IodineForLunch - 8-11-2002 at 18:25
I have recently devoted some time and thought to the synthesis of pyridine and its possible uses. Pyridine is simply a benzene ring in which a
nitrogen in substituted for one of the carbons, C5H5N. According to xrefer.com, it is a "a colorless liquid with a strong unpleasent smell which
boils at 115 degrees." They say it is used as a solvent and in making other chemicals, but they don't say what it is used to make.
The synthesis of pyridine seems to be an elusive process. Some sites mention that it is present in coal tar. However, I did find one interesting
site that talked about the synthesis of pyridine by inducing heterocyclosation of an alkyne with a nitrile to give pyridine derivitives. Thsi
reaction is carried out in aqueous solution at room temperature, and is catalyzed by sunlight. It would seem that pure pyridine could be obtained by
performing this reaction on a mixture of dissolved acetylene and aqueous hydrogen cyanide, as in:
HCN + 2C2H2 ----> C5H5N
Here's the link to the site: http://www.ifok.uni-rostock.de/e/Science/Projects/bhelle/
David Hansen
Hive
PrimoPyro - 8-11-2002 at 19:30
Try using the search engine at the Hive for this topic, in the serious chem forum.
I know it has been covered because I have posted in it.
pyridine
PIPES_B - 10-11-2002 at 04:08
I think a good Synthesis-Base are 1,4-piperidine !
piperidine
The_ChainSaw - 15-11-2002 at 14:10
Are you know the synthesis-steps of
1,4-piperidine-3,6-dione ?
2bob - 18-9-2006 at 19:49
Apparently this can be acheived by heating (300C) sulphuric acid and piperidine (or by using mild oxidising agents). This is sort of good, as pyridine
from the split of piperine into piperidine and piperic acid utilises the waste products of the attempted synthesis of heliotropin from pepper.
2bob - 18-9-2006 at 20:52
another method of reaching pyridine is by heating ammonium mucate or ammonium saccharide with ammonia, as per the production of pyrrole (orgsyn):
http://www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=cv1...
By heating this in ammonia (instead of glycerol) dihydropyridine is formed, which is then oxidised to pyridine. (I have the procedure on my PC but do
you think that I can find the reference?).
not_important - 18-9-2006 at 21:33
Doesn't seem to have your exact process, but does have many related ones:
Heterocycles from Carbohydrate Feedstocks
http://csi.chemie.tu-darmstadt.de/ak/fwlicht/PAPERS/paper263...
2bob - 19-9-2006 at 08:36
the synthesis is as follos:
"E.g. in the synthesis of pyrrole; The diketone (ammonium mucate/ammonium saccharide) can be regarded as a 4-carbon bis-electrophile.
Treatment of the diketone with ammonia as in the pyrrole example gives the dihydropyridine. This can be converted to the pyridine by oxidation."
My question is, what oxidising reagent/catalyst should be utilised?