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Topic: What happen when NaOH mix with MeOH?  (Read 7392 times)

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Offline Hand15

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What happen when NaOH mix with MeOH?
« on: July 14, 2008, 02:37:19 PM »
Not long ago I did some reaction involving terephthalic acid dimethyl ester (dimethyl terephthalate). It involves addition of NaOH/MeOH mixture to the solution of dimethyl terephthalate/Acetone. My senior said it will hydrolize.

I wonder why it will hydrolize, there aren't even any water used and it was done in room temperature (if I'm not wrong, hydrolysis is done in aqueous base and is heated).

Is there something to do with the NaOH dissolved in MeOH?
Base of my observation, the solvation is exothermic. I guess it forms some sort of methoxide, but it is irrelevant considering the transesterification would produce the same compound.
 ??? ???
Dimethyl terephthalate:




Offline Rico

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Re: What happen when NaOH mix with MeOH?
« Reply #1 on: July 14, 2008, 07:59:10 PM »
Hey Hand15

It is true that the first step in the hydrolysis is an equilibrium step and after hydrolysis it could just as well revert back to starting materials. The thing here is that a subsequent step will drive the hydrolysis reaction (see jpeg attached). Once the acid is formed, the formed methoxide ions will deprotonate the acid instantly forming the stable carboxylate salt.

I hope this answered your question

Rico

Offline Hapto

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Re: What happen when NaOH mix with MeOH?
« Reply #2 on: July 22, 2008, 05:13:41 PM »
No, it shouldn't hydrolyze if the methanol was dry and the NaOH is present in catalytic amounts.  You do have acetone in there.  What do you think would happen to acetone in the presence of strong base and methanol?


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