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Topic: Alcohols to amines (hydroxyl to amino) with sodium amide  (Read 21291 times)

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Offline HP

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Re:Alcohols to amines (hydroxyl to amino) with sodium amide
« Reply #15 on: December 28, 2005, 01:39:21 PM »
Nice present thank you :) Actinomicine group antibiotics are really interesting but and quite a toxic one.. anyway this synthetic example much excited me. Mechanism is some unclear but it seems i should learn much about my beloved ;)
CO2 may be used for very efficient conversion Grignards to COOH as follows:
R-X + Mg---> R-MgX
R-MgX + CO2dry---> RCOOMgX
RCOOMgX + HCl---> R-COOH
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Offline Albert

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Re:Alcohols to amines (hydroxyl to amino) with sodium amide
« Reply #16 on: December 28, 2005, 01:53:52 PM »
CO2 may be used for very efficient conversion Grignards to COOH as follows:
R-X + Mg---> R-MgX
R-MgX + CO2dry---> RCOOMgX
RCOOMgX + HCl---> R-COOH

Yes, I know. But YOU wondered about ROSO2Cl. However, I think this doesn't have anything to do with this topic.

Offline HP

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Re:Alcohols to amines (hydroxyl to amino) with sodium amide
« Reply #17 on: December 28, 2005, 02:58:08 PM »
Here what i found for conversion OH to NH2 by variant of Staudinger reaction:
"Treatment of alcohols with NaN3 and two equivalents of PPh3 in CCl4-DMF(1:4) at 90°C afforded amines in an excellent yields (85-95%). Formation of amines may be visualized as the initial azide formed would react with second equivalent of Ph3P giving the iminophosphorane which in turn converted to the amine upon treatment with water."
Here used Na-azide do you think using NaNH2/PPh3 may lead to direct substitution OH ???
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Offline Will

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Re:Alcohols to amines (hydroxyl to amino) with sodium amide
« Reply #18 on: December 28, 2005, 03:20:45 PM »
Thanks for suggesting that- it would be great to hear from someone if they think that might work. I finally found out, from a decent source, about the Mitsunobu reaction, which laotree suggested. This uses Ph3P and DEAD, but suggests the nucleophile should be HNu, do you think NaNu ie. NaNH2 would work?

Offline Albert

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Re:Alcohols to amines (hydroxyl to amino) with sodium amide
« Reply #19 on: December 28, 2005, 03:23:00 PM »
do you think using NaNH2/PPh3 may lead to direct substitution OH ???

I don't think so.

Offline HP

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Re:Alcohols to amines (hydroxyl to amino) with sodium amide
« Reply #20 on: December 28, 2005, 03:30:05 PM »
He he NH3 gas i see, but may be in pressure conditions at closed system;)
I am not very fammiliar with nucleophility NaN3 in comparison NaNH2 but is stupid to write:
R-OH + NaN3-->reverse R-O:-Na+ HN3
HN3--> how decompose: hope no "bum!"  :)
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Offline HP

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Re:Alcohols to amines (hydroxyl to amino) with sodium amide
« Reply #21 on: December 28, 2005, 03:35:37 PM »
Make significant supplimentment:
Reaction ROH with NaN3/PPh3 in and with CBr4 as sourse of Br for first conversion R-OH to R-Br and after that R-Br + NaN3 and so on and so on...
You should agree R-Br may react with NaNH2 pretty nice  :P
Nice discussion friends!
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Offline Albert

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Re:Alcohols to amines (hydroxyl to amino) with sodium amide
« Reply #22 on: December 28, 2005, 03:51:49 PM »
Ok, if you don't want to use MeSO2Cl, use HBr (Br2 in conc. AcOH).
Then add NaN3 to your R-Br: it's an SN2 reaction.
Final step consists in a catalytic hydrogenation with H2/Pd.

It's always my pleasure.

Offline jdurg

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Re:Alcohols to amines (hydroxyl to amino) with sodium amide
« Reply #23 on: December 28, 2005, 11:04:09 PM »
He he NH3 gas i see, but may be in pressure conditions at closed system;)
I am not very fammiliar with nucleophility NaN3 in comparison NaNH2 but is stupid to write:
R-OH + NaN3-->reverse R-O:-Na+ HN3
HN3--> how decompose: hope no "bum!"  :)


HN3 is a NASTY little compound that I believe outranks HCN in terms of its ability to kill you.  It's fairly unstable too, as are all azides, and will tend to decompose into hydrogen gas and nitrogen gas.  As long as you have good ventillation, I don't think enough of it will build up to cause an explosion hazard, but it also doesn't take very much to kill you if you breathe it in.
"A real fart is beefy, has a density greater than or equal to the air surrounding it, consists

Offline HP

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Re:Alcohols to amines (hydroxyl to amino) with sodium amide
« Reply #24 on: December 29, 2005, 12:39:19 PM »
HN3 very toxic and hazardous compound i agree. Please everyone be very carefull in working with it. I know many methal azides are high explosive such as Ag and Pb-azides  used to initiate explosion of Nobel's dinamite.
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