The Vespiary

The Hive => Newbee Forum => Topic started by: WHITE_DEVIL on November 19, 2002, 09:59:00 AM

Title: ethoxide question.
Post by: WHITE_DEVIL on November 19, 2002, 09:59:00 AM

sodium added to ethanol creates sodium ethoxide.
can this be done with any other alcohols?
Methanol?

Title: Yes
Post by: pHarmacist on November 19, 2002, 10:04:00 AM

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Title: Thanks is it possible to make 'sodium methoxide' ...
Post by: WHITE_DEVIL on November 19, 2002, 10:40:00 AM

Thanks
is it possible to make 'sodium methoxide' and use this turn say, 2,5 di bromo benzaldehyde to 2,5 dimethoxy benzaldehyde (+ 2NaBr)
Also can this be done with other group 1 metals such as Li?

Title: No
Post by: pHarmacist on November 19, 2002, 10:58:00 AM

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Title: Ethoxides....
Post by: Kreist on November 19, 2002, 11:07:00 AM

are used for transethylation of ester groups. Free hydroxy groups will not be methylated. Maybe you could use a quartenary ammonium salt for that?

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Title: And there is sodium isopropoxide aswell
Post by: raffike on November 19, 2002, 02:56:00 PM

And there is sodium isopropoxide aswell

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Title: The reaction is valid, but with some modifications
Post by: Rhodium on November 19, 2002, 04:08:00 PM

You could protect the aldehyde function of 2,5-dibromobenzaldehyde as the acetal, then react it with an excess of sodium methoxide in methanol using a catalytic amount of Copper(I)bromide, followed by hydrolysis of the acetal to get 2,5-dimethoxybenzaldehyde.

Both instructions for acetal formation and methoxylation can be found at my page, but exemplified for 3,4,5-trimethoxybenzaldehyde and 5-bromovanillin respectively.