Chemical Forums
Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: Rookie_OC_Lover on June 23, 2013, 07:33:53 PM
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hi,
Anyone knows how this reaction is done ?
Kinetics/catalyst/anything would be greatly appreciated. anything.
thou i don't think it's a One-Product-Yielding reaction, but this is all i got from a website.
Any other way you know to make this product, i'm here to hear about.
Please help me to make this compound : 3-BromoPropanal
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You need to form an enolate of acetaldehyde with a strong base which reacts with your dibromomethane.
Probably using NaOH would work but you will most likely get a mixture of products. Maybe LDA would be better but this is much harder to work with.
The issue is that the acetaldehyde enolate will react with acetaldehyde and it will also react with your product so you want something strong enough to deprotonate the aldehyde and keep it deprotonated.
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Do you know any other ways to make the product? any guess or something.
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http://www.sigmaaldrich.com/catalog/product/aldrich/167169?lang=en®ion=GB
Oxidation of 3-bromopropanol with PCC in DCM.
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@OP, It is best if you show your attempt first, before asking for help.
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@OP, It is best if you show your attempt first, before asking for help.
funny, I am asking how to attempt it.
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Do you have a specific molecule which is your starting point? Or you just need to prepare 3-BromoPropanal and doesnt matter how?
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@OP, It is best if you show your attempt first, before asking for help.
funny, I am asking how to attempt it.
Showing your attempt at a problem first is a rule of this forum. Showing your attempt might be broadly interpreted to mean what papers have you read on the subject, or what types of scientific searching did you do. Is this a homework problem, or is this a research assignment of some sort? If the latter, why is it necessary to start with the compounds you did?
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Do you have a specific molecule which is your starting point? Or you just need to prepare 3-BromoPropanal and doesnt matter how?
No, I need to prepare 3-BromoPropanal by any way possible.
Is this a homework problem, or is this a research assignment of some sort? If the latter, why is it necessary to start with the compounds you did?
I want to use it in one step of my multi-step synthesis.
it will be reacted with Phenylhydrazine to yield an indole with bromomethane being at C3 of indole.
No, not a homework.
BTW, thank you all for your answers.
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Can you think of a route that involves reduction? I am not saying that this would better than the route involving oxidation.
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Could you brominate indole-3-carbinol with PBr3?
http://www.sigmaaldrich.com/catalog/product/sigma/i7256?lang=en®ion=GB
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Can you think of a route that involves reduction? I am not saying that this would better than the route involving oxidation.
Reducing what ?
like turning 3-Bromo-1-iodo-Propane to the desired aldehyde ?
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The SN2 of the Fischer indole synthesis may competitively react at the Br via your proposed route.
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Could you brominate indole-3-carbinol with PBr3?
http://www.sigmaaldrich.com/catalog/product/sigma/i7256?lang=en®ion=GB
don't know whether it works or not, but as you may know indole is more reactive at C3 and by that being substituted, other carbons on benzene ring get more willing toward bomination.
tha's why i don't consider the starting with indole. but more preferably i wanna synthesis indole with bromine being in its desired position.
tnx
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PBr3 will be selective towards the alcohol rather than the aromatic carbons.
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my final(not final really) product is going to be the attached image .
I wouldn't care if the blue marked hydrogen gets replaced by the following groups:
CN, OH, COOH, SH
the red marked H is what i emphasize to be intact.
Tnx
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PBr3 will be selective towards the alcohol rather than the aromatic carbons.
Having said that there may be competition with the C3 if the reaction with PBr3 is SN1 rather than SN2.
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Having said that there may be competition with the C3 if the reaction with PBr3 is SN1 rather than SN2.
Would you please explain why do you think Sn1 should be considered to happen ?
OH group in indole-3-carbinol isn't a good leaving group. (unless we force it)
or maybe i'm not taking some stuff into account ???
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Can you think of a route that involves reduction? I am not saying that this would better than the route involving oxidation.
Reducing what ?
like turning 3-Bromo-1-iodo-Propane to the desired aldehyde ?
I was thinking of reducing an acid to the aldehyde. We had a nice discussion about this transformation on a thread here a few weeks ago. I can see that it might take two steps*. Why don't you write it out?
*or three.
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We had a nice discussion about this transformation on a thread here a few weeks ago.
can you give me that forum name or address.
Tnx agn
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We had a nice discussion about this transformation on a thread here a few weeks ago.
can you give me that forum name or address.
Tnx agn
By typing "aldehyde" into the search function here, I found: http://www.chemicalforums.com/index.php?topic=67874.0
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Having said that there may be competition with the C3 if the reaction with PBr3 is SN1 rather than SN2.
Would you please explain why do you think Sn1 should be considered to happen ?
OH group in indole-3-carbinol isn't a good leaving group. (unless we force it)
or maybe i'm not taking some stuff into account ???
If the hydroxyl is protonated then the resonance structure of the carbocation would be relatively stable. although thinking about it the attack would be on C2 rather than C3. I am not saying that it would happen just that some might.
You see the thing with synthesis is that you need to experiment and find which route gives the highest yield or the fewest side reactions.
Best of luck whichever route you choose.
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You see the thing with synthesis is that you need to experiment and find which route gives the highest yield or the fewest side reactions.
True, but a lit search is in order here. The transformations being discussed (formation and bromination of that indole C-3 hydroxymethyl) are known and have already been reported.
It all works but you'll have to protect the nitrogen, of course.
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The transformations being discussed (formation and bromination of that indole C-3 hydroxymethyl) are known and have already been reported.
It all works but you'll have to protect the nitrogen, of course.
is it reported ? where ? any papers on it ?
thanks a lot friends.