Sciencemadness Discussion Board

easy synth of C8H8O2 ?

ewok_poacher - 5-9-2007 at 12:50

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 - 5-9-2007 at 14:56

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 928 times

ewok_poacher - 5-9-2007 at 15:57

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 - 5-9-2007 at 16:22

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 - 5-9-2007 at 16:31

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]

ewok_poacher - 5-9-2007 at 16:42

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 - 5-9-2007 at 16:53

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 - 5-9-2007 at 17:07

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...



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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 997 times

ewok_poacher - 5-9-2007 at 17:11

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 - 5-9-2007 at 17:37

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 - 5-9-2007 at 18:54

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 - 5-9-2007 at 19:15

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

Sauron - 5-9-2007 at 19:21

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 - 5-9-2007 at 19:41

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

Rosco Bodine - 28-11-2010 at 21:39

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 799 times

Attachment: US4208519_Cyanuric_acid_chlorination_with_Hypochlorite.pdf (138kB)
This file has been downloaded 1240 times

Attachment: pH sensitivity of reaction biochemj01057-0138.pdf (698kB)
This file has been downloaded 749 times

[Edited on 29-11-2010 by Rosco Bodine]

Rosco Bodine - 1-12-2010 at 23:32

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 1420 times