well i was thinking about making piperdine myself(for use in another synth)
i read about the hoffman rearrangement and tought it could be usefull.So i found a route that starts from adipic acid(or cyclopentanon,if u have it)
it goes like:
now the beckmann rearrangement under influence of H2SO4(or PCl5)
u get piperdin-2-one
reduce that with HCl/zn é Voila...
but the only problem i would think of would be the NH2OH(hydroxylamine)
then i read about amine oxides and the cope elimination reaction.Witch goes like this:
(3R)N + H2O2 -->(3R)N+O- --->(2R)NOH +alkene
But i thougt if i could substitute the R for a H
that wuld get u:
NH3 + H2O2 -->H3N+O- --->NH2OH
What do you think of this reaction?is it possible?High Yielding,....
comments plzz
12AX7 - 21-11-2005 at 15:34
How exactly does Ba(OH)2 reduce a dicarboxylic acid to a mono-ketone?
Timstygian - 21-11-2005 at 15:40
By dry distillation. Similar to calcium acetate-acetone. Only with dicarboxylic acids it forms cyclic ketones.CherrieBaby - 22-11-2005 at 07:08
These are all taken from "Organic Chemistry", Bernthsen, Revised by Sudborough, 1941 edition, Blackie & Sons.
1. When pentamethylene-diamine hydrochloride is strongly heated it yields piperidine.
NH2-CH2-CH2-CH2-CH2-CH2-NH2.HCl --> piperidine
2. The elimination of HCl from 5-chloroamylamine, (CH2Cl-(CH2)3-CH2-NH2. This elimination occurs when an aqueous solution of the base is heated on the
water bath; ring formation takes place, and piperidine HCl is formed.Nicodem - 22-11-2005 at 11:48
Quote:
Originally posted by sterckxke
u get piperdin-2-one
reduce that with HCl/zn é Voila...
Yeah right! Since when can you reduce amides with Zn/HCl?CherrieBaby - 23-1-2006 at 14:33
How about piperidine via the decarboxylation of Pipecolic acid (which is alpha-carboxy-piperidine).
Pipecolic acid can be made from lysine.
L-Pipecolic acid from L-lysine; Bull. Chem. Soc. Jpn. 48, 1341 (1975).
DL-Pipecolic acid from DL-lysine; JOC 55, 738 (1990)Drunkguy - 24-1-2006 at 10:42
For all the pain of the above procedure (Beckmann degradation - it's been a while!), did u guys not know that pyridine can be hydrogenated to
piperidine. I can understand that this is not easy to do though due to the fact that it has to be done under high pressure if using an ordinary
catalyst such as Pt(C). Also the fact that the catalyst will get poisoned if the source of hydrogen is not squeeky clean is another barrier. The
synthesis of diethylamine would not be as difficult though but I guess that piperidine is what we are really shooting for.runlabrun - 24-1-2006 at 14:56
Not to mention the difficulty in obtaining pyridine these days.
Piperidine can be synthesised in easier ways such as those mentioned rather than the method in the original post.
-rlrNERV - 25-1-2006 at 08:01
IIRC, piperidine can be had from the hydrolysis of piperine (1-piperylpiperidine) with a strong hydroxide. I am not sure of the full details as it was
just some random tid bit of information I came across one time, but I do know that piperine can be extracted in good yield from pepper.The_Davster - 25-1-2006 at 16:52
Correct me if I'm wrong, but what Tacho seems to have isolated is piperidine not piperine, which as you know are quite different. Piperine extractions
are usually, AFAIK, carried out by either using ethanol, methanol or DCM, but when piperidine is desired an alcoholic solution of KOH or some other
strong base is used. Am I right in concluding this, because I think there could really be some misunderstanding because of the relative similarity of
these two 'archaic' names (don't get me wrong, I love archaic nomenclature).S.C. Wack - 26-1-2006 at 03:04
OK. Base is added in some procedures as there are supposedly acids that you dont want to extract.
It takes some time refluxing in 10% alcoholic KOH to get piperidine and piperate.The_Davster - 26-1-2006 at 05:54
Yeah, I realize that piperidine and piperine are different, and that the above thread is the extraction of piperine. I meerly posted it as a way to
get piperine as an intermediate for the synthesis of piperidine.
Explosivo, you must mean that Tacho extracted piperine from pepper, not piperidine, right?
Piperine:
Piperidine: Esplosivo - 26-1-2006 at 07:37
Its just that once I remeber reading that piperidine can be made from piperine by refluxing in a strongly basic alcoholic soln. I though that Tacho,
by refluxing the pepper with a strong base would most probably have extracted piperidine rather than piperine. I now realized that piperidine is a
liquid and Tacho's extract is infact solid, therefore I was proven incorrect. I tried the piperine extraction once but resulted in a horrendously
small yield. I will try it again, with DCM and a soxhlet soon.Drunkguy - 26-1-2006 at 09:32
There are synthetic details for the procedure online (if u look in the right place). It did not impress on me that the piperine hydrolysis was useful
for obtaining piperidine but was more geared toward iolating the 3,4-MD-benzoic acidThe_Davster - 26-1-2006 at 17:52
Hmm if I ever end up making an ozone generator, piperine could be interesting to do an ozonlysis with, Could get glyoxal , and some other less interesting aldehydes.
Ozone is not the only thing that could do this IIRC, permanganate solution followed by periodic acid or lead tetraacetate could give the glyoxal as
well.
(hehe HNIW from pepper.....Now thats madscience...)
If extracting piperine from pepper with alcoholic K2CO3, would there be much reaction of the piperine to give piperidine as K2CO3 is a weak base?
)
, and some other less interesting aldehydes.