Sciencemadness Discussion Board

Possible routes for synthesis of esters of tertiary alcohols and phenols, using carboxylic acids

Cou - 19-4-2020 at 12:11

i would like to make esters from carboxylic acids since they can be oxidized from alcohols made in grignard reactions, giving many options to explore esters from several combinations of carboxylic acids and alcohols, millions of unique smells.


wg48temp9 - 20-4-2020 at 01:26

You forgot the boric acid method for phenols. Posted here only 9 days ago!

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Cou - 20-4-2020 at 19:43



he investigations of Béhal and other authors (loc. cit.) have led to the generally accepted view that the esterification of alcohols with the formic acid/acetic anhydride reaction mixture leads to the exclusive formation of formates. A reinvestigation, however, has shown that under the conditions used by Béhal, acetates are also produced. Generally, the amounts of acetates formed decrease in the order primary, secondary, tertiary alcohols; in the last case acetates are formed to a negligible degree. This finding leads to a simple and convenient method for the preparation of pure tertiary alkyl formates in high yields. The results obtained are discussed in relation to conflicting literature data as regards the synthesis of formates.

https://onlinelibrary.wiley.com/doi/epdf/10.1002/recl.196408...


while formyl chloride is unstable, i've been wondering if you could just generate formyl chloride in situ by dripping thionyl chloride into a mixture of formic acid and alcohol, and the formyl chloride would react instantly before it decomposes.

Another method for formate esters of tertiary alcohols using boron oxide https://www.google.com/url?sa=t&source=web&rct=j&...

[Edited on 21-4-2020 by Cou]

[Edited on 22-4-2020 by Cou]

mackolol - 21-4-2020 at 01:53

Quote: Originally posted by wg48temp9  
You forgot the boric acid method for phenols. Posted here only 9 days ago!


Does this work for synthesising oxalic acid phenyl esters used for chemiluminescence? This would be very useful as it would omit the need for oxalyl chloride. I must try this indeed.

[Edited on 21-4-2020 by mackolol]

wg48temp9 - 21-4-2020 at 09:51

Quote: Originally posted by mackolol  
Quote: Originally posted by wg48temp9  
You forgot the boric acid method for phenols. Posted here only 9 days ago!


Does this work for synthesising oxalic acid phenyl esters used for chemiluminescence? This would be very useful as it would omit the need for oxalyl chloride. I must try this indeed.

[Edited on 21-4-2020 by mackolol]


I don't know if it works oxalic acid but I do know that oxalic acid is decomposed by concentrated sulphuric acid at temperatures above about 100C. Yes it did work in reasonable time below 100C it would be very useful to generate diphenyl oxalate.

kmno4 - 21-4-2020 at 11:02

Quote:

Does this work for synthesising oxalic acid phenyl esters used for chemiluminescence? This would be very useful as it would omit the need for oxalyl chloride. I must try this indeed.

The paper (from TL) is the only one mentioning such reaction.
The authors use mysterionus catalyst, being a mixture of H2SO4 and H2BO3 of unknown composition.
Unfortunalety, heating of phenol and oxalic acid (in toluene etc) give aurin and some soluble solid only. This solid has m.p. very close to DPO, but it is not the ester (it is organic compound of complicated structure).

ps. jak będziesz miał jakieś sukcesy, daj konicznie znać. Tę śmieciową publikację znałem od dawna, ale nie wygląda na to że to działa z kwasem szczawiowym.

mackolol - 22-4-2020 at 03:49

Quote: Originally posted by kmno4  
Quote:

Does this work for synthesising oxalic acid phenyl esters used for chemiluminescence? This would be very useful as it would omit the need for oxalyl chloride. I must try this indeed.

The paper (from TL) is the only one mentioning such reaction.
The authors use mysterionus catalyst, being a mixture of H2SO4 and H2BO3 of unknown composition.
Unfortunalety, heating of phenol and oxalic acid (in toluene etc) give aurin and some soluble solid only. This solid has m.p. very close to DPO, but it is not the ester (it is organic compound of complicated structure).

ps. jak będziesz miał jakieś sukcesy, daj konicznie znać. Tę śmieciową publikację znałem od dawna, ale nie wygląda na to że to działa z kwasem szczawiowym.


I didn't know about the synthesis of aurin, but it seems like this is gonna be main product. Maybe I'll try this in future, maybe substituted phenols such as trichlorophenol behave differently in the synthesis. I'll let you all know when I will perform such synthesis.

p.s. Dzięki za słowa wsparcia, miło usłyszeć ojczysty język na zagranicznym forum :D

wg48temp9 - 22-4-2020 at 06:32

Quote: Originally posted by kmno4  
Quote:

Does this work for synthesising oxalic acid phenyl esters used for chemiluminescence? This would be very useful as it would omit the need for oxalyl chloride. I must try this indeed.

The paper (from TL) is the only one mentioning such reaction.
The authors use mysterionus catalyst, being a mixture of H2SO4 and H2BO3 of unknown composition.
Unfortunalety, heating of phenol and oxalic acid (in toluene etc) give aurin and some soluble solid only. This solid has m.p. very close to DPO, but it is not the ester (it is organic compound of complicated structure).


Perhaps it was wishful thinking the same author has patent on the method.

But I note that the aurin synthesis requires about 140C and 24 hours so perhaps the aurin would only be a minor product below 100C.

PS: I just checked the reaction time in the boric acid paper. Its 8 hours at about 75C the toluene/water azeotropic boiling point. I also noticed the catalyst is "1 - 5mol % boric acid and sulphuric acid" which I interperate as 1-5 mol% of boric acid and 1 -5 mol% of sulphuric acid.

I suspect the aurin synthesis requires the oxalic acid to decompose to react with the phenol.

[Edited on 4/22/2020 by wg48temp9]

mackolol - 22-4-2020 at 11:07

And how much is 1-5mol%? I don't understand such value as mol%...

[Edited on 22-4-2020 by mackolol]

Metacelsus - 22-4-2020 at 11:25

5 mol% would be a ratio of 1 mole acid to 20 moles reactant

mackolol - 22-4-2020 at 11:30

Ok thanks, for sure will be useful, especially in my high school ;)

Cou - 5-6-2020 at 21:56

Which one would you guys recommend for making esters such as tert-butyl acetate?

Acid chlorides are difficult to get b/c of hazmat shipping. Acid chlorides can be made from carboxylic acids, but each method has disadvantages too. Thionyl chloride and phophorus trichloride have hazmat shipping. Triphenylphosphine is expensive.

I'm leaning towards the Steglish esterification. It's still expensive (triphenylphosphine and DCC are similar prices by weight), but none of the chemicals require hazmat shipping, and a step is eliminated (no need to convert carboxylic acid to acid chloride first)

i hope i can make the ester of triphenylmethanol and acetic acid one day.



[Edited on 6-6-2020 by Cou]

Fery - 6-6-2020 at 10:20

Hi Cou, just an idea:
t-butanol + HCl -> t-butyl chloride (this works well, I did it already)
t-butyl chloride + Na acetate -> t-butyl acetate (did not try yet)

karlos³ - 6-6-2020 at 11:53

Quote: Originally posted by Fery  

t-butyl chloride + Na acetate -> t-butyl acetate (did not try yet)

This could work good, I made benzyl acetate this way.
But with tert-butyl halides I think there is an increased risk of elimination instead of substitution.

DraconicAcid - 6-6-2020 at 12:12

Quote: Originally posted by karlos³  
Quote: Originally posted by Fery  

t-butyl chloride + Na acetate -> t-butyl acetate (did not try yet)

This could work good, I made benzyl acetate this way.
But with tert-butyl halides I think there is an increased risk of elimination instead of substitution.


Oooohhh....do you have a write-up for this?

karlos³ - 6-6-2020 at 17:25

No I am sorry I do not.
But it involved refluxing in ethanol for 1-2h or so, and was followed by an extraction after the ester was precipitated with water(into DCM).
Those are the only details I can give you, it is quite a few years ago no and I never regarded that as an important experiment, I was just curious about the smell of benzyl acetate.

I don't think that heating would be a good idea in case of the reaction of tert-butyl halides with a carboxylate salt, due to the elimination.