Chemical Forums
Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: darkdevil on December 18, 2013, 08:38:41 AM
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Hi, I tried to perform the following transetherification with the below conditions. But after 20hours I get a mixture of products. Can I do the transetherification with an aldehyde group present? What other better ways do you suggest so that can I get my product?
(https://www.chemicalforums.com/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FqGemQEa.png%3F1&hash=cbc7e76595907e03c0360df35fcade37b8d63aa4)
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Those sorts of conditions look more like acetalisation ones to me. ArOMe :rarrow: ArOH is usually done with things like BBr3 in my experience, but imagine that may play merry havoc with the aldehyde - is there any protecting group in Greene and Wuts (or equivalent) that is stable to this?
Do you have to start with the methoxy? The free phenol seems cheap enough, see e.g. http://www.sigmaaldrich.com/catalog/product/aldrich/h19808?lang=en®ion=GB
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I also wonder before if I shall use the phenol form to perform ullmann ether synthesis. I bought some already, but is it really no luck for the above reaction?
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BBr3 also gives some bro inaction of the benzene ring. As sjb suggested starting from the phenol is worth a go.
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What is bro inaction?
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I also wonder before if I shall use the phenol form to perform ullmann ether synthesis. I bought some already, but is it really no luck for the above reaction?
It's not really an Ullmann, though is it? (Isn't this 2RX :rarrow: RR ?), the acidity of the phenol should be such that you can just use NaH and alkyl halide I think.
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SJB,
I think so aswell
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What is bro inaction?
Damm spelling checker, I was on the iPad. It should be bromination, sorry.
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oops wrong thread...
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I also wonder before if I shall use the phenol form to perform ullmann ether synthesis. I bought some already, but is it really no luck for the above reaction?
It's not really an Ullmann, though is it? (Isn't this 2RX :rarrow: RR ?), the acidity of the phenol should be such that you can just use NaH and alkyl halide I think.
I have done many phenolic alkylations on large scale, >200kgs, the best is really potassium carbonate, alkyl halide, phenol in refluxing acetone. Methods I have on this computer.
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Disco,
That seems like a good reaction. Easy. The Ullmann I believe the OP was referring to is a condensation. Not the R-R type. Both use copper, but from what I have just read, the condensation is done at high temperatures and is a bit fickle.
And if you have done this on 200 kilos or more. Im taking that advice to the bank.
Thanks, now I get it. Bromination. I was reading and think I have never heard that term, bro inaction. Its all for a good laugh, no worries.
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I also wonder before if I shall use the phenol form to perform ullmann ether synthesis. I bought some already, but is it really no luck for the above reaction?
It's not really an Ullmann, though is it? (Isn't this 2RX :rarrow: RR ?), the acidity of the phenol should be such that you can just use NaH and alkyl halide I think.
I have done many phenolic alkylations on large scale, >200kgs, the best is really potassium carbonate, alkyl halide, phenol in refluxing acetone. Methods I have on this computer.
wow!! do u work in industries?? and does the condition you mentioned has good yield? would it affect the aldehyde group within? thank you so much all of you
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I think the aldehyde should be OK. Try it and see.
If it does not work protect it.
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Those sorts of conditions look more like acetalisation ones to me. ArOMe :rarrow: ArOH is usually done with things like BBr3 in my experience, but imagine that may play merry havoc with the aldehyde - is there any protecting group in Greene and Wuts (or equivalent) that is stable to this?
Do you have to start with the methoxy? The free phenol seems cheap enough, see e.g. http://www.sigmaaldrich.com/catalog/product/aldrich/h19808?lang=en®ion=GB
Finally, I tried to use the phenol form and performed Ullman type condensation with an alkyl bromide in DMF. The reaction worked well and nearly 100% yield. Thanks