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Topic: Synthesis of mono acyl-chloride of mono-benzyl dicarboxylic acid ester  (Read 16579 times)

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Offline Cultivator

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Re: Synthesis of mono acyl-chloride of mono-benzyl dicarboxylic acid ester
« Reply #15 on: August 31, 2009, 05:53:41 PM »
True, true.

Offline Cultivator

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Re: Synthesis of mono acyl-chloride of mono-benzyl dicarboxylic acid ester
« Reply #16 on: August 31, 2009, 06:03:40 PM »
Ok, now tell me this thing.
One pot chemistry with acyl chloride, is it possible? I've seen some procedures, where it is claimed that it's possible to inject the second reagent into the reaction when thionyl chloride is still there, in the reaction medium, in order to have the acyl chloride reacting with the next reagent in the same medium. I did not see any clear statements about it.

What considerations, in your opinion, should be done, in order to obtain a final product of acyl chloride condensation with something, in one reaction step?


Offline Sam (NG)

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Re: Synthesis of mono acyl-chloride of mono-benzyl dicarboxylic acid ester
« Reply #17 on: August 31, 2009, 06:43:48 PM »
If you put an alcohol in with thionyl chloride, especially if there is base in the reaction, you'll form the corresponding alkyl chloride.

The only way that you might be able to do it is if you used 1:1:1 thionyl chloride:acid:alcohol and reacted the acid and thionyl chloride for a few hours then added the alcohol to the mix.

Here would be my advice:

Use triethylamine, a low boiling solvent and thionyl chloride for the first step, don't heat your reaction over 75 degrees.  After a few hours, distill off the excess solvent, thionyl chloride and triethylamine under vacuum on a Schlenk line, leaving your acid chloride, then add in your alcohol in an appropriate solvent and finally some more triethylamine to get things going.

Offline blind

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Re: Synthesis of mono acyl-chloride of mono-benzyl dicarboxylic acid ester
« Reply #18 on: August 31, 2009, 11:07:44 PM »
Or just add an excess of alcohol, since everything else is easily filtered off or evaporated.

Offline Cultivator

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Re: Synthesis of mono acyl-chloride of mono-benzyl dicarboxylic acid ester
« Reply #19 on: September 01, 2009, 03:00:26 AM »
Thank you very much, people, this was very helpful  :)

What are those mole snacks and why do I have a -1? :)

Offline Cultivator

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Re: Synthesis of mono acyl-chloride of mono-benzyl dicarboxylic acid ester
« Reply #20 on: September 01, 2009, 01:05:49 PM »
Blind - it all depends on what alcohol we are talking about. Anything with OH here is considered an alcohol

Offline blind

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Re: Synthesis of mono acyl-chloride of mono-benzyl dicarboxylic acid ester
« Reply #21 on: September 01, 2009, 03:44:26 PM »
Yeah, but after you form your ester, what's left? SO2? Evaporates off.  Salt? Filter off.  Solvent? Rotovap.  Then you're left with running a column.

Offline Cultivator

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Re: Synthesis of mono acyl-chloride of mono-benzyl dicarboxylic acid ester
« Reply #22 on: September 03, 2009, 03:08:41 AM »
Yeah.. Running a column is the answer to all our problems. It is a good way to purify 5g of compound on a 500g silica (if not much more), but what about 1kg of compound to be purified?
Then, it is better (not related to the context of this thread), to try everything else besides column to purify, and column should, in my opinion, be the last move a chemist does to purify - only because it always works.

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