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Topic: About Henry Reaction  (Read 16763 times)

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Offline Nitrous_Acid

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Re: About Henry Reaction
« Reply #15 on: July 23, 2008, 11:25:47 AM »
So as a general rule can we say that "Make the reaction as non-harsh as possible before neutralizing the base to not to dehydrate your compound (to get Nitro-Alcohol) before neutralizing the base?"

I've re-asked the question because at Reply #11 I've mistakenly written the above text shown in bold twice and I wanted to be sure! because this Reaction is really very important to me! Do you understand me (and why I've re-asked) now?
« Last Edit: July 23, 2008, 11:39:51 AM by Nitrous_Acid »

Offline macman104

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Re: About Henry Reaction
« Reply #16 on: July 23, 2008, 12:30:00 PM »
So you want to know:

Make the reaction as non-harsh as possible before neutralizing the base to not to dehydrate your compound (to get Nitro-Alcohol) before neutralizing the base



The answer to this is yes.

Offline Nitrous_Acid

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Re: About Henry Reaction
« Reply #17 on: July 23, 2008, 01:43:11 PM »
No I want to know excatly:

Make the reaction as non-harsh as possible before neutralizing the base to not to dehydrate your compound (to get the Nitro-Alcohol)?
« Last Edit: July 23, 2008, 01:53:31 PM by Nitrous_Acid »

Offline azmanam

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Re: About Henry Reaction
« Reply #18 on: July 23, 2008, 02:09:18 PM »
What exact reaction are you trying to do.  Sometimes the base and temperature you choose will depend on other functional groups in the molecule.  Are you trying to make nitrostyrene? What's the next step in your synthesis?

A more nuanced answer can be given if you provide the exact transformation you are attempting.

(macman, will you PM me if you get a chance?)
Knowing why you got a question wrong is better than knowing that you got a question right.

Offline Nitrous_Acid

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Re: About Henry Reaction
« Reply #19 on: July 23, 2008, 02:52:54 PM »
I'm not trying to make any transformation. No next steps or whatsoever! I just need general information about Henry Reaction!

Offline macman104

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Re: About Henry Reaction
« Reply #20 on: July 23, 2008, 05:48:57 PM »
Does anyone else get the feeling of going around in circles here?  :-\

Offline Nitrous_Acid

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Re: About Henry Reaction
« Reply #21 on: July 23, 2008, 11:44:19 PM »
I need an absolute answer to my question:

Make the reaction as non-harsh as possible before neutralizing the base to not to dehydrate your compound (to get the Nitro-Alcohol)?

For example after the base has been neutralized and we isolate the Nitro-Alcohol in his pure form can we distill the Nitro-Alcohol without the risk of dehydration?
« Last Edit: July 24, 2008, 12:01:22 AM by Nitrous_Acid »

Offline macman104

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Re: About Henry Reaction
« Reply #22 on: July 24, 2008, 12:01:30 AM »
For your first question:  Yes

It's hard to say if the distillation will affect the compound or not.  Why don't you do a small scale distillation, and see what happens?  If you aren't working on something, why all the specifics?  Some of these things are too hard to determine without just trying it.

Offline Nitrous_Acid

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Re: About Henry Reaction
« Reply #23 on: July 24, 2008, 12:27:32 AM »
Now I'm reading at somewhere that Tertiary Amines are used as catalysts if we want a Nitro-Alcohol! Why is this? Can you explain this case to me?

Offline macman104

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Re: About Henry Reaction
« Reply #24 on: July 24, 2008, 12:29:24 AM »
Can you provide me with a link please to your information so I can read what you are reading?

Nvm, just read this link.  It provides the mechanism, and it shows where the base catalyst comes in.

http://www.organic-chemistry.org/namedreactions/henry-reaction.shtm

Offline Nitrous_Acid

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Re: About Henry Reaction
« Reply #25 on: July 24, 2008, 12:38:12 AM »
Org. Lett., 3 (20), 3075 -3078, 2001.

Offline Nitrous_Acid

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Re: About Henry Reaction
« Reply #26 on: July 24, 2008, 12:50:30 AM »
Yes I've observed that page also but I'm stuck at one point. Does the molecule get one of his Hydrogens from another molecule of Nitro-Alkane?

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