Is there somebody that has synthesized propionic acid from chloroacetone (favorkii reaction)? I have proven with KOH it bases, solvent ethanol and to
boil. It has not worked. Before making other tests with other temperatures, if there is somebody that has synthesized propionic acid with favorkii
reaction or if with substratum one cannot make because polymerize too easily?Sauron - 10-11-2007 at 17:34
From Merck Index entry on Favorskii Rearrangement:
Detailed experimental procedure: D. W. Goheen, W. R. Vaughan, Org. Syn. coll. vol. 4, 594 (1963). Application to the synthesis of carboxylic acids: T.
Satoh et al., Bull. Chem. Soc. Japan 66, 2339 (1993). Applications to asymmetric synthesis: idem et al., Tetrahedron Letters 34, 4823 (1993); E. Lee,
C. H. Yoon, Chem. Commun. 1994, 479. Reviews: A. S. Kende, Org. React. 11, 261-316 (1960); P. J. Chenier, J. Chem. Ed. 55, 286 (1978); A. Baretta, B.
Waegill, "A Survey of Favorskii Rearrangement Mechanisms" in Reactive Intermediates, R. A. Abramovitch, Ed. (Plenum Press, New York, 1982) pp 527-58
The examples I recall seeing employed stronger bases than NaOH, such as alkoxides and the products were esters.
Is your purpose to explore the Favorskii or to obtain propionic acid?
If the latter I suggest you oxidize n-propyl alcohol.
This does not involve any nasty lachrymatory chloroacetone.
[Edited on 11-11-2007 by Sauron]Filemon - 10-11-2007 at 18:37
I have read is enough you on Favorskii rearrangement (wikipedia, Organic Syntheses, books, patents):
I have read abaout Favorskii rearrangement (wikipedia, Organic Syntheses, books, patents):
Many bases can be used. But its more used it is KOH and solvent alcohol. I have read in a patent that the good temperature of the reaction is 60º at
100ºC. But I suppose that it depends on the substratum. I have seen in other patents work to low temperatures (0ºC). I decide to prove chloroacetone
because it is easy to synthesize and the cheap and easy reagents of getting. I have planned to prove the reaction with other substratum but before I
have to synthesize other ketones. I have only acetone.Sauron - 10-11-2007 at 18:55
Patents are often deliberately vague, misleading and unreliable. At best they are suggestive. But never to be relied upon.
Wilkepedia is a joke.
KOH is indeed a stronger base than NaOH.
If I understand your post, you have not been able to make this reaction work, is that right? So my suggestion stands. Go back to the literature and
see if anyone ever made propionic acid this way and see what their conditions and reagents were.chemrox - 10-11-2007 at 22:28
Wikipedia is remarkably good for what it is but it is not a technical journal. Sometimes Merck will give you enough references to get good
information if you look them up. Sauron say patents are less than useful. My own experience is sometimes they are quite complete and accurate but as
he indicated they can leave out essentials. Many bees have had frustrating times following patents. It's instructive to know a synthesis well and
then look up its patent documents. As to propionic acid, its hard to follow your English.. consider getting some help with it. Propionic acid is
cheap and the Ca salt is common and cheaper still. Making it the way you're talking about would be a miserable exercise IMHO.Sauron - 10-11-2007 at 22:36
I think filemon is interested in the Favorskii rearrangement, and chloroacetone is just his idea of an easy and cheap substrate.vulture - 11-11-2007 at 02:29
Quote:
Wikipedia is remarkably good for what it is but it is not a technical journal.
Wikipedia can be excellent (see article on polythiophenes) but most of the time it is mediocre at best. If you must use it, check the references and
their credibility first. There's alot of original research and assumptions on wikipedia.WizardX - 11-11-2007 at 15:30
Lets assume the Favorskii Rearrangement does work for a minute.
The CH3-C(=O)-CH2Cl enolate cyclizes to a cyclopropanone intermediate, which then ring cleavage (ring opening) must occur for CH3CH2COOH
Think about!!??Sauron - 11-11-2007 at 15:51
Filemon may not have made a particularly sage exemplar.
In fact it would be interesting to prepare 2-chlorocyclobutane and see whether or not cyclopropylmethanol can be obtained from it via Favorskii
conditions.
Cyclopentylmethanol is certainly had from 2-chlorocyclohexanone. I would bet that cyclobutylmethanol is had from 2-chlorocylopentane.
Doubtless the answers are in the lit. Is there a Favrskii review in Org.Reactions, or Chem.Rev?leu - 11-11-2007 at 18:08
As has been said before by another member elsewhere, it would be a lot easier to react MEK with calcium hypochlorite getting propionic acid and
chloroform via the haloform reaction not_important - 11-11-2007 at 18:22
Favorskii on 2-chlorocyclohexanone gives ring contraction to the Cyclopentanecarboxylic acid. The rearrangement does go through the cyclopropanone
intermediate, both 1-Br and 3-Br MEK give the same isobutyric acid.
Named Organic Reactions has a chapter on the Favorskii rearrangement.Sauron - 11-11-2007 at 20:59
n_i, I already cited that procedure from Org.Syn. in the second post of this thread.
Unfortunately the other refernce that looks promising, from BullChem.Soc.Japan 1993, is not part of the BCSJ compilation I have which ends in 1991,
and it is anyone not Favorskii per se but a modification.
Likewise I obtained the JCE review article cited in that Merck snippet, and it is concerned with Favorskii application to bridged bicyclic compounds.
So pretty useless here.
The older review in Org.Reactions is in volume 11 again not one of the volumes found in MadHatter. The forum library has volumes 1-3, and MadHatter
has vols 25-on but there's a rather large gap. I own vol 10 in hardcopy but not vol 11. Alas. I am not motivated enough to go buy a second hand copy
of vol 11. Not unless I find something I need to make this way.
I have Named Reactions 3rd ed. But what they have is 2 pages and little more than what Merck Index offered. Attached.
And here's the much awaited Bull.Chem.Soc.Japan paper, which I am uploading before reading.
It's interesting but pretty useless since the antecedent papers by same principle author are inacessible in some Japanese-language journal so no
details are at hand on how to prepare the key intermediate alpha-chloro-alpha-sulfonyl ketones. They are using LDA (lithium diisopropylamide) as base.
Volume 11 of Org.Reactions is looking more and more necessary if we are going to make any real headway with Favorskii.
not_important outlined the most generally acceoted mechanish for cases where alpha-hydrogens are present. There is a different mechanism entirely for
instances where alpha-hydrogens are not available. See the JCE paper for details.
[Edited on 13-11-2007 by Sauron]
Attachment: 66_2339.pdf (1.5MB) This file has been downloaded 756 times
Sauron - 29-11-2007 at 07:11
I obtained the Favorskii review chapter from Organic Reactions Vol. 11 courtesy of gsd.
According to it, chloroacetone and bromoacetone do rearrange to propionic acid.
Chloroacetone by treatment with KOH in ether
Bromoacetone by treatment with potassium methoxide in methanol
References 98 and 103.
Unfortunately these references are not very accessible. One is a thesis from the University of Nancy, France, in the 1930s. The other an article from
Bull.Soc.Chim.France also 1930s. You might find the latter in a good library.
The Favorskii is stated to be very sensitive to reaction conditions.
So it would appear that this reaction does work, however little help with experimental details is forthcoming from the literature.
