chemwizard
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Phenyl ethyl alcohol
I am trying to make Phenyl ethyl alcohol directly from styrene monomer rather than going via the conventional styrene to styrene oxide and then
reduction to phenyl ethyl alcohol using the boron catalyst.
Can anyone highlight better options?
Thanks.
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not_important
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hydroboration for 2-phenyl, which I am assuming you mean.
http://www.organic-chemistry.org/frames.htm?http://www.organ...
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chemwizard
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yes.........hydroboration is what i mean..........can you suggest a better option, because hydroboration becomes very expensive method because teh
catalyst cannot be recovered or reused.
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Nicodem
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You don't need any catalyst for hydroboration.
Anyway, I would assume that if you want the less expensive route and don’t mind the reduction in yield and more work, the least expensive route
would be to epoxidaze the styrene (with H2O2/cat., Oxone, sodium percarbonate, etc.), rearrange the epoxide to 2-phenylethanal (there is a method
using only silicagel at reflux, if I remember corectly), then reduce the aldehyde to 2-phenylethanol.
…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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chemwizard
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Currently i am following the same route..........that is.....epoxidation of styrene monomer to styrene oxide with H2O2 and PTC and then direct
reduction of the oxide to 2-Phenyl ethanol.
Acutally, i had come to know that there is a more economical and single step reaction with good yields which directly converts the styrene to 2-Phenyl
ethyl alcohol and i am looking for that.
Thanks for the reply, though.
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garage chemist
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Is there a method to make 2-phenylethanol from phenylacetic acid ethyl ester?
I think I once read about a method for the reduction of esters where the acid component of the ester gets reduced to the alcohol.
EDIT: I found it: it's the Bouveault-Blanc-reduction.
With sodium in Ethanol, one can reduce (m)ethyl phenylacetate to 2-phenylethanol.
[Edited on 5-9-2006 by garage chemist]
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solo
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Here in is an article of the bio syntheis as well as a summary history and references of the different methods used to make it ..............solo
--------------------------------------------------------------------------------------
Biotechnological production of 2-phenylethanol
M.M.W. Etschmann · W. Bluemke · D. Sell J. Schrader
Appl Microbiol Biotechnol (2002) 59:1–8
Abstract
2-Phenylethanol (2-PE) is an important flavour
and fragrance compound with a rose-like odour.
Most of the world’s annual production of several thousand
tons is synthesised by chemical means but, due to
increasing demand for natural flavours, alternative production
methods are being sought. Harnessing the Ehrlich
pathway of yeasts by bioconversion of L-phenylalanine
to 2-PE could be an option, but in situ product removal
is necessary due to product inhibition. This review
describes the microbial production of 2-PE, and
also summarizes the chemical syntheses and the market
situation.
Attachment: Biotechnological production of 2-phenylethanol .pdf (108kB)
This file has been downloaded 1252 times
It's better to die on your feet, than live on your knees....Emiliano Zapata.
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Nicodem
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Chemwizard, could you be a bit more verbose and explain what you mean? Are you already using the:
a.) hydroboration>oxidation with H2O2;
b.) styrene>styrene oxyde>reduction with BH3*BF3;
b.) styrene>styrene oxyde>2-phenylethanal>reduction with whatever;
c.) other?
From none of your posts it isn't clear enough not even which of these routes you use. And give some more details, like reagents used and batch size.
But anyway, given the low price of 2-phenylethanol, any of these processes is like throwing money trough the window. I doubt the production of
2-phenylethanol from styrene can ever be made more economical than the usual Friedel-Crafts alkylation of benzene with ethylene oxide. Perhaps the
most economical route from styrene would be epoxidation of styrene followed by reduction with H2/Pd-C.
To Garage chemist:
Nowadays in the laboratory experiments, LiAlH4 is generally is used for the reduction of esters to alcohols. I haven’t yet seen the Na/alcohol
method used in practice – it is more of a historical curiosity. There are other methods, for example NaBH4 (which by itself does not reduce esters)
can under certain conditions reduce esters to alcohols.
[Edited on 5-9-2006 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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chemwizard
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Friend,
Commercially, I am already employing the styrene to styrene oxide and reduction of styrene oxide to 2-PEA by Hydrogenation. But this method is very
lengthy, cumbersome and generates water pollution. So I plan to shift to a more efficient method.
I even tried hydroboration method as a new alterantive but it isnt as cost effective as the current method of Styrene to styrene oxide to 2-PEA, so I
cannot scale this method commercially.
Regarding what garage chemist suggests - reducation of ester to alcohol is much more expensive then anything else.
Actually I had read an article on net which referred in just one sentence that - Styrene can directly be converted to 2-PEA in single step without
going through the styrene oxide and that the method is very cost effective. But since it didnt state any references, I was wondering how it could be
done by a method which is more cost effective then the current process of Styrene to Styrene oxide to 2-PEA.
I hope that this clears your confusion.
Hope to get some feedback from you, friends!
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chemwizard
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To Solo,
Thanks for the biotechnological production of 2-PEA. I will just go through it and i hope that it turns out to be more cost effective then the current
process that i am using commercially.
Commercially, I am already employing the styrene to styrene oxide and reduction of styrene oxide to 2-PEA by Hydrogenation. But this method is very
lengthy, cumbersome and generates water pollution. So I plan to shift to a more efficient method.
To Garage Chemist,
Thanks for the suggestion of reduction of ester to alcohol. But in all ways that would turn out to be more expensive than my current process that i am
using.
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Sudhir
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Phenylethylalcohol
I am trying to convert styrene oxide to phenyethylalcohol using Raney nickel in an aqueous media-how are the yields and how to supress formation of
ethyl benzens?
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chemwizard
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Take 10% Pd/C and use 1% by weight with respect to Styrene oxide and use the Pd/C for approximately 40-45 batches for cost effectiveness.
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Sudhir
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Thanks for the sugetion.Would like to know what solvent is preferred?
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chemwizard
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you can use Methanol or IPA depending upon what you prefer. But methanol is preferrable because it is cheaper than all solvents.
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Sudhir
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Thanks for the suggetion.Methanol will be preffered as it is cheaper.
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