11-14-02 03:01
No 379463
niacin to pyridine --- would this work, oh gurus de chemie????
seems like a nice place (OTC) to begin to get this oh so elusive molecule.
(Will work for title)
11-14-02 03:03
No 379464
Niacin or nicotinic acid, (produced through the oxidation of methyl ethyl pyridine with HNO3)...
Can you reverse that?
Pyridine: It is made from crude coal tar or from other chemicals based on acetaldehyde and ammonia.
Found here: http://www.chemicalland21.com/arokorhi/l
TTT
Drug shortage is a worldwide problem with neighborhood solutions.
(Hive Bee)
11-14-02 03:11
No 379466
COOH might be reduced to CH3, so one can get methyl-analog and it might be used as substituent for pyridine in many cases, just like toluene is used instead of benzene...
1-2-3 ACiD
(Hive Bee)
11-14-02 03:32
No 379468
often wondered about the effect of the CH3 in various reactions - surely there is an effect
(Hive Bee)
11-14-02 04:04
No 379479
and what you use it for... If pyridine is recommended in a particular rection as catalyst or solvent, I think that a methyl group on it wouldn't be a issue...
1-2-3 ACiD
(Official Hive Translator)
11-14-02 09:40
No 379575
Yes, it will work
Mix 1 part of niacine w/1,2 parts CaO, place in a sand bath, heat to 320 C. After ~1,5hrs decarboxylation's over (could bee longer, since in the original source the rxn is performed on microscale and in a sealed ampoule - the latter requirement undoubtedly stems from the need to measure the yield w/a great precision - figure how you measure the yield when working w/12 mgs of niacine!) Distill the formed pyridine off.
The promised yield is 86-90%
The article was found and submitted by Diafrag of HyperLab - see the original in Russian on Garin's site:
http://chembook.narod.ru/other_articles/
Yours Truly,
Antoncho
(Hive Bee)
11-15-02 05:36
No 379861
After you download the file what program do you use to open it?
I can't open it.
(Hive Bee)
11-15-02 05:45
No 379864
Post 218955 (Antoncho: "All DejaVu programs may now bee downloaded", Tryptamine Chemistry)
Also: http://www.djvu.com/download.html
Also: Do you speek Russian?
There Can Only Bee One - xX www.the-hive.ws Xx
(Hive Bee)
11-17-02 19:11
No 380514
i ahve been struggling with pyridine OTC for a long while-
could you give any refs in english?
thank you, sir...
(Hive Bee)
11-17-02 20:07
No 380534
In addition to what has been posted already, these were found:
Carbon-13 and oxygen-18 isotope effects in the decarboxylation of nicotinic acid of natural isotopic composition.
Zielinski, M.; Zielinska, A.; Papiernik-Zielinska, H.; McKenzie, J. A.; Bernasconi, S.; Paul, H. Isotope Laboratory (Laboratory Nuclear Chemistry), Faculty Chemistry, Jagiellonian University, Krakow, Pol.
Journal of Radioanalytical and Nuclear Chemistry (1998), 230(1-2), 71-74.
Abstract
13C and 18O isotope effects in the decarboxylation of nicotinic acid (I) of natural isotopic compn. above and below its melting temp. were studied and compared with the primary (PKIE) and secondary kinetic isotope effects (SKIE) of 13C and 18O, resp., in the decarboxylation of other heterocyclic acids. The temp. dependence of the 18O SKIE is neg. in the total 221-255° temp. interval investigated initially. The 13C KIE measured above the m.p. of I (235-270°) are located in the range 1.007-1.009. Below the m.p. of I, the 13C KIE are larger and reveal the neg. temp. dependence (13C KIE decreases with the reaction temp. from 1.013 at 230° to 1.0114 at 221°). A discussion of the above isotopic results is presented.
Effect of alkali additions on decarboxylation of nicotinic and isocinchomeronic acids in an aqueous medium.
Suvorov, B. V.; Serazetdinova, V. A.; Lebedeva, O. B. Inst. Khim. Nauk, Alma-Ata, USSR.
Izvestiya Akademii Nauk Kazakhskoi SSR, Seriya Khimicheskaya (1985), (3), 53-7.
Abstract
The decarboxylation of the title acids at 200-300° was retarded by NH3 and esp. by KOH.
And this one is quite close, it could have some other references or information.
Decarboxylation of some 2-substituted pyridinecarboxylic acids.
Moser, Russell J.; Brown, Ellis V. Dep. Chem., Univ. Kentucky, Lexington, Ky., USA.
J. Org. Chem. (1972), 37(24), 3941-2.
Abstract
The rates of decarboxylation of 2-chloro- and 2-nitro-x-pyridinecarboxylic acids (x = 3,4,5) and 2-bromo-, 2-amino-, and 2-acetamido-3-pyridinecarboxylic acids as well as 3-pyridinecarboxylic acid were studied in 3-nitrotoluene. Only 3-pyridinecarboxylic acids with electron withdrawing groups at the 2-position decarboxylated below 227°. It is possible to decarboxylate 3-pyridinecarboxylic acids, at lower temps., by placing an electron withdrawing group ortho to the carboxyl group.
(Hive Bee)
11-17-02 20:44
No 380539
located this
Patent US3335144 Method of producing pyridine and 2-picoline by decarboxylation
..it relates to preparing pyridine and 2-picoline from 2,6-lutidine (dimethylpyridine- 27175-64-0)
that JOC ref is right upstairs from me. "hold that elevator"
whew what a stair trip --- anywho
first question - could niacin be viewed as a "pyridinecarboxylic acid"?
(i am on thin ice here folks) and if so where is the H+? these brilliant chemists are utilizing nitrotoluene as a solvent at a lower reaction temp. having said that - what does it mean?
i just used chemfinder and typed the question and guess what - niacin popped up. amazing.
nitrotoluene -- memory says OTC (at least realizable). soooooo...
does this mean we are here?
niacin + nitrotouene ===> pyridine + something else
and just how does the carboxyl group get stripped off by the solvent?
(Chief Bee)
11-19-02 03:54
No 381001
J. Org. Chem. 37, 3941-2 (1972) (../rhodium/pdf /decarboxylat
(Hive Bee)
11-19-02 05:32
No 381044
your links aren't working
(Chief Bee)
11-19-02 07:47
No 381080
If you ever want to download a PDF from me, and my links aren't working, go take a look in my PDF file depository at ../rhodium/pdf / - all the 100MB worth of interesting chemistry articles archived there can be accessed directly without any need for an explicit link.
(Hive Bee)
11-19-02 19:36
No 381265
Hey Rhodium, thanks for the tip. it's much appreciated.
(Hive Bee)
11-20-02 02:08
No 381414
so will nitrotoluene decarboxylate niacin and generate pyridine?