querjek
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Preparation of adipic acid from lysine?
Hello all,
I've been trying to figure out a scheme to synthesize adipic acid out of lysine, as a little side project this summer for some later plastic-casting.
This is where I've gotten so far:
lysine -- cat. H+ --> lysine lactam
lysine lactam -- NaNO2/H+ --> alpha-diazo lysine lactam
I know the textbook reaction of H2PO2 with diazo- compounds to reduce the N2+ group with a hydrogen, but H2PO2 is not obtainable for me. My most
likely route would be to heat it in acidic conditions (replacing N2+ with an OH-), then reducing from there.
Opening the lactam now (caprolactam) would leave me epsilon-amino-caproic acid.
My main questions are:
-is there a simpler way to go directly from the diazo compound to the saturated lactam?
-where can I go from there? I assume that KMnO4 or H2CrO4 wouldn't oxidise the terminal amine into a carboxylic acid?
And of course, and general tips would be greatly appreciated. Thanks!
it's all about chemistry.
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not_important
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how about hydrolysing nylon 6-6 to get adipic acid and the diamine? If you really want maximum yield it looks to be possible to oxidise the diamine
to the dinitrile, which then could be hydrolysed to more adipic acid:
An efficient and highly selective method for the oxidative conversion of primary amines to the corresponding nitriles using trichloroisocyanuric acid
in the presence of catalytic TEMPO provides a new entry to the synthesis of various aliphatic, aromatic and heterocyclic nitriles in excellent yield.
F.-E. Chen, Y.-Y. Kuang, H.-F. Dai, L. Lu, M. Huo, Synthesis, 2003, 2629-2631.
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UnintentionalChaos
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I've attached the paper not_important was talking about.
You would probably be better off finding some polycaprolactone, depolymerizing with stong base, and oxidizing with KMnO4 or similar. Cyclohexanone can
be reduced with thiourea dioxide (see fairly recent thread), dehydrated to cyclohexene, and cleaved with KMnO4 to adipic acid. I don't see any reason
to do a bayer-villager oxidation on the cyclohexanone if you don't have to.
Attachment: tccaaminenitrile.pdf (29kB)
This file has been downloaded 2964 times
[Edited on 4-1-09 by UnintentionalChaos]
Department of Redundancy Department - Now with paperwork!
'In organic synthesis, we call decomposition products "crap", however this is not a IUPAC approved nomenclature.' -Nicodem
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garage chemist
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Quote: Originally posted by UnintentionalChaos  | Cyclohexanone can be reduced with thiourea dioxide (see fairly recent thread), dehydrated to cyclohexene, and cleaved with KMnO4 to adipic acid. I
don't see any reason to do a bayer-villager oxidation on the cyclohexanone if you don't have to.
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Why do it the easy way if you can use a more complex and expensive method?
Cyclohexanone and -ol (both can be used without difference) can be oxidised with nitric acid to adipic acid:
http://www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=cv1...
I did this reaction myself several times on a preparative scale, making over 250g of adipic acid. It works very nicely.
Adding 0,5g of copper sulfate (plus the ammonium vanadate) to the nitric acid improves the yield further.
It is true that both catalysts are unnecessary when working at a higher temperature, but the yield markedly drops compared to the Cu + V catalysed
reaction if this is done.
If nitric acid is not available, you can probably use an aqueous solution of NaNO3 (not NH4NO3! The nitric oxides may catalyse oxidation of the
ammonium ion, using up the HNO3 prematurely) and H2SO4 at the proper concentration.
Later I saw that polymer grade adipic acid (the cheapest technical grade of adipic acid available) is seriously cheap at Sigma-Aldrich, so I bought a
kilo of that.
[Edited on 1-4-2009 by garage chemist]
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