Hello everyone,
I've been searching for direct method for making divanilyl oxalate from oxalic acid and vanillin.
I only have found synthesis routes via oxalyl chloride intermediate.
Well, honestly, I don't reall want to work with oxalyl chloride so I hope there is possibility to find way to skip it and do this synthesis in other
way.
I wonder if anyone here can give me lil' clue where to search?UC235 - 20-6-2016 at 11:03
Possibly you could use dimethyl oxalate and transesterify with distillation (co-distillation with a higher boiling solvent probably) of the methanol
being the driving force to form the energetically unfavorable diphenolic ester. Dimethyl oxalate is pretty prone to hydrolysis as well and anhydrous
oxalic acid is needed for its preparation: http://www.orgsyn.org/Content/pdfs/procedures/CV2P0414.pdf
As for the divanillyl oxalate, I assume you are interested in it because of the attached paper? I have spoken in private with Nurdrage about this
compound. He has made it and finds it considerably inferior to bis(2,4,6-trichlorophenyl)oxalate for chemiluminescence.
[Edited on 20-6-2016 by UC235]Neme - 20-6-2016 at 11:19
Thank you for the attachment, I will look into it deeper as soon as I get time.
And reason why I'm interested in this substance is my high school project focused on chemiluminiscence. I'm trying to find easiest and safest way to
synthesise it.
Btw: I really did not expect answer from you, since your videos on luminol synthesis were my first source of informations for this project. It's pitty
you are not posting videos anymore Metacelsus - 20-6-2016 at 15:52
You could also try using a Dean-Stark trap with refluxing toluene, to remove water and drive the reaction to completion.
Also: Vanillin is an aldehyde. Wouldn't it need to be oxidized to the acid before esterification?
Edit: Derp. (see below)
[Edited on 6-21-2016 by Metacelsus]Crowfjord - 20-6-2016 at 16:49
It's a phenolic ester of oxalic acid. The phenol group of vanillin is the part participating in the reaction.
This sounds pretty cool. I might give the modified synthesis a shot at some point. Finally something to do with the dimethyl oxalate I made two years
ago!
[Edited on 21-6-2016 by Crowfjord]clearly_not_atara - 21-6-2016 at 21:37
Wouldn't you get 3,4-dimethoxybenzaldehyde?
You might however be able to do the esterification with oxamide/ZnO, which is a system used for some similar reactions. Examples include MeOH/urea/ZnO
>> dimethyl carbonate and HOEtOH/urea/ZnO >> ethylene carbonate.
You could also transesterify vanillyl acetate made from vanillin and Ac2O distilling off AcOH. I think this might be your best bet, since acetic acid
is pretty volatile and phenyl esters are pretty reactive. Ac2O is most easily made:
* by distillation from anhydrous zinc acetate, Zn2(OAc)4 >> Zn2(OAc)2O + Ac2O, which is wasteful but super easy from GAA
* by distillation from silver acetate, 2AgOAc >> Ag2O + Ac2O, which is potentially awesome but I've never seen literature confirmation (???) yet
seems to be a widely-believed reaction
* by reaction of acetate or possibly diacetate (the latter being easier to dry) salts with nonmetal halides or nitrogen tetroxide, NaOAc +
[POCl3/COCl2/SOCl2/S2Cl2/S2Br2/NO2], with the nitrogen tetroxide route demonstrated in a video by chemplayer.
* by reaction of mercuric acetate with alkynes (famously methylacetylene) to enol acetates, followed by distillation with additional acetic acid
* by pyrolysis of acetone to the insidious deadly gas ketene/ethenone, for which there is no antidote; it destroys the part of your lungs that absorbs
oxygen and you suffocate while still breathing, anyway, ethenone reacts with water, acetic acid or sodium acetate to acetic anhydride.
[Edited on 22-6-2016 by clearly_not_atara]Crowfjord - 22-6-2016 at 07:32
Maybe, although from this thread and the paper in the first post, alkylation with dialkyl oxalates is performed with a base. Although, phenols aren't very
nucleophilic when protonated...
