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hector2000
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Thanks Sauron(khorb koon)
I know i can build tetrabutyltin but now i should use lab grade tetrabutyltin because i sholud gve L-Pac sample.
I found Tetra-nButyltin here(not expensive)
If this is possible please guide me for Seo2 reaction
I have suggestion:
FC reaction between 1,1 dichloroacetone and benzene will not help our?
[Edited on 4-5-2009 by hector2000]
Chemistry=Chem+ is+ Try
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Sauron
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F-C alkylation of benene with 1,1-dichloroacetone ought to work. Can you buy it?
I thought of this also a few days ago but did not have time to check the literature.
Chloroacetones are nasty.
I will look in Pacquette's book for typical SeO2 oxidation.
[Edited on 5-5-2009 by Sauron]
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Sauron
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Eureka!
Here is a short cheap prep of PhCOCOMe aka "acetylbenzoyl" that was jiding in Org.Syn. I told you to search there!
1. Buy or make propiophenone Ph-CO-CH2-Me
You make it by FC acylation of benzene with propionyl chloride
2. Treat with methyl nitrite (you generate yourself, easy - MeOH, NaNO3, H2O, cold dil H2SO4) to get
Ph-CO-C(=NOH)-Me
Isonotrosopropiophenone
3. Hydrolyze with dil H2SO4(details included)
No SeO2 needed.
PDF attached
Attachment: PhCOCOMe.pdf (177kB)
This file has been downloaded 2402 times
[Edited on 5-5-2009 by Sauron]
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Nicodem
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I seriously do not know if this thread is supposed to be for making fun out of Hector's ignorance and laziness or is this supposed to be a serious
discussion...
Anyway, I don't get the point. It is not possible to use pyruvic acid chloride in Friedel-Crafts acylations. That would yield acetophenone and not
PhCOCOMe. Also, I have serious doubts about Hector being able to do what none has yet been able to do, that is to acylate benzene with oxalyl chloride
to give PhCOCOCl. I have not seen any experimental data nor the output of his famous GC-MS. Where are the chromatograms and mass spectra?
One of the published methods for preparing racemic PAC is to nitrosate propiophenone, reduce with NaBH4 and hydrolyse the alpha-hydroxyoxime. So
Sauron, do I have to assume that you are fooling with Hector by exploiting his laziness and reluctance to search the literature? If so, maybe I should
just close this thread. This forum is for amateurs to share knowledge and not for making fun out of wannabe professional chemists who are too lazy to
go to the library and rather want to exploit amateurs to do this.
Also, Hector, are you planning to fraud a pharmaceutical company by selling them racemic PAC? You really must be naive to believe that they will trust
your own declaration of optical purity rather than checking in their own lab. Please, do not sell us bullshit about how you are going to resolve the
enantiomers because no resolution method ever can be cheaper and more efficient than the L-PAC production through biofermentation.
…there is a human touch of the cultist “believer” in every theorist that he must struggle against as being
unworthy of the scientist. Some of the greatest men of science have publicly repudiated a theory which earlier they hotly defended. In this lies their
scientific temper, not in the scientific defense of the theory. - Weston La Barre (Ghost Dance, 1972)
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hector2000
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Quote: Originally posted by Nicodem  | I seriously do not know if this thread is supposed to be for making fun out of Hector's ignorance and laziness or is this supposed to be a serious
discussion...
Anyway, I don't get the point. It is not possible to use pyruvic acid chloride in Friedel-Crafts acylations. That would yield acetophenone and not
PhCOCOMe. Also, I have serious doubts about Hector being able to do what none has yet been able to do, that is to acylate benzene with oxalyl chloride
to give PhCOCOCl. I have not seen any experimental data nor the output of his famous GC-MS. Where are the chromatograms and mass spectra?
One of the published methods for preparing racemic PAC is to nitrosate propiophenone, reduce with NaBH4 and hydrolyse the alpha-hydroxyoxime. So
Sauron, do I have to assume that you are fooling with Hector by exploiting his laziness and reluctance to search the literature? If so, maybe I should
just close this thread. This forum is for amateurs to share knowledge and not for making fun out of wannabe professional chemists who are too lazy to
go to the library and rather want to exploit amateurs to do this.
Also, Hector, are you planning to fraud a pharmaceutical company by selling them racemic PAC? You really must be naive to believe that they will trust
your own declaration of optical purity rather than checking in their own lab. Please, do not sell us bullshit about how you are going to resolve the
enantiomers because no resolution method ever can be cheaper and more efficient than the L-PAC production through biofermentation.
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Really i am tired of accuse.when you stop it?
Probably i am crazy and did this analyze in my dream with GC-MS?(hmmm sweet dream)
This lazy people did 20 time raction so far(from 4 day ago).
This lazy people setup GC-Ms(difficult work because you should provide vaccum and this take 24hour)for every test.
This lazy spend lot of money for this reaction.
Important to know that all of these work did by a person that dont have one hand,one eye,and two finger from right hand therefore i am very lazy.
Excuse this lazy person and this person will leave this forum
If Sauron want to see analyze page(GC-MS) i will send it by PM
Bye
Chemistry=Chem+ is+ Try
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Sauron
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Nicodem, let me assure you that I am studying this for my own amuse,emt and not playing cat and mouse with hectotr,
So if you close this thread you will be doing an injustice to everyone participating in it.
DJK90, panziamdi amd I are sharing information with each other, hector is an ancillary bystander.
I do not follow your remark that pyruvoyl chloride would give acetophenone (like acetyl chloride) under FC acylation conditions. Is that supported in
the lit.?
The route from propio[hemone was suggested earlier by DJK but he made an error about the product. I revived this a post up from yours, based om
Org.Sy. procedures
I looked for FC acylation of benzene with (COCl)2 but Org.Reactions 3 covers alkylations only. I assume this would have been done in the 19th century
amd thus best recourse in lack of a focused review is Beilstein. You seem to think it has never been done, why not?
Oxalyl chloride acylates napthalene readily.
See Aldrich tech bulletin and refs, attached.
Attachment: al_techbull_al110.pdf (253kB)
This file has been downloaded 1627 times
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Sauron
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I stated far upthread that the racemic PAC will have to be resolved to an ee at least as good as what the biotech processes give c.ee 90%.
Hector has three choice
Traditional - fract cryst. of a derivative made with a chiral compounm e,g, tartaric acid
Chiral chromatography on a prep scale
Enzymatic resolution if such a method exists for this substrate.
The second method is probably unapproachable.
The first is laborious.
The third may be best if it exists.
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Nicodem
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| Quote: Originally posted by hector2000 |
Excuse this lazy person and this person will leave this forum
If Sauron want to see analyze page(GC-MS) i will send it by PM
Bye
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Seems like you finally understood that "The art and science of amateur experimentalism" has nothing to do with profit seeking. It is always nice to
see someone finally starts respecting our ethics, even though only out of resentment. 
| Quote: Originally posted by Sauron | Nicodem, let me assure you that I am studying this for my own amuse,emt and not playing cat and mouse with hectotr,
So if you close this thread you will be doing an injustice to everyone participating in it.
DJK90, panziamdi amd I are sharing information with each other, hector is an ancillary bystander. |
That was the only reason why I did not closed the thread when I was supposed to. But the more I followed the more it appeared to me that you were just
fooling around with Hector. Sorry if I had the wrong impression. Things are not always like they appear to be and I will respect the sincere interest
on the topic as long as it will remain sincere.
| Quote: | | I do not follow your remark that pyruvoyl chloride would give acetophenone (like acetyl chloride) under FC acylation conditions. Is that supported in
the lit.? |
There is not a single report of a Friedel-Crafts acylation with pyruvic acid chloride in the literature. There can be two reasons: a.) nobody ever
tried because expecting decarbonylation in the presence of AlCl3 (keep in mind that decarbonylation is a problem already during the formation of
pyruvic chloride and only mild reagents like Cl2CHOMe give good yields); or b.) nobody was able to get it to work and never considered to report what
was already considered obvious by that time. The option a. seems unlikely, because there are conditions which are known to inhibit decarbonylations to
a minimum where this is possible (like using MeNO2 or CS2 as solvent and milder acids as catalysts) and so I think someone must have checked them on
this acid chloride. I believe the reason b. to be more likely.
| Quote: | | The route from propio[hemone was suggested earlier by DJK but he made an error about the product. I revived this a post up from yours, based om
Org.Sy. procedures |
That is what lead me to believe that you were playing cat and mouse, because one of the simplest syntheses of PAC is to start from propiophenone
nitrosation, but not the way you presented it (for a moment, I thought that was some kind of a funny diversion - I mean SeO2 for an industrial process
and such!).
| Quote: | I looked for FC acylation of benzene with (COCl)2 but Org.Reactions 3 covers alkylations only. I assume this would have been done in the 19th century
amd thus best recourse in lack of a focused review is Beilstein. You seem to think it has never been done, why not?
Oxalyl chloride acylates napthalene readily. |
This was already discussed in an earlier thread. Essentially, it is possible to do a Friedel-Crafts with oxalyl chloride but like the examples in that Aldrich review show, this
can be done in a way where decarbonylation of the intermediate arylglyoxalyl chloride is prevented by its further reaction (like in the case of
naftalene or in the examples where a double acylation to ArCOCOAr products is given). Of course, if you use AlCl3 in solvents like CH2Cl2 or do not
keep the temperature low enough, the oxalyl chloride decomposes even before reacting with the substrate. Otherwise, Friedel-Crafts with oxalyl
chloride gives benzoic acids, benzoyl chlorides, ArCOCOAr and/or ArCOAr (depending on the conditions and work-up: there is an old paper describing
these experiments of acylating benzene with ClCOCOCl, but at the moment I can't find it - I will post it when I figure out where I saved it). The
exceptions are the substrates nuclephilic enough so that a Lewis acid catalyst is not required and therefore no decabonylation can happen (like
indole, for example).
This is due to the same property of oxalyl chloride that makes it so suitable for the formation of acid chlorides (that it gives off only gaseous
products like CO, CO2 and HCl), but in this case it leads to undesirable reactions. I actually believe that it might be possible to use some of these
Lewis acid sensitive acid chlorides like alpha-oxo-acid chlorides and alkyl chloroformates in Friedel-Crafts acylations, it is just seems that nobody
have developed a general method.
[Edited on 5/5/2009 by Nicodem]
…there is a human touch of the cultist “believer” in every theorist that he must struggle against as being
unworthy of the scientist. Some of the greatest men of science have publicly repudiated a theory which earlier they hotly defended. In this lies their
scientific temper, not in the scientific defense of the theory. - Weston La Barre (Ghost Dance, 1972)
Read the The ScienceMadness Guidelines!
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Sauron
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I'm sitting here at the scanner 12 hrs a day digitizing Mellor (see New Book Thread-Inorganic for evidence) and have no time for gamesmanship.
When DJK posted about benzene and oxalyl chloride in FC, he mistakenly thought the product would be "acetylbenzoyl" but of course it would not be,
that was when I stated that ti get the diketone by that reaction, the acid chloride would have to be pyruvoyll.
The absence of literature was not encouraging but, I did not have time for a proper search.
Then we went off on a tangent because I stumbled across that recent organostannane paper.
That was interesting to me.
Then a day or two ago while looking for SeO2 methodology I ran into the nitrosation of propiophenone followed by acid hydrolysis to get to
acetylbenzoyl. So I posted that. Closely akin to the racemic PAC method you mention, just a swap of order of steps.
Peripatetic meanderings, no doubt, but not too bad for being done during breaks from scanning.
Same diketone acetylbenzoyl is used in classical prep of racemic ephedrine an reductive amination with MeNH
Proper name
1-Phenyl-propane-1,2-dione
Can also be obtained by SeO2 oxidation of phenylacetone.
[Edited on 5-5-2009 by Sauron]
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DJF90
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Couple of points from me:
I have no interest in l-PAC itself, just the organic chemistry involved in the synthesis. It was quite intriguing to find out that pyruvic acid does
not form an acyl chloride by "conventional means"... I still propose that the ketal protected acid be tried to see if this works instead.
When I suggested the use of oxalyl chloride I did not expect the prouct to be "acetylbenzoyl", but merely 1-oxo-1-phenyl-propionic acid, which is what
I seemed to remember l-PAC being from a quick glimpse of its structure. I should have double checked the structure before I posted, and I am sorry for
not doing so.
Interestingly I've just found an orgsyn article using oxalyl chloride in friedel-crafts alkylation. I had read that the reaction forms an acyl
chloride (I assumed -C(O)COCl to be the group added), but I didnt realise that the oxalyl chloride fragments first to form phosgene. The second
article is a similar reaction but is less explicit about what happens:
http://www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=cv7...
http://www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=CV5...
Oxidation with SeO2 was first mentioned by Sauron earlier in this thread (not sure of his suggested substrate). The I was flicking though a book on
bifunctional compounds ("Bifunctional Compounds" by Ward, Oxford Chemistry Primer #17) and randomly came across a-oxidation of ketones with SeO2,
forming the 1,2-diketone. I remembered this thread and posted accordingly.
As a side note: The oxford chemistry primers are really good compact sources of specific knowlege. It is useful to have a selection as when you get
stuck on a designing a synthesis and can't remember an FGI or stereo/chemoselectivity then you just have to reach for the appropriate primer. I
thoroughly recommend them and over the summer when I have alot more time than now (I have preliminary exams in 5 weeks) I shall borrow a couple of
useful ones from the library here (organic chemistry of course!) and scan them in (so long as they aren't already on giga.
Sauron: I've noticed that lately your typing isnt as good at it used to be. You havent damaged your extremities have you?
[Edited on 5-5-2009 by DJF90]
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Sauron
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It's the eyes not the fingers. Or I should say "eye" since one is long gone,
Assumin that the propiophenone route is setlled upon, SeO2 is no longer required.
Propiophenone + MeONO
Ph-CO-C(=NOH)-Me + H2SO4 -> Ph-CO-CO-Me
Reduction NaBH4 -> DL-PAC
Piece of cake
Comes the resolution, bubble bubble toil and trouble...
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Sauron
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DJK, in the first example from Org.syn. (COCl)2 is reacted with AlCl3 in DCM in absence of any aryl substrate, this is not FC acylation.
Will AlCl3 + phosgene in solution acylate an arene in absence of oxalyl chloride? Well, phosgene is an acid chloride,
In the second example, the initially formed acid chloride is deliverately hydrolyzed with aqueous HCl bringing about decarboxylation. This begs the
question of whether the Ar-CO-COCl is isolable under any consitions.
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DJF90
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Well I suppose it should be isolatable so long as it is kept as the chloride, seeing as decarboxylation only occurs when the carboxylic acid is
formed?
From the acyl chloride on react with MeCu (not sure if this is quite the correct formula?) Would normally use a corey house reagent (LiCuR2) but
figured for ease and simplicity (no methyllithium needed) methylcopper could be used(formed from MeMgX and CuX?)?
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Sauron
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What do you think about F-C alkylation of benzene w/ 1,1-dichloroacetone?
Product Ph-CHCl-CO-Me
1-Phenyl-1-chloroacetone.
Hydrolyze w/ sod.carbonate to DL-PAC.
hector's initiative.
The reagent is cheap. I expect reagent and product to be lachrymatory.
[Edited on 5-5-2009 by Sauron]
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Nicodem
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Nice finds DJF. I was not aware examples this reactions were at Org. Synth. as well.
The decarbonylation (not to be confused with decarboxylation of alpha-oxoacids which yields aldehydes!) happens due to Lewis acid induced carbocation
fragmentation of oxalyl chloride (like in the first Org. Synth. example) or by the same mechanism at the stage of the unstable ArCOCOCl. In any case
acylium cations and carbocations in general tend to fragmentate or rearrange unless first consumed by a competing reaction (like acylation in case of
Friedel-Crafts), but some are so unstable that under some conditions fragmentate even earlier. For example, the discussed alpha-oxoacylium
carbocations are highly unstable and decarbonylate, but also (as reported already by Friedel and Crafts in their seminal papers) carbocations derived
from alkyl chloroformates (decarboxylation) and primary alkyl halides (rearrangement).
Sauron, the Friedel-Crafts reaction using phosgene is known for a long time already and it gives benzoic acids and benzophenones in a conditions
depending ratio (see The journal of industrial and engineering chemistry, 14 (1922) 406-408 for the first study).
Attached is a paper dealing with the Friedel-Crafts acylation with oxalyl chloride. For those interested in finding more on this, it also has some
references to earlier use of this reaction for the synthesis of benzoic acids:
Friedel-Crafts Reaction of Oxalyl Chloride with Pentamethylbenzene
N. E. Alexandrou
J. Chem. Soc. (C), 1969, 536-537.
Attachment: phpaMwsOD (254kB)
This file has been downloaded 823 times
Edit: Seems like the attachment function is malfunctioning again. My file was renamed to some nonsense code. However, I downloaded it and renamed it
to .pdf and it opens in Acrobat.
[Edited on 5/5/2009 by Nicodem]
…there is a human touch of the cultist “believer” in every theorist that he must struggle against as being
unworthy of the scientist. Some of the greatest men of science have publicly repudiated a theory which earlier they hotly defended. In this lies their
scientific temper, not in the scientific defense of the theory. - Weston La Barre (Ghost Dance, 1972)
Read the The ScienceMadness Guidelines!
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DJF90
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Sauron: I can't see a problem with 1,1-dichloroacetone in a FC reaction. It doesnt look as though the carbocation can rearrange either.
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Sauron
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Thanks Nicodem.
It was actually hector who wanted to do the FC w/oxalyl chloride rather than the stepwise reaction of oxalyl chloride with PhSnnBu3 and MeSnnBu3, a
reaction reported in last month's JOC. I liked the organotin route's novelty as cost and pharmaceutical acceptibility are not my worry.
That does give "acetylbenzoyl" but clearly will never be economically competitive with propiopheone/MeONO et seq. much less biotech.
And thanks DJK, I will see if 1m1-dichloroacetone is in the Org.React. V3 FC review.
[Edited on 6-5-2009 by Sauron]
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Sauron
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I only just obtained a translation of a Ber. paper on pyruvoyl vhloride from TMS-pyrucate and (COCl)2.
This makes it abundantly clear how fragile pyruvoyl chloride is, something no apparent from the Org.Syn. prep.
[Edited on 6-5-2009 by Sauron]
Attachment: Haeusler and Schmidt Pyruvic Acid Chloride.pdf (43kB)
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Sandmeyer
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| Quote: Originally posted by Sauron | Thanks Nicodem.
It was actually hector who wanted to do the FC w/oxalyl chloride rather than the stepwise reaction of oxalyl chloride with PhSnnBu3 and MeSnnBu3, a
reaction reported in last month's JOC. I liked the organotin route's novelty as cost and pharmaceutical acceptibility are not my worry.
|
Haha, no, no - organotin reactants are last resort chemistry...  What JOC paper
are you talking about btw...? How is the oxalyl chloride to be used to make phenylacetylcarbinol? Even if it worked (which it will not with AlCl3 -
see DJF90's post containing orgsyn refs.) you would add a 2 carbon chain, this chain is already present in readily available mandelic acid. A
scifinder search should be done but I can't do it now, however google search on mandelic acid in this context gave following reference: J. Am. Chem.
Soc., 1932, 54 (1), pp 234–236 DOI: 10.1021/ja01340a033 but, why speed, why push? 
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Sauron
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It might help if you bothered to read the thread.
hector2000 wants to make L-PAC and is looking at non-biotech routes.
I could care less about L-PAC but was kicking some idead around.
Organotin alkyls of the tpe nBu3SnR where R is alkyl or aryl, react with oxalyl chloride to produce diketones. The sequential reaction of nBu3SnPh,
and nBu3SnMe, with oxalyl chloride gives PhCOCOMe.
The same diketone is produced by nitrosating propiophenone with MeONO and hydrolyzing w/H2SO4. This is described in Org Syn and the diketone employed
in synthesis of racemic ephedrine..
Hector has a lot to learn abour optical resolution.
But that's not my headache,
[Edited on 5-11-2009 by Polverone]
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turd
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| Quote: Originally posted by Sandmeyer | | A scifinder search should be done but I can't do it now, however google search on mandelic acid in this context gave following reference: J. Am. Chem.
Soc., 1932, 54 (1), pp 234–236 |
That sounds much more OTC and amateur friendly. I wonder if one would need less of an MeMgI excess if one reacted the mandelamide beforehand with Na
to obtain the Na-salt? And whether one could use other amides - mandelamide is expensive!
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Sauron
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Interesting although I fail to see what is OTC about it.
Attachment: ja01340a033.pdf (58kB)
This file has been downloaded 1479 times
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hector2000
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I did Reaction between 1,1 dichloroacetone and benzene in FC and then hydrolyze it and got DL-PAC
but yield is bad.
Mandelamide method is not easy as 1,1dichloroacetone method but is interesting.
Mandelamide is very expensive and i didnt find method for making it.
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Sauron
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Hecttor, you mudt nunderstand that this mandelamide methos makes L-PAC and not DL-PAC and therefore, solves the problem of resolving the optical
isomers.
You make mandelamide from mandelic acid and ammonia.
Give me a little tome to study thw paper.
[Edited on 9-5-2009 by Sauron]
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turd
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You must be kidding - the carboxylic acid to amide transformation is a classic. I can only conclude that you didn't find it because you didn't search.
Anyway, if you're going to buy it instead of making it, you could just as well buy mandelonitrile which is quite cheap (the racemate) and probably
needs less MeI.
Damn, my intent was to not participate in this thread anymore and now I did it again. 
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