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Author: Subject: 1-propanol from 2-propanol
reactofurnace
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[*] posted on 22-6-2019 at 19:20
1-propanol from 2-propanol


Guys I'm trying to make 1-propanol for a simple oxidition reaction to yield propanoic acid.

I have a plentiful supply of 2-propanol so i was wondering if there is a reasonable way to make n propanol from it.
If theres other starting points thats okay as well.

From what i have research is possible to do a dehydration of 2-propanol to give propene. this then would undergo an electrophillic addition with HBr under benzoyl peroxide to give 1 bromopropane. after a simple nucleophillic substitution is done with hydroxide to form the alcohol.
This pathway seemed reasonable but i'm not sure what conditions are required for the electrophillic addition. Can you use hydrobromic acid? also im not sure how to introduce the benzoyl peroxide.

Help? anyone :)

[Edited on 23-6-2019 by reactofurnace]
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Metacelsus
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[*] posted on 23-6-2019 at 01:10


If you're after propanoic acid, it's probably easier to make it by haloform reaction of 2-butanone (methyl ethyl ketone).

Keep in mind propene is a gas, and therefore somewhat difficult to work with.




As below, so above.
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DavidJR
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[*] posted on 23-6-2019 at 07:23


No, there is not a 'reasonable' way to turn 2-propanol into 1-propanol. Can it be done? Yes. But at great cost for a substance which is available cheaply as a solvent.

Also, propene gas is available OTC in "MAPP gas alternative" products for blowtorches (though sometimes mixed with other gases like methylacetylene, propane, propadiene, dimethyl ether - but if you look around you can get brands that are pure propene)

[Edited on 23-6-2019 by DavidJR]
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Keras
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[*] posted on 23-6-2019 at 07:33


Quote: Originally posted by reactofurnace  
Guys I'm trying to make 1-propanol for a simple oxidition reaction to yield propanoic acid.

I have a plentiful supply of 2-propanol so i was wondering if there is a reasonable way to make n propanol from it.
If theres other starting points thats okay as well.

From what i have research is possible to do a dehydration of 2-propanol to give propene. this then would undergo an electrophillic addition with HBr under benzoyl peroxide to give 1 bromopropane. after a simple nucleophillic substitution is done with hydroxide to form the alcohol. [Edited on 23-6-2019 by reactofurnace]


As someone noticed, propene is a gas at r.t. so you'd have to bubble it in a solution of HBr and benzoyl peroxide. I suppose the latter is here to promote the formation of Br• radicals which result in an anti-Markovnikov addition on the double bond, precisely what you're after.

Alternatively, why don't you mix propene with bromine gas outside during a sunny day? Ok, dealing with bromine is delicate, but dealing with peroxide is risky, too.
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Metacelsus
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[*] posted on 23-6-2019 at 09:20


Quote: Originally posted by Keras  

Alternatively, why don't you mix propene with bromine gas outside during a sunny day? Ok, dealing with bromine is delicate, but dealing with peroxide is risky, too.


That would produce 1,2-dibromopropane. Not super useful for propanoic acid production.




As below, so above.
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clearly_not_atara
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[*] posted on 23-6-2019 at 09:31


Pinacol rearrangement of propylene glycol to propionaldehyde is possible in decent yield according to several patents. Often this is a gas-phase flow reaction using a heated tube. Reduction of propionaldehyde is not too hard afaik.



[Edited on 04-20-1969 by clearly_not_atara]
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Keras
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[*] posted on 23-6-2019 at 22:01


Quote: Originally posted by Metacelsus  
Quote: Originally posted by Keras  

Alternatively, why don't you mix propene with bromine gas outside during a sunny day? Ok, dealing with bromine is delicate, but dealing with peroxide is risky, too.


That would produce 1,2-dibromopropane. Not super useful for propanoic acid production.


Sure, sorry, I meant HBr gas, that you can boil off an azeotropic hydrobromic acid solution. Though you'd probably still end up with a mix between 1-bromopropane and 1,2-dibromopropane.

Sorry for the mistake! :)
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draculic acid69
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[*] posted on 24-6-2019 at 00:35


You'd need to oxidise the propionaldehyde not reduce it.
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