formed (61%) was separated by chromatographic purification.


bmays - 12-11-2016 at 22:27

Thanks Aqua-regia. The permanginate didn't work out. I will try H2O2, will have to concentrate it by vacuum distillation though. Could be some time, plus i don't have ti catayst nor titanium isopropoxide. I'll post results if i do any experiments.

Aqua-regia - 12-11-2016 at 23:20

Be careful with the vacuum concenration of H2O2. A little impurity of apparatus or sometime unexplained things can occuring a violent decomposition (explosion) of H2O2. Splittered glas parts can kill you. Face shild gloves etc!!