Sciencemadness Discussion Board

Glyoxylic acid synthesis - starting w/ oxalic :: w/o PbO2

deadrush - 29-12-2023 at 12:26

So i'd like to reduce oxalic acid to glyoxylic acid electrochemically but i have yet to aquire or successfully make PbO2 electrodes. Is there an alternative that would work?

Maurice VD 37 - 30-12-2023 at 07:55

Why do you want an alternative ? The usual way for making PbO2 is to take a lead electrode, and use it as anode in an electrolysis with another electrode as cathode, in a bath of sulfuric acid solution.

[Edited on 30-12-2023 by Maurice VD 37]

mysteriusbhoice - 1-1-2024 at 00:22

graphite works because this is a reduction reaction so using PbO2 which will oxidize the fk out of the molecule is generally not a necessity. Ir-Ta MMO also works and Pt also works. The cathode I assume cannot be PbO2 because it would reduce to Pb which btw is a very good reducing cathode.

clearly_not_atara - 1-1-2024 at 17:10

Maybe you could provide a source for this supposed reduction that you're planning to do so we could have the foggiest clue what you're talking about? You wouldn't normally care very much about the anode for a reduction, but lead is a preferred cathode for the reduction of oxalic acid to glyoxylic acid.

https://www.academia.edu/download/81769708/978-1-4419-6996-5...

solo - 1-1-2024 at 18:04

Reference Information


Glyoxylic acid: synthesis, isolation, and crystallization
M. A. Pozdniakov, I. V. Zhuk
Russian Chemical Bulletin, International Edition
Vol. 68, No. 3, pp. 472—479, March, 2019



Note
The review summarizes approaches, known from the literature, to the synthesis, isolation, and crystallization of glyoxylic acid (GA), which is an important component in fine organic synthesis and is widely used in pharmaceutical, food, and perfume industry. The review describes the research dealing with GA synthesis from aqueous solutions of glyoxal by catalytic, electro- chemical, and enzymatic methods and by ozonolysis of maleic acid in solution. Alternative methods for GA synthesis are considered, for example, from glycolic acid in the presence of glycolate oxidase, oxalic acid, ethyl alcohol, and from various halogenated acetic acid deriva- tives. Approaches to GA isolation from the products of synthesis depending on the starting compound are considered, including extraction with amines or alcohols, the use of cation or anion exchange resins at elevated temperatures, and precipitation as insoluble alkaline earth metal salts. Methods for GA crystallization using various experimental techniques are presented.
Key words: glyoxylic acid, glyoxal, maleic acid, glycolic acid, oxalic acid, heterogeneous catalysis, homogeneous catalysis, ozonolysis.

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solo - 2-1-2024 at 07:23

Reference Information on glyoxylic acid electrochemically

Tafel, Julius; Friedrichs, Gustav (1904). "Elektrolytische Reduction von Carbonsäuren und Carbonsäureestern in schwefelsaurer Lösung". Berichte der Deutschen Chemischen Gesellschaft. 37 (3): 3187–3191. doi:10.1002/cber.190403703116.

Cohen, Julius (1920). Practical Organic Chemistry 2nd Ed (PDF). London: Macmillan and Co. Limited. pp. 102–104.

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