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Topic: Alcohols to amines (hydroxyl to amino) with sodium amide  (Read 21294 times)

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Offline Will

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Alcohols to amines (hydroxyl to amino) with sodium amide
« on: December 16, 2005, 04:00:37 PM »
I have tried to search for an answer in google and on Chemical Forums so I apologise if it has already been answered!

I was wondering if it is possible to substitute the hydroxyl group with an amino group with sodium amide (NaNH2) in NH3(l). I know that it is done industrially with NH3(g) at 300-400oC with alumina (Al2O3) catalyst.

If it is possible to do it with sodium amide then what would be the conditions?

Thanks

Will

PS I don't intend to do this in the lab! Just wanted to know if it is possible.
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laotree

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Re:Alcohols to amines (hydroxyl to amino) with sodium amide
« Reply #1 on: December 16, 2005, 10:00:53 PM »
No. Hydroxyl group is not a good leaving group under the condition you described. Hydroxyl group could become a good leaving group in Mitsnobu condition or acidic condition.
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Offline Albert

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Re:Alcohols to amines (hydroxyl to amino) with sodium amide
« Reply #2 on: December 17, 2005, 06:10:05 AM »
If I were you, will17, I'd use MeOSOCl in order to obtain an excellent leaving group in 'standard' conditions (I hope you to understand what I mean).
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Offline Will

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Re:Alcohols to amines (hydroxyl to amino) with sodium amide
« Reply #3 on: December 26, 2005, 05:07:07 PM »
Thanks for the helpful replies- I really enjoyed reading up about the Mitsunobu reaction which I have never heard of before. I am somewhat doubtful about acidic conditions helping since sodium amide is very reactive.

Sorry, but I have no idea about the CH3OSOCl! I don't even know which of the two possible structures it is. Please could you explain this :)?

Any more suggestions on whether it is possible to do this reaction with sodium amide under ANY conditions are welcome!

Hope everyone had a great Christmas/Hanukkah.
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Offline Albert

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Re:Alcohols to amines (hydroxyl to amino) with sodium amide
« Reply #4 on: December 26, 2005, 05:40:13 PM »
Quote from: will17 on December 26, 2005, 05:07:07 PM
have no idea about the CH3OSOCl! I don't even know which of the two possible structures it is. Please could you explain this :)?

CH3SO2Cl is an extremely common reagent especially in the syntheses of drugs (to be frank with you, I'm almost fed up with it :D): if you're curious, I can show an example.
It is used for providing an excellent leaving group (the red one) in SN2 reactions involving alcoholic functions.
« Last Edit: December 26, 2005, 05:41:29 PM by Albert »
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Offline Albert

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Re:Alcohols to amines (hydroxyl to amino) with sodium amide
« Reply #5 on: December 26, 2005, 05:54:59 PM »
Oh, and thanks to MeSO2Cl, I think you might use even NH3 as reactant.
« Last Edit: December 26, 2005, 05:55:16 PM by Albert »
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Offline Will

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Re:Alcohols to amines (hydroxyl to amino) with sodium amide
« Reply #6 on: December 26, 2005, 06:29:39 PM »
Thanks for explaining that! The A-level syllabus is really bad, not that this is at all relevant to it- I just like teaching my teachers  ;D!

Would this have to be a two step process, since the HCl(g) produced would react with the ammonia? Also, what solvent would you use?

Thanks again for your help. ;)
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Offline Albert

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Re:Alcohols to amines (hydroxyl to amino) with sodium amide
« Reply #7 on: December 27, 2005, 02:26:57 AM »
HCl is generally neutralized by adding a certain quantity of pyridine.
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Offline Will

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Re:Alcohols to amines (hydroxyl to amino) with sodium amide
« Reply #8 on: December 27, 2005, 12:22:43 PM »
Thanks! It makes sense, but could you use NaNH2 after the CH3SO2Cl has done its bit, not NH3?
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Offline Albert

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Re:Alcohols to amines (hydroxyl to amino) with sodium amide
« Reply #9 on: December 27, 2005, 01:03:53 PM »
Of course! In fact, NaNH2 is a stronger nuclephile if compared with NH3 (which is 'only' more common).
Moreover I was just wondering whether you could use NH3.

So, generally speaking, NaNH2 is better than NH3. :D
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Offline HP

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Re:Alcohols to amines (hydroxyl to amino) with sodium amide
« Reply #10 on: December 27, 2005, 01:16:43 PM »
I was wondering if possible the group R-OSO2CH3 to be transformed to R-COOH by reaction with HCOOH?
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Offline Albert

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Re:Alcohols to amines (hydroxyl to amino) with sodium amide
« Reply #11 on: December 27, 2005, 01:41:35 PM »
AH AH AH! ;D lol

You're in love with HCOOH, aren't you? ;)

No, I don't think so. Try CO2.

Following your pathway you could come across an ester(maybe with the help of NaH), I guess. By the way, I think formic acid to be a too weak nucleophile to react the way you think.
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Offline ksr985

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Re:Alcohols to amines (hydroxyl to amino) with sodium amide
« Reply #12 on: December 27, 2005, 02:12:27 PM »
there are quite a few reagents you can use to make -OH a good leaving group. aside from MeSO2Cl, you can use the tosylate or triflate groups, like in the modified beckmann rearrangements .. these reagents are also quite common.
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i remain, always,
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Offline HP

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Re:Alcohols to amines (hydroxyl to amino) with sodium amide
« Reply #13 on: December 28, 2005, 11:54:59 AM »
Hehe you right great in love with HCOOH :-*
May be you right this reaction not possible as i think..By the way please tell me how CO2 could work with mesylate or tosylate derivative?
Now on the topic: Another god leaving group for OH- to NH2 transformation is p-nitrophenyl carbonate intermediat then NH3 autoclave or NaNH2 rt. Theres some procedure and with hydrazine...
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Offline Albert

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Re:Alcohols to amines (hydroxyl to amino) with sodium amide
« Reply #14 on: December 28, 2005, 01:04:20 PM »
Neither can CO2 serve as a source of COOH-groups (according to what I know), I was just kidding, sorry. ;D

Quote from: HP on December 27, 2005, 01:16:43 PM
I was wondering if possible the group R-OSO2CH3 to be transformed to R-COOH by reaction with HCOOH?

However, here is a present for you (not too late for Christmas, I hope).
Ok, this is not the reaction you were thinking about, but is an uncommon, useful (epirubicine is an anti-tumoral, industrially synthesized from daunomycine) and quite unpredictable reaction involving a derivative of your beloved formic acid.
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