ewok_poacher
Harmless
Posts: 11
Registered: 3-9-2007
Member Is Offline
Mood: No Mood
|
|
easy synth of C8H8O2 ?
starting with
2-Amino-3-phenyl-propanoic acid (C9H11NO2)
using Strecker Degredation (bleach) to reach
C8H8O
then using chromic acid to reach
C8H8O2
Will this work ??
Synth has not been attempted and is just a topic for discussion.
Any input is appreciated.....
|
|
|
solo
International Hazard
Posts: 3975
Registered: 9-12-2002
Location: Estados Unidos de La Republica Mexicana
Member Is Offline
Mood: ....getting old and drowning in a sea of knowledge
|
|
2-Amino-3-phenyl-propanoic acid (C9H11NO2)
.......to by Strecker Degredation (bleach) to reach
..you mean TCCA right!
Acetophenone -C8H8O
------> ------------>
..............well I found this that may be of some help, if I understood your synthesis......solo
---------------------------------------------------------------------------------------
NEW METHOD FOR THE SYNTHESIS OF NITRILES FROM O-ARYLALDOXIMES WITH ZrCl4
Chiho Tsuji; Etsuko Miyazawa; Takeshi Sakamoto; Yasuo Kikugawa
Synthetic Communications Volume 32, Issue 24 January 2002 , pages 3871 - 3879
Abstract
Nitriles were readily synthesized from the corresponding O-phenyl- or O-(p-cyanophenyl)-aldoximes with ZrCl4 in nitromethane or in benzene.
Keywords: O-Aryloxime; Nitrile; ZrCl4
[Edited on 5-9-2007 by solo]
[Edited on 5-9-2007 by solo]
Attachment: NEW METHOD FOR THE SYNTHESIS OF NITRILES FROM O-ARYLALDOXIMES WITH ZrCl4.pdf (485kB)
This file has been downloaded 921 times
It's better to die on your feet, than live on your knees....Emiliano Zapata.
|
|
|
ewok_poacher
Harmless
Posts: 11
Registered: 3-9-2007
Member Is Offline
Mood: No Mood
|
|
So are you saying that I just got the process name wrong it is actually done by use of the citric cycle?
What are your thoughts on the end result?
Do you believe that this would produce C8H8O2 ?
Thank you
|
|
|
Sauron
International Hazard
Posts: 5351
Registered: 22-12-2006
Location: Barad-Dur, Mordor
Member Is Offline
Mood: metastable
|
|
Your use of molecular formulas rather than structures is confusing, @ewok_poacher.
Is acetophenone your target? As solo points out it is C8H8O not C8H8O2.
Your starting material is phenylalanine, an a-amino acid. Correct?
Please be a little less coy about your target molecule.
|
|
|
solo
International Hazard
Posts: 3975
Registered: 9-12-2002
Location: Estados Unidos de La Republica Mexicana
Member Is Offline
Mood: ....getting old and drowning in a sea of knowledge
|
|
ewok_poacher...
You give very little information I sort of have to read between the lines.....if you put a bit of effort and some basic research yourself the end
result might be brighter............solo
[Edited on 5-9-2007 by solo]
It's better to die on your feet, than live on your knees....Emiliano Zapata.
|
|
|
ewok_poacher
Harmless
Posts: 11
Registered: 3-9-2007
Member Is Offline
Mood: No Mood
|
|
I was trying to let this post go under the radar of some undesirable readers, but here goes ......
Starting with
phenylalanine
and treating it with bleach to get
phenylacetaldehyde
Then using sulfuric acid and a dichromite salt to male chromic acid,
oxidise the aldehyde to the acid via reflux to get
phenylacetic acid
wich can then be purified from the mix via steam distillation
Is that a little better??
|
|
|
Sauron
International Hazard
Posts: 5351
Registered: 22-12-2006
Location: Barad-Dur, Mordor
Member Is Offline
Mood: metastable
|
|
Rather a long way round the block to make PAA.
Usually you start with toluene, make a benzyl halide of your choice then convert to phenylacetonitrile and hydrolyze.
Or, start with benzyl alcohol, and halogenate that, then proceed same way.
Classical stuff.
Anyway solo nicely provided a method for making phenylacetonitrile (benzyl cyanide) from benzaldehyde, hydroxylamine nydrochloride and zirconium
tetrachloride. Is the Zr reagent readily available? I'd expect it to be expensive.
Gee, I wonder who the undesirable readers might be?
[Edited on 6-9-2007 by Sauron]
|
|
|
solo
International Hazard
Posts: 3975
Registered: 9-12-2002
Location: Estados Unidos de La Republica Mexicana
Member Is Offline
Mood: ....getting old and drowning in a sea of knowledge
|
|
| Quote: | Then using sulfuric acid and a dichromite salt to male chromic acid,
oxidise the aldehyde to the acid via reflux to get
phenylacetic acid
wich can then be purified from the mix via steam distillation |
...............where is this from ....is there a reference to check ......solo
Note:
In a silica basin of about 35 cm. diameter, a mixture of 2.5 kilos of benzyl cyanide [3] and 7.5 kilos of 70% sulfuric acid is warmed until a few
bubbles of gas appear. The heating is at once stopped, since a very vigorous action now ensues. As the vapors evolved are injurious to health, the
basin is covered when the reaction begins with a sliding cover from which the vapors can be led into water. As soon as the reaction ceases, the
product is poured upon crushed ice in a large, earthenware vessel. Crude phenyl acetic acid, contaminated on the surface with phenyl acetamide, is
precipitated on cooling. In order to remove the amide, the acid is dissolved in lukewarm dilute soda solution. The amide remains undissolved and can
be filtered off, while the phenyl acetic acid goes into solution as sodium salt and is reprecipitated in a sufficiently pure state by the addition of
dilute mineral acid. After drying it is acceptably pure.
Further Purification
The acid is dissolved in five times its weight of boiling water, filtered off and allowed to cool. Phenylacetic acid separates out in an absolutely
pure state in the form of flakes with a mother of pearl lustre. After filtering and drying it possesses a pleasant honey scent.
..............source,
http://www.erowid.org/archive/rhodium/chemistry/phenylacetic...
-------------------------------------------------------------------------------------
Reference Information
An Insight of the Reactions of Amines with Trichloroisocyanuric Acid
De Luca,* Giampaolo Giacomelli
SYNLETT 2004, No. 12, pp 2180–21840
Abstract:
The reaction between amines or a-aminoacids with trichloroisocyanuric acid is studied under various conditions: N,Ndichloroamines, nitriles and
ketones can be obtained from primary amines, while free aminoacids undergo oxidative decarboxylation to the corresponding nitrile of one less carbon
atom.
Key words: dichloroamines, trichloroisocyanuric acid, nitriles,
aminoacids
Note: there's been trial and failures on this synthesis .....read *
[Edited on 5-9-2007 by solo]
Attachment: An_Insight_of_the_Reactions_of_Amines_with_Trichloroisocyanuric_Acid.pdf (68kB)
This file has been downloaded 990 times
It's better to die on your feet, than live on your knees....Emiliano Zapata.
|
|
|
ewok_poacher
Harmless
Posts: 11
Registered: 3-9-2007
Member Is Offline
Mood: No Mood
|
|
My goal is to end up with phenylacetic acid (PAA not PPA - sorry)via very obtainable inexpensive precursors.
sorry for the confusion
I have no references, this has not been attempted by anyone I know. It is just a hypothesis.
[Edited on 5-9-2007 by ewok_poacher]
[Edited on 5-9-2007 by ewok_poacher]
|
|
|
Sauron
International Hazard
Posts: 5351
Registered: 22-12-2006
Location: Barad-Dur, Mordor
Member Is Offline
Mood: metastable
|
|
Solo is steering you to some very fine chemistry, Lidia deLuca is very good. And TCCA is very very cheap swimming pool chlorinator. So Phe (that's the
standard shorthand for phenylalanine) -> phenylacetonitrile -> phenylacetic acid. Fine and dandy.
Is phenylalanine all that cheap compared to toluene or benzyl alcohol? You can use the racemic form (DL-Phe) but even so.
[Edited on 6-9-2007 by Sauron]
|
|
|
DerAlte
National Hazard
Posts: 779
Registered: 14-5-2007
Location: Erehwon
Member Is Offline
Mood: Disgusted
|
|
Slightly OT - this thread emphasizes why I often don't bother reading organic posts. The far too liberal use of undefined & unknown acronyms (to
me, anyhow) causes me to chuck them into a mental rubbish bin. Please define your acronym at least once with the IUPAC or Merck index nomenclature so
we all all know what you are talking about. The same goes for molecular formulae - quite useless except for two symbols or so. Some hint of structure
is needed.
Rant over, Der Alte
|
|
|
Ozone
International Hazard
Posts: 1269
Registered: 28-7-2005
Location: Good Olde USA
Member Is Offline
Mood: Integrated
|
|
I've glossed over this before. Check out:
http://www.sciencemadness.org/talk/viewthread.php?tid=7073&a...
Try the search engine.
I certainly hope your making herbicides...
O3
-Anyone who never made a mistake never tried anything new.
--Albert Einstein
|
|
|
Sauron
International Hazard
Posts: 5351
Registered: 22-12-2006
Location: Barad-Dur, Mordor
Member Is Offline
Mood: metastable
|
|
Phe IS officially sanctioned shorthand for phenylalanine. There is also a single letter code (which I have never bothered to learn). These facilitate
the designation of peptides and proteins which would be onerous to fully name.
For example
Ac-Nle-cyclo(Asp-His-D-Phe-Arg-Trp-Lys)-OH is a fully described cyclic heptapeptide with all amino acids of L-isomer except for phenylalanine which is
D-.
It would be clumsy to have to say
Acetylnorleucylcycloaspartylhistadyl-D-phenylalanylarginyltryophyllysyl)-carboxylate.
As there aren't all that many amino acids, it is not onerous to learn the standard abbreviations. Likewise the protecting groups are also abbreviated,
not terribly systematically, and there are more PGs than AAs. But only a relatively few are used frequently and the others if unfamiliar can be
looked up.
However, as to the general point you are making, I agree with you and said about as much upthread.
|
|
|
Ozone
International Hazard
Posts: 1269
Registered: 28-7-2005
Location: Good Olde USA
Member Is Offline
Mood: Integrated
|
|
Phe is correct. I usually will designate the stereoisomer, vis. L-Phe. The single-letter shorthand is F.
Honestly, I prefer the three-letter designation when reading papers.
Cheers,
O3
-Anyone who never made a mistake never tried anything new.
--Albert Einstein
|
|
|
Rosco Bodine
Banned
Posts: 6370
Registered: 29-9-2004
Member Is Offline
Mood: analytical
|
|
Quote: Originally posted by solo  |
Reference Information
An Insight of the Reactions of Amines with Trichloroisocyanuric Acid
De Luca,* Giampaolo Giacomelli
SYNLETT 2004, No. 12, pp 2180–21840
Abstract:
The reaction between amines or a-aminoacids with trichloroisocyanuric acid is studied under various conditions: N,Ndichloroamines, nitriles and
ketones can be obtained from primary amines, while free aminoacids undergo oxidative decarboxylation to the corresponding nitrile of one less carbon
atom.
Key words: dichloroamines, trichloroisocyanuric acid, nitriles,
aminoacids
Note: there's been trial and failures on this synthesis .....read http://www.4shared.com/file/23648316/3664d88a/phenylalanine_...
[Edited on 5-9-2007 by solo] |
Here's a link that's good now for the phenylalanine_and_TCCA_revival
http://www.sciencemadness.org/talk/files.php?pid=110598&...
I have been looking at this reaction of amino acids with TCCA in regards to conversion of glycine to aminoacetonitrile, and I have not yet been able
to find the reaction mechanism completely described. It appears that the TCCA may be converted in situ to the sodium salt of TCCA, sodium DCCA or
"dicholor" which is possibly a more direct precursor useful for the reaction. TCCA is very acidic, while the sodium DCCA is closer to neutral pH.
The reaction is described to occur under basic conditions and the aqueous solubility of TCCA is low except under basic conditions, when it reacts with
the base and goes into solution as the sodium DCCA. My thinking is that possibly the DCCA could be used from the start of the reaction more
conveniently since it is available in granular pure form. Regarding the mechanism, it would seem that for complete conversion it is unlikely that a
sodium hypochlorite intermediate is the active intermediate, because
an older article has reported efforts to obtain the nitrile from the amino acid does not give complete conversion as is reported for the TCCA method.
See attached article.
Comparing these two articles is causing me to suspect that sodium DCCA is the actual reactant involved in the actual high yield reaction mechanism
leading from the amino acid to the nitrile. Also see attached patent US4208519_Cyanuric_acid_chlorination_with_Hypochlorite
which sheds some light also by indicating that the equilibrium favors the sodium DCCA as the more stable entity in a reaction system containing Sodium
hypochlorite and cyanuric acid, which would be the by product of dechlorination of either TCCA or sodium DCCA. This suggests
that the reaction of the amino acid with sodium hypochlorite
which was described in the older journal article may have proceeded to a complete conversion if cyanuric acid had been an additional reactant.
It seems clear that pH is a governing condition for the course of the reaction and what product may be the result. See article by Wright attached.
Another governing condition appears to be the ratio of chlorine available with regards to the amino acid.
Temperature and duration of reaction is also probably a factor.
Attachment: glycine plus hypochlorite biochemj01063-0172.pdf (1.1MB)
This file has been downloaded 792 times
Attachment: US4208519_Cyanuric_acid_chlorination_with_Hypochlorite.pdf (138kB)
This file has been downloaded 1234 times
Attachment: pH sensitivity of reaction biochemj01057-0138.pdf (698kB)
This file has been downloaded 742 times
[Edited on 29-11-2010 by Rosco Bodine]
|
|
|
Rosco Bodine
Banned
Posts: 6370
Registered: 29-9-2004
Member Is Offline
Mood: analytical
|
|
I just looked at the reaction for this and realized glycine would lead to acetonitrile, rather than aminoacetonitrile.
Attached is a paper which shows the reaction paths for a similar oxidation using alkaline bromine. Thanks solo.
It would seem the interesting product for this reaction
would be phenylacetonitrile gotten by oxidation of phenylalanine .....which should work just fine 
Attachment: Alkaline Bromine Oxidation of Amino Acids.pdf (1.9MB)
This file has been downloaded 1413 times
|
|
|
![[*]](images/xpblue/default_icon.gif){kind=icon}
