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PHILOU Zrealone
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| Quote: | Originally posted by Nicodem
Unfortunately it is not that easy. Me-CO-CCl<sub>2</sub>-CO-Me in the presence of hydroxide is just as easily cleaved to acetate and
Me-CO-CHCl<sub>2</sub> as CCl<sub>3</sub>-CO-R type of ketones are in the haloform reaction of methyl alkyl ketones. So, you
can not perchlorinate acetylacetone and similar beta-dicarbonyl compounds under such conditions - they cleave faster. |
So final products of perchlorination are only CHCl3 and H2CO3? 
PH Z (PHILOU Zrealone)
"Physic is all what never works; Chemistry is all what stinks and explodes!"-"Life that deadly disease, sexually transmitted."(W.Allen)
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theobromacacao
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Whilst it may not be strictly related to this thread, does anyone know how I can synthesise 1,10 phenathroline monohydrate (Ferroin) for use in a BZ
reaction? Alternatively, does anyone know where an individual (who is based in the UK) would be able to obtain any? Thank you to all in advance!
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Pixicious
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I thought malonic acid was derived from apple acid?
http://216.239.59.104/search?q=cache:k82cozVDy8wJ:www.ital.sp.gov.br/bj_old/brazilianjournal/ed_especial/10.pdf+apples+%22malonic+acid%22&hl=en&am
p;ct=clnk&cd=18&gl=uk
"...Dr Nitschke said the basic ingredients of the barbiturate were urea and malonic acid, found in apples. (me for a peaceful water-bed and some
zzzzs) ..."
Something I found.
[Edited on 28-2-2008 by Pixicious]
[Edited on 28-2-2008 by Pixicious]
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PHILOU Zrealone
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| Quote: | Originally posted by Pixicious
I thought malonic acid was derived from apple acid?
"...Dr Nitschke said the basic ingredients of the barbiturate were urea and malonic acid, found in apples. (me for a peaceful water-bed and some
zzzzs) ..."
Something I found.
[Edited on 28-2-2008 by Pixicious]
[Edited on 28-2-2008 by Pixicious] |
A bit confusing with those old grocery names:
-Malonic acid is propandioïc acid
-Maleic acid is cis-butenedioïc acid
-Malic acid is 2-hydroxy butandioïc acid
-Fumaric is trans-butendioïc acid
Malic refers to "Malus" in latin what means..."Apple" and for a not too obscure reason, without entering too much into religion aspects ... "Evil".
Maybe on a metaphoric/poetic view because Eve took the Apple from the knowledge tree to give it to Adam...it was the original sin, cause of all
troubles on Earth  --> Evil.
I suppose Evilic acid or Metaphoric acid would have had less succes than Malic and doomed by the Church 
PH Z (PHILOU Zrealone)
"Physic is all what never works; Chemistry is all what stinks and explodes!"-"Life that deadly disease, sexually transmitted."(W.Allen)
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Pixicious
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lol.
I was just wondering.
I know I am a bit of a newbie but I was wondering, is it true beetroot contains a calicum salt of malonic acid? If so why isn't this synthesis.
Pix
[Edited on 2-3-2008 by Pixicious]
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Formatik
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Malonic acid was discovered by the oxidation of malic acid in 1858. Scheele first isolated and described malic acid from apple juice in 1785 (it’s
not a good yield though  , apple juice contains 7g or more of malic acid per liter).
Nevertheless, if you want to be adventurous and see some ancient methods then it’s mentioned in Beilstein Vol. 1, p. 648 -649, and from supplement
1, p. 280: in addition to some others, well known or usual, malonic acid preparation:
By the oxidation of malic acid (Dessaignes, A. 107, 251) or raw L-(+)-lactic acid (Dossios, Z. 1866, 449) with K2Cr2O7.
Through the oxidation of allylene or propylene with a cold KMnO4 solution (Berthelot, A. Spl. 5, 97).
From hexabromomethylethylketone and fuming HNO3 (Demole, B. 11, 1714). CBr3.CO.CH2.CBr3 + O + 4 H2O = C3H4O4 + CO2 + 6 HBr.
By boiling barbituric acid with potash (Kali) (Bayer, A. 130, 143).
Boiling cyanoacetic acid with alkalis or HCl acid (Kolbe, A. 131, 349; H. Mueller, A. 131, 352).
From b-dichloroacrylic acid ester and silver oxide at 125 deg. (Wallach, Hunaeus, A. 193, 25). CCl2:CH.CO2.C2H5 + Ag2O + H2O = CO2H.CH2.CO2.C2H5 + 2
AgCl.
By boiling mucobromic acid C4H2Br2O3 with Ba(OH)2 (no reference given).
Preparation process from chloroacetic acid ethyl ester or chloroacetic acid with KCN is briefly described also (p. 648-9).
By the oxidation of d-quercitol (acorn sugar) with KMnO4 (Killiani, Schaefer, B. 29, 1763).
Through the addition of alkalis on acetonetricarboxylic ester (Willstaetter, B. 32, 1284).
If I can find the other triple in Beilstein, maybe there is more about its preparation.
A. = Liebig's Annalen der Chemie; A. Spl. (supplement).
B. = Berichte der Deutschen Chemischen Gesellschaft.
Z. = Zeitschrift für Chemie.
There is also supposed to be a significant amount of calcium malonate in red beet juice. I have no idea on how to extract it. The salts of malonic
acid are hardly soluble in water, except the alkali salts. Ca.C3H2O4 + 1 ¾ H2O is almost insoluble in cold water. 100 parts water solubilize at t °
= 0.2897 + 0,0.sub.2.423 544 1.t – 0,0.sub.4.233 510 3.t2 parts of the anhydrous salt. There are various hydrates of the calcium salt.
[Edited on 21-4-2008 by Schockwave]
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Magpie
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Malonate salts are indeed present in the juice of beets. Precipitation of Ca malonate is a problem for industrial refiners of sugar beets. It is
present at something around 2% in sugar beets IIRC. It would be an interesting challenge to extract malonate from beets IMO.
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garage chemist
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Here, it would be significantly cheaper to prepare malonic acid from (commercial) ethyl cyanoacetate than to buy it.
Crystalline malonic acid is expensive and does not find too much use outside the laboratory.
Even diethyl malonate is much cheaper than the free acid, and cyanoacetates are even cheaper.
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benzylchloride1
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Cohens Practical Organic Chemistry available in the Sciencemadness Library mentions that malonic acid can be prepared by oxidizing malic acid. Malic
acid is a common chemical that can be obtained cheaply from suppliers catering to home brewers. What type of oxidizing agent could oxidize malic acid
to malonic acid and carbon dioxide. Cohen's book dose not give any references to a procedure. This could be a useful procedure if it procedes in a
decent yield. Formatik upthread gives references to paper from the 1850's and 60's relating to this oxidation. My university does not have access to
many foreign chemistry journals even through inter library loan. If any one has copies of these articles it would be much appreciated to post them on
this thread. I have recently aquired some malic acid and would be interested in making malonic acid.
[Edited on 11-3-2009 by benzylchloride1]
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Sauron
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The usual suspects
Aqueous permanganate
Chromic-sulfuric acid
Nitric acid
I urge you to consult the literature, directly (Beilstein, the ACS search engine, Houben-Weyl, etc. Merck Index, Kirk-Othmer, Ullmann's.
Almost all the non-heterocyclic volumes of Beilstein are available in References. Much of Houben-Weyl as well. You really need to work on acquiring
your own library this way. It is time well spent.
Sic gorgeamus a los subjectatus nunc.
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benzylchloride1
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Sauron thank you for the advice. I have been slowly downloading material from the reference forum, but my internet connection is extremly slow, so it
has been a very tedious process. I have some permangante, dichromates and nitric acid in decent quantities. If you want to make carboxylic acids via
the malonic ester synthesis, 2,4-pentadione may work. Alkylate with your chosen halide. Dialkylated 2,4 pentadione could then be turned into the
disubstitued malonic acid via the haloform reaction. No enolate ion can form at the 3rd carbon because it is disubstituted. After acidfing the
reaction mixture, the dialkylated malonic acid could be isolated by extraction with an organic solvent. The malonic acid could decarboxylate during
the work up. I wonder if a Grignard reagent could be prepared from an active methylene halide, methylene chloride is out of the question because it is
used as a solvent in some Grignard reactions. The Grignard reagent could then be reacted with dry ice to make malonic acid. I do not know if
dibromomethane or diiodomethane can form grignard reagents. If sodium is availiable, an organosodium reagent could be eaisly prepared and reated with
dry ice to form malonic acid.
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Sauron
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2,4-pentanedione aka acetylacetone, is indeed a very useful reagent. But if I want to make anything via malonic ester synthesis I go buy diethyl
malonate. (I know this is a headache in the US, I am happily not in the US.)
Acetylacetone is better purchased than made, as it is rather cheap while the prep requires a LOT of expensive BF3-etherate as I recall. See Org.Syn.
for why DIY fails on economic grounds in this instance. Then look up the price of the end product versus the catalyst.
Per Acros
2,4-pentanedione $46 Kg MW 100 so $4.50/mol
Diethyl malonate $74 2.5 Kg MW 160 so $5 mol
I would not make acetylacetone into a malonic ester unless I had no other choice. We have not yet factored in cost of alkylating agent and the time
and effort.
[Edited on 12-3-2009 by Sauron]
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benzylchloride1
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I planning on obtaining some diethylmalonate soon. I get my 2,4-pentadione for free in small quantites from a friends company, so the cost is not an
issue, also I use small quantites, under 25 grams per synthesis usually. I have some BF3 etherate, but would rather not waste it. I mainly use
acetylacetone for making coordination complexes, but I plan on alkylating some to run a malonic ester type synthesis of a some a carboxylic acid, I
have not decided yet which acid I want to make. 2,4-pentadione is 2 times more expensive then diethyl malonate.
[Edited on 11-3-2009 by benzylchloride1]
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Sauron
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From what supplier is acetylacetone 2x as expensive as malonic ester?
On a molar basis they are 10% apart in price, and both $5 or less.
If you are using 25 g of the dione you are working on a 250 mmol scale as the molar mass is 100. So even if you were not getting it for free the cost
would be about $1.12. It's $45/Kg and a Kg is 10 mols.
Malonic ester (diethyl malonate) is $48/Kg or $73/2.5 Kg, As you can see it does not pay to buy the smaller packing. That is $30/Kg and a Kg is 6 mols
so $5/mol. $1.25 on your scale.
If you crunched the numbers for the 1 Kg bottle then yes it would be close to 2X. But that is not how to buy it. And no there is no similar economy in
the 2.5 Kg pack of the dione.
Sic gorgeamus a los subjectatus nunc.
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Magpie
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re: synthesis from malic acid. See page 1 of this thread. I didn't have much luck with the Dessaignes synthesis from the 1800's. Here's wishing
you better success!
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Globey
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Why not just fractionate the diethylmalonate from synthetic black cherry aroma oil (~25%), and de-esterify with NaOH?
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garage chemist
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Acetylacetone doesn't give malonate with NaOCl, not the slightest bit! Read the rest of this thread to find out why!
The methylene group of the acetylacetone gets chlorinated first, and then the molecule is cleaved into two C2 fragments and CHCl3.
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benzylchloride1
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The experiment that I am planning to conduct with the acetylacetone does not involve synthesizing malonic acid directly, but produces an alkylated
2,4-pentadione which then will be converted to an aliphatic acid using the haloform reaction. The haloform reaction will attack carbon 3 on the
pentadione moity, removing an acetic acid residue and the other methyl ketone will be converted into a carboxylic acid salt adding two carbons to the
chain. Example: 2,4-pentadione + 1 equivalent bromoethane + suitable base yields monoalkylated pentadione. Haloform reaction removes one of the
methyl groups attached to the ketone and also removes an acetic acis residue. After acidifing, butyric acid can be produced. I have not tried it, but
I plan to make a different acid due to butyric acid's awful smell. This is a possible way around the malonic ester synthesis of monocarboxylic acids.
[Edited on 12-3-2009 by benzylchloride1]
[Edited on 12-3-2009 by benzylchloride1]
Attachment: 2,4-pentadione synthesis of carboxylic acids.doc (17kB)
This file has been downloaded 1001 times
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Sauron
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Yes I understood all that from your previous posts.
But I see no advantage to that route as compared to the malonic ester synthesis of carboxylic acids itself, they are both active methylene compounds.
But, whatever floats your boat. The haloform is easy on a small scale, but does not scale up well.
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benzylchloride1
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Im not planning on scaling up the reaction, I would only want to make around 15 to 20 grams of product, I do not have much money to spend on chemicals
and since the 2,4-pentadione is free in 60 mL quantities this synthesis is currently the best route for me. I would love to have some malonic ester,
but that will have to wait. I used it once in organic chemistry lab for making barbituric acid; that was a fun synthesis, but they no longer run this
lab at the university because the pre medical students are way to impatient and want out of the lab in an hour. They run labs that used to be
professor conducted demonstations instead of fascinating labs like the malonic ester synthesis.
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Magpie
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| Quote: |
but they no longer run this lab at the university because the pre medical students are way to impatient and want out of the lab in an hour.
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Who accredits the pre-med curriculum? The students? Perhaps the students would just like to have their medical degrees mailed to them. Then they
wouldn't even have to spend an hour in the lab. 
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JohnWW
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| Quote: | Originally posted by Magpie
| Quote: | | they no longer run this lab at the university because the pre medical students are way to impatient and want out of the lab in an hour.
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Who accredits the pre-med curriculum? The students? Perhaps the students would just like to have their medical degrees mailed to them. Then they
wouldn't even have to spend an hour in the lab. |
That does not surprise me - in my experience, medical students, including pre-meds, are arrogant and self-centered beyond belief, because of the
inflated self-importance that becoming a medical doctor seems to give them. This may also be partly due to the fact that nearly all of them are highly
privileged, being from very wealthy and indulgent families, of which many are an only child, with most of them being the children of medical doctors
or dentists or of pharmacists who own their own retail shops.
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Sauron
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John, I know quite a number of MDs who did not come from money, were not only children, and if they had a doctor in the family it was an uncle or aunt
rather than a parent.
The children of MDs that I went to school with that I can recall went into unrelated fields.
I know radiologists, opthalmic surgeons, internists, psychiatrists, othopedic surgeons, oncologists, pathologists, and the whole panoply and I see
nothing to support your comments.
Sic gorgeamus a los subjectatus nunc.
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benzylchloride1
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I have a possible solution to the unavailability of diethyl malonate. If sodium metal can be obtained or high purity sodium ethoxide from the
equillibrium between ethanol and sodium hydroxide via Nicodem's method. Vogel and Organic synthesis describe a synthesis of ethyl phenylmalonate from
diethyloxalate and ethyl phenyacetate. The reaction produces ethyl phenyloxaloacetate which is then heated to about 150 C under vacuum causing it to
eliminate carbon monoxide and results in the formation of ethyl phenylmalonate. Perhaps this can be applied to ethyl acetate, isolating the ethyl
oxaloacetate which is usually sold as the sodium salt due to its instability, heating the ethyloxaloacetate to produce the diethyl malonate. I am
planning on trying this using first sodium ethoxide produced from sodium metal to see if this route is feasible before trying the equillibriation
method of making sodium ethoxide. Hopefully, more members will test the equillibriation procedure and work out an good high yielding method.
Another intriguing and exciting possibility, malic acid could be esterified with ethanol to produce diethyl malate, which could then be oxidized under
controlled conditions in a non-aqueous solvent, acetone, to produce diethyl oxaloacetate. This could be isolated and decarboxylated to form diethyl
malonate or may even decarboxylate during the oxidation, forming diethyl malonate. This is pure conjecture, but may be the answer to this problem.
[Edited on 27-1-2010 by benzylchloride1]
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Theophrastus_2
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Dunno if anyone else posted something like this, as there has been some stuff on dialkylated diones, but a longer (but maybe...?) simpler route would
be to perform a crossed aldol reaction between acetone and another readily available aldehyde (ie. benzaldehyde). In the case of my example, this
would form benzalacetone. From here, reduction of the central carbonyl would produce something like 1,5 diphenyl penta 2,4 diene. Cleaving the double
bonds with a common reagent like potassium permanganate would produce malonic acid and benzoic acid, which can be easily filtered off.
Pros: Aldol reaction is a very simple procedure
Potassium permanganate is quite available
Cons: The intrinsic problem is that the chosen procedure for the reduction of the central carbonyl would have to be selective, so as to keep the
double bonds intact while reducing the central carbonyl. I have absolutely no idea of how this might be done. Thoughts? And perhaps some references
for a means of reduction...
Attachment: Malonic Acid.sk2 (9kB)
This file has been downloaded 1040 times
Another means might be to cleave the benzalacetone directly to produce oxamalonic acid. Again, reduction is the problem, having to selectively reduce
the central carbonyl, and keeping the carboxylic acid carbonyl, as is.
[Edited on 1-2-2010 by Theophrastus_2]
[Edited on 1-2-2010 by Theophrastus_2]
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