guy - 8-11-2007 at 00:25
Is it possible to oxidize tartaric acid with some mild oxidizing agent to either glyoxal or oxalic acid?
I know sucrose can be turned into oxalic acid by HNO3 but with low yields.
On tartaric acid, it looks like the two hydroxyl groups can be oxidized to the ketone-carboxylic acids which should decarboxylate easily.
Sauron - 8-11-2007 at 01:03
Tartaric acid nitrates to a dinitro compound, which I suspect is energetic. See Org.Syn. preparation of imidazole.
So that is the wrong choice of reagent.
Eclectic - 8-11-2007 at 06:05
Also, tartaric acid is a mighty expensive precursor to make oxalic acid from. Sawdust and NaOH fusion will get you sodium oxalate.
guy - 8-11-2007 at 13:25
@Sauron,
I see...do you know of any good oxidizer that can oxidize it to oxalic acid that will not also oxidize oxalic acid?
@Eclectic
How good is the yield for this method? Considering how cheap this would be, I would say 10% is a good yield.
Eclectic - 8-11-2007 at 14:05
Check some of the really old books from the 1800's...
Also, you could just buy it as a wood bleaching product.
[Edited on 11-8-2007 by Eclectic]
not_important - 8-11-2007 at 16:42
Oxalic acid from sawdust is mention in this thread
http://www.sciencemadness.org/talk/viewthread.php?tid=8912
I think I have the full PDFs of several articles on this, I goofed back in that thread and used the 1st page only version.
The method is a version of the oxidation of alcohols by oxygen in the presence of strong base, as I mention in that thread NaOH and ethylene glycol
can be used in a similar fashion. The sawdust route needs good ventilation because of the charring wood fumes, and care needs to be taken when
working up the strong lye solution to recover the oxalate. Some acetate and formate can be obtained as well when using sawdust.
I should add that there was a fair amount of research done on this in the 1930s through WW-II. It was after then that the CO + NaOH => sodium
formate, sodium formate + heat => sodium oxalate route became the common method of production.
[Edited on 9-11-2007 by not_important]
Sauron - 8-11-2007 at 18:24
Ullmann's says the main industrial methods of oxalic acid production are
- oxidation of carbohydrates (sugars, starchs) w/nitric acid and recycling the NOx produced.
- oxidation of ethylene glycol
- from carbon monoxide
- oxidation of propane.
On a lab scale you might consider the ethylene glycol oxidation, as someone already suggested. Tartaric acid is uneconomical.
guy - 8-11-2007 at 21:04
Ok Thanks. Ethylene glycol is easy to get.
Alkaline KMnO4 can do the job...but I would like to know what other options there are.
I assume hypochlorous acid can also do the job? I know it works well on secondary alcohols such as cyclohexanol
Sauron - 8-11-2007 at 21:29
From Ullmann's
The oxidation of ethylene glycol with nitric acid is a one-step process. A flow chart is shown in Figure (2). An oxidizing mixture of 30 – 40 %
sulfuric acid and 20 – 25 % nitric acid is used. The oxidation is carried out in the presence of vanadium pentoxide and iron (III) salts, at 50 –
70 °C and atmospheric pressure. Only CO2 is formed as a byproduct.
Sounds easy enough to me.
Just out of curiosity why don't you just buy oxalic acid? It is cheap and readily available. It is even otc as a solid powder rust remover.