Benignium
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Malic acid to malonic acid?
While browsing for information [on decarboxylating acetylsalicylic acid to yield phenylacetate that could then be mixed with calcium
acetate and subjected to dry distillation in an attempt to investigate whether benzyl methyl ketone could be produced that way] I
came across an article on TiO2-catalyzed solar degradation of acetylsalicylic acid. Along the degradation pathway were two subsequent stages that caught my
eye - one where malic acid is first oxidized to oxaloacetic acid and a second where this oxaloacetic acid was decarboxylated forming malonic acid and
carbon dioxide. I found an abstract from an article that claims it possible to oxidize malic acid to oxaloacetic acid in 60% yield using a PtBi/C catalyst and performing
the reaction at 25 degrees Celsius. I have not accessed the article.
What seems to be a major stumbling block is the decarboxylation of oxaloacetic acid which seems like it would form pyruvic acid and lawd knows what
else in addition to malonic acid. But perhaps it is still possible to isolate malonic acid.
I haven't investigated further, but I wanted to put this potential lead in writing so that I won't forget. Who knows, perhaps if I post here someone
can do me the courtesy of telling me I'm an idiot and to stop wasting my time because I'm not onto jack shit (same goes for the weird
meth thing). Or that a novel way of preparing malonic acid from malic acid may exist.
Preferably followed by an "And here's why:".
[Edited on 28-10-2020 by Benignium]
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Dr. Who
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The only thing I've been able to find on malic acid oxidation to malonic acid is this: https://gallica.bnf.fr/ark:/12148/bpt6k3004t/f76.item.langEN
Fair warning it's very old and in french, but the gist of it is this chemistry god threw a bunch of malic acid and chromic acid or potassium
dichromate (the sources are a bit fuzzy on which one the original paper says potassium dichromate, but other sources say chromic acid)in a pot and got
malonic acid out(although not very much). Page 76 and 77 are kinda the procedure but it's pretty lazy writing.
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Benignium
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I don't know any French so I used Google Translate. Very interesting. Thank you! This is the crude translation from pages 77-78:
ORGANIC CHEMISTRY. - Note on an arid obtained by the oxidation of acid
malique; - by IL DESSAIGNES.
"
I have made known under the name of tartronic acid an acid derived
by oxidation of tartaric acid, according to the following equation
"Malic acid, by a similar oxidation, would give an acid
Ce H8O8, according to the equation
This acid, identical or isomer to the nicotic acid of M. Barral, is the term which is lacking in the oxalic series between oxalic acid and succinic
acid; moreover, it would present with tartronic acid the
same composition ratios as succinic acid to malic acid.
It is this acid that I propose to temporarily name malonic acid,
until its identity with nicotic acid is proven.
It is the product of the oxidizing action of bichromate of potash on free malic acid, but it is only a secondary product and whose
The quantity is very small relative to the malic acid tested.
In a weakly concentrated solution of malic acid, I put a piece of
bichromate that I replace when its action is exhausted, and I also avoid heating the mixture by placing the capsule on the cold water.
contains. The liquor gives off carbonic acid, gives off the smell of acid
formic and becomes successively green, blue and finally brown. This last coloration is achieved when we have
used in dichromate a weight
almost equal to that of supposedly dry malic acid. I add water, I
heat moderately and I precipitate almost all the chromium oxide with a great excess of milk of lime. I withdraw from the precipitated mass, by
pressure
and by filtration, a greenish liquid which is precipitated by lead acetate.
The precipitate contains a notable quantity of lead chromate which i
separates with nitric acid, which, if it is not put in excess, only dissolves the organic salt. The liquor is filtered and three quarters saturated
with ammonia. The lead salt reproduces in white flakes which, in a few
hours, tighten a lot. This salt, washed, is decomposed by hydrogen
sulphide, and the liquor, filtered and concentrated at a very gentle heat, gives
crystalline layers surmounting a greenish or bluish syrup which crystallizes with difficulty and confusedly. This syrup is malic acid retaining
a little chromium oxide, and in the best-conducted preparations,
it is at least equal in weight to the crystals. The latter, drained on paper, are purified by crystallization.
The bimalate of lime is slowly oxidized by the bichromate of potash, but in this reaction I could not grasp the formation of the maloinic acid. On the
contrary, a large quantity of lime oxalate is produced there. The
lead peroxide also attacks the free malic acid when cold; but I do not have
not found the new acid in the reaction products.
Malonic acid occurs in the form of large rhombohedral crystals that have a lamellar structure. It is very water soluble and
in alcohol; it has a strongly acidic flavor. Heated to 100 degrees, it
loses about 12 per iao of interposed water, becoming opaque; at 150 degrees it melts at 150 degrees, it boils and gives off carbonic acid. he
distills without leaving any residue, and the condensed product is a mixture of acid
acetic and unaltered malonic acid, which can be easily separated by
second distillation I recognized acetic acid by its physical properties
and the salt which it forms with lead oxide. Its formation is explained by
the following equation
In the dried distillation of ammonia bimalonate, I obtained from
even ammonia acetate, carbonic acid and bicarbonate
ammonia.
"
Heated with concentrated sulfuric acid, the new acid decomposes with color. Its extended solution forms with lead acetate a
powder precipitate; with mercurous nitrate, a precipitate which blackens
if heated: it also reduces the gold chloride on boiling. His solution
concentrate does not precipitate potassium acetate; it precipitates the acetate of
lime and barite and silver nitrate. The precipitates dissolve if
add water. Silver salt does not turn black on boiling. Malonate
neutral ammonia precipitates salts of lime, barite, silver and
mercury. it discolors almost entirely the ferric chloride and does not prevent
no precipitation of iron oxide by ammonia added to the mixture
of the two salts. Neutral salts of potash and ammonia are deliquescent, but they crystallize in air dry. The acid salts of these same bases
readily crystallize into large, well-defined crystals. The neutral silver salt forms a crystalline powder, the barite salt of the
lime salt from small transparent needles.
As a side note, in the original post I mention phenyl acetate, an ester which I had confused with the calcium salt of phenylacetic acid, referred to
in the literature as phenylacetate. This has nothing to do with the actual topic but I felt the need to correct myself to avoid misinforming others.
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karlos³
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Quote: Originally posted by Benignium  | | While browsing for information [on decarboxylating acetylsalicylic acid to yield phenylacetate that could then be mixed with calcium
acetate and subjected to dry distillation in an attempt to investigate whether benzyl methyl ketone could be produced that way |
That does definitely not work.
You get a likewise named, but completely different molecule which is not a salt of phenylacetic acid.
Can't make P2P this way 
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clearly_not_atara
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In principle, periodate/periodic acid will convert malic acid to formylacetic acid by cleavage of the alpha-hydroxyacid moiety.
However, formylacetic acid is generally reported to be very unstable so it would also be hard to convert this to useful formylacetic esters or to
oxidize to malonic acid. But maybe there's some kind of trick to this.
[Edited on 04-20-1969 by clearly_not_atara]
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Benignium
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| Quote: Originally posted by karlos³ |
That does definitely not work.
You get a likewise named, but completely different molecule which is not a salt of phenylacetic acid.
Can't make P2P this way |
Thank you, what a pleasant response! I've opted to not pursue the dry distillation approach, instead I will attempt the phase transfer catalysed
Willgerodt-Kindler reaction from acetophenone with a few hopeful twists.
| Quote: Originally posted by clearly_not_atara | | ...formylacetic acid is generally reported to be very unstable so it would also be hard to convert this to useful formylacetic esters or to oxidize to
malonic acid. But maybe there's some kind of trick to this. |
This would be quite an undertaking.
I do not feel adequately equipped or, quite frankly, even adequately skilled to give it a go. Yet, at least. But for any future reference it is great
to know of this lead. Thank you!
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