Sciencemadness Discussion Board

Help for preparation of 2 benzylpyridine

Aqua-regia - 20-3-2012 at 10:41

2-benzylpyridine is a starting material for 2-(2,4-dinitrophenyl)pyridine. This is an interesting photochromic compound

http://courses.chem.psu.edu/chem36/Chem36H/IndivExpt1/440%20...

Can somebody tell my a way to obtain 2-benzylpyridinel from benzene + AlCl3 and suitable pyridinederivate

thanks!!

Chordate - 25-3-2012 at 16:25

What do you mean by suitable pyridine derivate? Choose a reaction scheme and then acquire the chemicals, not the other way around.

Dr.Bob - 26-3-2012 at 17:14

Quote: Originally posted by Aqua-regia  
2-benzylpyridine is a starting material for 2-(2,4-dinitrophenyl)pyridine. This is an interesting photochromic compound

http://courses.chem.psu.edu/chem36/Chem36H/IndivExpt1/440%20...

Can somebody tell my a way to obtain 2-benzylpyridinel from benzene + AlCl3 and suitable pyridinederivate

thanks!!


I can't understand a university lab naming the compound wrong, but the product would be 2-(2,4-dinitrobenzyl)pyridine, since the methylene group is still present. I would look at the J Chem Ed for the reference to the preparation of the SM. It will likely be there.

The simplest pyridine SM I have used is 2-chloropyridine, but I don't know if it would react with a benzyl halide or benzyl organometallic directly. You might be able to acylate benzene with 2-pyridinoyl chloride and then reduce the ketone away. I don't think 2-chloromethylpyridine would react with benzene in a Friedel Craft reaction, but you could look it up to see.

Bob

Aqua-regia - 27-3-2012 at 11:52

Hi Dr Bob and Chordate

I founded this patent , there is a reaction sheme but the matter is unfortunatelly in japanese language:
http://worldwide.espacenet.com/publicationDetails/biblio?DB=...

This is the next usable article, but I dont have access
http://pubs.acs.org/doi/abs/10.1021/ja01181a506

ScienceSquirrel - 28-3-2012 at 03:33

It looks like the patent details the reaction of chloromethylpyridine with benzene in the presence of aluminium chloride. I would expect this to be a fairly straight forward Friedel Crafts reaction.

Aqua-regia - 28-3-2012 at 09:41

Yes i realized, but is a hard way again. Not easy to get syntetically 2-chloromethylpiridine in home lab.

DJF90 - 28-3-2012 at 10:22

If you U2U me an email address I'll send you a couple papers for making the 2-benzylpyridine using compounds/reagents you should be able to get/make. If you're in the UK I might also be able to help you on that front also.

Dr.Bob - 29-3-2012 at 13:15

Look at the following to see the entire paper in JACS. It uses pyridine and benzyl chloride as the main reagents and copper as the catalyst. Those are about as simple of reagents that you could ask for. That is a pretty interesting way to do it.

See the links below to see the last 2 pages of the article. (or just hit the next button on the link above).

http://pubs.acs.org/doi/abs/10.1021/ja01181a507
http://pubs.acs.org/doi/abs/10.1021/ja01181a508

Aqua-regia - 30-3-2012 at 11:28

My referred paper above (http://pubs.acs.org/doi/abs/10.1021/ja01181a506) is the same. Thank you, it is really usable way. Disadvantage of this methode is the niggling of isomers.