[bmthog]

Please help me, how to prepare 2-ethylpyridine from pyrindine?

I think EtLi can react directly with pyridine to form 2-ethylpyridine, can't it?

[discodermolide]

Please help me, how to prepare 2-ethylpyridine from pyrindine?

I think EtLi can react directly with pyridine to form 2-ethylpyridine, can't it?

Ethyllithium will not substitute for hydrogen at any position of the pyridine ring.

[bmthog]

So how to prepare 2-ethylpyridine from pyrindine?
Tks in advance

[discodermolide]

So how to prepare 2-ethylpyridine from pyrindine?
Tks in advance

Well, do you have any ideas? Forum rules require you to have made an effort. This so we can see your thinking and gently push you in the right direction if required.

[bmthog]

I suggest pyridine react with acetaldehyde/ OH^-

2-CH₂CHO-C₅H₅N reduce with Zn(Hg)/HCl to form 2-ethylpyridine.?

[discodermolide]

I suggest pyridine react with acetaldehyde/ OH^-

2-CH₂CHO-C₅H₅N reduce with Zn(Hg)/HCl to form 2-ethylpyridine.?

Perhaps one could start from the pyridone? Or picoline (2-methylpyridine). Or even pyridine.
have a look at this link.

http://131.104.156.23/Lectures/7113/7113_Literature/FMC%20Lithium%20pdf/Pyridines.pdf

[orgopete]

Please help me, how to prepare 2-ethylpyridine from pyrindine?

I think EtLi can react directly with pyridine to form 2-ethylpyridine, can't it?

I am guessing this reaction was presented in your class or your textbook. It is shown in Scheme 1 of the reference linked by discodermolide. Obviously, it gives a dihydropyridine product and would need re-aromatization. You may also react an alpha-halopyridine, chloro or better fluoro with an ethyllithium which can eliminate to give your desired product, but this reaction may not have been covered in your textbook.

[bmthog]

How to substitute halogen at alpha-position of pyridine? if you S_E it only substitute at beta-position

I suggest pyridine react with acetaldehyde/ OH^-

2-CH₂CHO-C₅H₅N reduce with Zn(Hg)/HCl to form 2-ethylpyridine.?

How about this way, is it possible?

[discodermolide]

How to substitute halogen at alpha-position of pyridine? if you S_E it only substitute at beta-position

I suggest pyridine react with acetaldehyde/ OH^-

2-CH₂CHO-C₅H₅N reduce with Zn(Hg)/HCl to form 2-ethylpyridine.?

How about this way, is it possible?

You will need a stronger base than OH^- to do this. I think the product will then eliminate to give the olefin. Which you can try and hydrogenate to your product.
Did you look at the link I provided above?

[bmthog]

I suggest another way:
Pyridine---> Pyridine N-oxide + KCN/MeOH ----> 2-cyanopyridine ---1) H2O2 2) CH3Cl---> 2-ethylpyridine.
Is it feasible?

[discodermolide]

I suggest another way:
Pyridine---> Pyridine N-oxide + KCN/MeOH ----> 2-cyanopyridine ---1) H2O2 2) CH3Cl---> 2-ethylpyridine.
Is it feasible?

Anything is feasible, the question is, is it correct?
What are you aiming for by treating cyanopyridine with H₂O₂ and then chloroform? I think something is missing here.
I don't see a reductive step to regenerate the pyridine from the N-oxide.

[bmthog]

I see this reaction in page 6.
https://docs.google.com/viewer?a=v&pid=gmail&attid=0.1&thid=137d962638910944&mt=application/pdf&url=https://mail.google.com/mail/?ui%3D2%26ik%3D235fc9b158%26view%3Datt%26th%3D137d962638910944%26attid%3D0.1%26disp%3Dsafe%26realattid%3Df_h3axeooc0%26zw&sig=AHIEtbTca3f7Hb_bkzGcwdnyKKvwoHQJVA

[discodermolide]

I see this reaction in page 6.
https://docs.google.com/viewer?a=v&pid=gmail&attid=0.1&thid=137d962638910944&mt=application/pdf&url=https://mail.google.com/mail/?ui%3D2%26ik%3D235fc9b158%26view%3Datt%26th%3D137d962638910944%26attid%3D0.1%26disp%3Dsafe%26realattid%3Df_h3axeooc0%26zw&sig=AHIEtbTca3f7Hb_bkzGcwdnyKKvwoHQJVA

Sorry that link does not work for me.
Why not react ethyl lithium directly with pyridine N-oxide, Grignards react as well, as you require, use ethyl Grignard!
Have a look here towards the bottom of the page.

http://www2.chemistry.msu.edu/faculty/reusch/virttxtjml/heterocy.htm

[bmthog]

Wonderful, tks u so much discodermolide :X

[discodermolide]

Wonderful, tks u so much discodermolide :X

No problem