pyridine

[UTFSE]

Is a desirable but rather scarce chem.

If one started with say niacin would it be possible to remove the hydroxycarbon (guessing) group from the pyridine ring?

Would this process be termed dehydroxy-carbonation?

And what generally method might one look for?
OTEECEE & meeeee!!!!

[fractal]

To decarboxylate niacin, you'll need an enzyme.  There might be a way to do it with some really obscure lead compound, but if you could buy that, you'd could probably buy pyridine, too.  Though again, if you can get an enzyme for decarboxylating niacin, you'll probably have access to pyridine as well...  But look into it.  Perhaps one of the useful enzymes is easy to procure...

[alchemy_bee]

Are there any street applicable synths for this?
Can a bee be visa vis its entity when half a bee philosophically must ipso facto half not be?

[UTFSE]

I have been   looking and looking and looking

er- did I mention I been LOOKING for a pyridine route for a long time

the web, the hive, deja, patents, journals, refs, etc etc etc. and all no viable   (note the word "viable" )methodology as yet.

so an enzyme eh? 
OTEECEE & meeeee!!!!

[quantum]

Pyridoxine was discovered in the 1930s as the result of a series of nutritional investigations of rats fed vitamin-free diets. The original compound that was isolated is pyridoxine, named due to its structural similarity with pyridine, but possessing an additional hydroxymethyl group in the para position. In the body, however, the parahydroxymethyl moietyis oxidized to an aldehyde and the similar group in the meta position is phosphorylated, resulting in the biologically active pyridoxal phosphate. This coenzyme is remarkably versatile, being involved in transaminations, decarboxylations, racemizations, and numerous modifications of amino acid side chains. Clinically, pyridoxine helps normal function of the brain, promotes blood cell formation, maintains the chemical balance among body fluids, and assists in carbohydrate, protein, and fat metabolism. Common sources of pyridoxine include bananas, carrots, nuts, rice, fish, soybeans, and wheat germ. Symptoms of pyridoxine deficiency are very non-specific and hard to reproduce.

wonder if ya could kick the hydroxymethyl group to make
pyridine
fucked if I know how but I am sure some one would here.

remeber its not about the drugs mate its about the music
ye right

[Osmium]

Pyridine from vitamins/enzymes??? How economical.  
I'm not fat just horizontally disproportionate.

[SPISSHAK]

I have a vague awnswer, to your quest.
Decarboxylation of B-6 via the copper quinoline complex.
But why bother, just go and buy the stuff say your using it for a flavoring agent or something like that.
From what I know ( not much ) copper sulphate/quinoline complex and facilitate a thermal decarboylation of B-6 to pyridine.

[lugh]

Synthesizing pyridine doesn't necessarily involve such expensive materials, it has been prepared by the distillation of nicotinic acid with lime, is present in bone oil and coal tar, and can be prepared by reacting hydrogen cyanide or ammonia with acetylene {Ber. 50 422 (1917)} or acetaldehyde with ammonia  

[halfapint]

Lugh, I like your post best of all this thread. I didn't think that this particular decarboxylation was as hard as people were saying, so it's comforting to see confirmation on this point. Those syntheses do deserve attention; the way you say it, makes it sound easy.

By a strange quirk of fate, some repressive regime has evidently turned Vitamin B-6 (!) into a watched chemical. It's hard to know how seriously to take this, but that's on the books about nicotinic acid, and one must stay alert to the most remote possibilities of exposure. It has been distasteful to contemplate the terribly hazardous extraction and hydrolysis of nicotine from cigars to obtain this reagent, so the synthetic pathways you mention look very appealing.
a half a pints a half a pound a half a world a half a round
Sidearm n. Flask neck tube.

[lugh]

SWIL often encounters difficulties in synthesis, but SWIL likes to work out such problems.

Patent GB534494

should prove of interest    A search for Tschitschibabin's German patents may also be fruitful  

[SPISSHAK]

I`ve heard about this somewhere too it forms a calcium salt of the carboxylic acid which can then be pyrollitically decarboxylated.
Don`t know where the reference is though could you provide a little detail?

[lugh]

Distillation of organic bases is a general method for the preparation of pyridines; distillation of any of the carboxylic acids of pyridine yields pyridine. Perhaps the most bee friendly synthesis would be to react glycerol with anhydrous magnesium sulfate to obtain acrolein, react that with ammonia to obtain acrolein-ammonia, distill that to obtain picoline, then distill the picoline (a carboxylic acid of pyridine) with lime to obtain pyridine. Further information may be found in Ann 241 1 (1887)  

[SPISSHAK]

B-6 sounds like it would do the same job.
as the picoline your`e talking about.

[lugh]

Yes, nicotinic acid is another carboxylic acid of pyridine, but the decarboxylation of picoline proceeds far faster than that of nicotinic acid, thus the preparation outlined above is the easiest, and OTC as well