DrNoiZeZ
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2,5-dimethoxyacetophenone reduction
I am planning to reduce the 2,5-dimethoxyacetophenone
As I coulld notice the method using Hydrazine does not give good yelds.
Does anyone has experience in using Clemmensen?
I tried Clemmensen with the 2,5-dihydroxyacetophenone and the results were not good (at least 4 products by HPLC)
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solo
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Reference Schematic
2,5-dimethoxyacetophenone
.....not exactly clemenson but ,
"The synthesis has proceeded from 2,5-dimethoxyacetophenone by the addition of a methyl group to the carbonyl followed by reduction to the
hydrocarbon. Aldehyde formation, nitropropene synthesis with nitroethane, and lithium aluminum hydride reduction are uneventful, providing the
hydrochloride salt DOIP, which has a mp of 183-184 °"
......source,
http://www.erowid.org/library/books_online/pihkal/pihkal071....
[Edited on 14-9-2011 by solo]
It's better to die on your feet, than live on your knees....Emiliano Zapata.
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DrNoiZeZ
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Ok very usefull thanks
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DrNoiZeZ
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After searching a little more, I tried Clemmensen again using only water (last time I used EtOH) and 36g of 2,5- dihydroxyacetophenone was reduced
very easily using the method I on Organic Reaction volume I page 164. I got, after freezing the filtrate, white crystals that was filtrated ( 22g
yield near 70% from literature). I was not able to get anything more from the liquid filtrated. I extracted it using Et2O (3x100ml) dried with MgSO4
and K2CO3 and after filtration the solvent was removed. The residue was heated and extracted with Hexane. The solution was freezed but que quantity of
crystals was less than 0,5g. The 10g left was junk.
Now I am planning to do HPLC to check the product.
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Nicodem
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If you invested at least five minutes in a literature search you would, not only found what you look for, but also found out that the correct product
of a Clemmensen reduction on 2,5-dimethoxybenzene is a liquid and not "white crystals". As the old saying goes: 5 minutes of searching the literature
can save you 5 hours of work in the lab.
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DrNoiZeZ
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That is not the point.
First I did not reduced 2,5-dimethoxybenzene because I am talking about 2,5 dihydroxyacetophenone and the product I want is ethylhydroquinone and as
far as I can know it must be a SOLID. There is no point reducing 2,5-dimethoxybenzene using Clemmensen. I tried first to reduce
2,5-dimethoxyacetophenone to get 2,5- dimethoxyethylbenzene (a liquid) but it was not good enough and I was forced to metilate 2,5
dihydroxyacetophenone first and since I use MeI to do so, it was very expensive, so I decided to do the reduction first and them metilate the product.
I search always and a lot the problem is that sometimes I just cannot find some publications and then I have no other choice than ask someone to help.
I think it is also the spirit of this forum - learn and help who wants to learn. Thanks for your attention anyway.
[Edited on 15-10-2011 by DrNoiZeZ]
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Nicodem
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Quote: Originally posted by DrNoiZeZ  | | First I did not reduced 2,5-dimethoxybenzene because I am talking about 2,5 dihydroxyacetophenone and the product I want is ethylhydroquinone and as
far as I can know it must be a SOLID. |
I apologize. I misread the name of the starting material, being mislead by the tread tittle and your first post.
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DrNoiZeZ
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no problem at all. I understand and you all are doing a great work. Thanks
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Satan
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Irony, did you ever heard about it?
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DrNoiZeZ
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no, I am not ironic, I really think it is not ease to control and help and give order on a site like this. There are many people here: some knowing
more and others trying to learn sometimes knowning nothing and wanting to do things that could be dangerous... I think everybody here has some
responsibility and the Moderators more than anyone and I really know that Nicodem knows much more than I and he can make a mistake like everybody here
[Edited on 15-10-2011 by DrNoiZeZ]
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Mush
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2,5-dimethoxyacetophenone -> 1-Ethyl-2,5-dimethoxybenzene
2,5-dimethoxyacetophenone -> 1-Ethyl-2,5-dimethoxybenzene
By Clemmensen reduction
JOC Vol. 25, page 1245, (1960)
1-Ethyl-2,5-dimethoxybenzene -> 4-Ethyl-2,5-dimethoxybenzaldehyde
By a modification of the method of Rieche (Example 17)
us4000197
Attachment: 1-Ethyl-2,5-dimethoxybenzene.pdf (439kB)
This file has been downloaded 589 times
Attachment: patus4000197.pdf (616kB)
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