Sciencemadness Discussion Board

propiophenone from calcium propionate and calcium benzoate

schrodingers_hat - 23-6-2014 at 10:09

Hi all. In the attached excerpt, they discuss a synthesis of propiophenone from benzoic and propionic acid.

If one were to start from the calcium salts of these two compounds, would it be required that they be converted to their acid forms prior to the final reaction?

As the reaction takes place at 250 C, I do not think there is a suitable solvent that could dissolve them in their salt forms and reach said temperature, but reducing propionic acid seems like it would be somewhat difficult. I say this because it is soluble in water and therefore would be dissolved by the the water in the HCL (or other acid) solution.

Would my only option be to add HCL (or other acid) to the calcium propionate then distill off the water, or is there a more elegant solution?

I should add that the article makes no mention to a solvent (because the propionic acid is used as the solvent?)

Attachment: 000512508-davis (2).djvu (92kB)
This file has been downloaded 909 times

[Edited on 23-6-2014 by schrodingers_hat]

leu - 23-6-2014 at 10:30

Using:

http://www.sciencemadness.org/talk/search.php?fid=10

should have found:

http://www.sciencemadness.org/talk/viewthread.php?tid=6347&a...

There's other threads on this subject on this web site and elsewhere that would provide more information :) The end really does result from the effort applied :cool:

solo - 23-6-2014 at 12:54

.....this might be of some help,

http://chemistry.mdma.ch/hiveboard/newbee/000512508.html

...here´s the article quoted,



Decarboxylation Studies. II. Preparation of Alkyl Phenyl Ketones
Charles Granito , Harry P. Schultz
J. Org. Chem.
1963, 28 (3), pp 879–881
DOI: 10.1021/jo01038a521


[Edited on 23-6-2014 by solo]

Attachment: Decarboxylation Studies. II.Preparation of Alkyl Phenyl Ketones.pdf (425kB)
This file has been downloaded 1326 times

Mildronate - 24-6-2014 at 03:58

Anbody have some results with this method? I actually doesnt like steam destilation is it possible to use extraction insead of steam destilation?

leu - 24-6-2014 at 05:52

The reaction mechanism is discussed in:

The Mechanism of the Ketonic Pyrolysis of Calcium Carboxylates C. C. Lee , J. W. T. Spinks J. Org. Chem., 1953, 18 (9), pp 1079–1086 DOI: 10.1021/jo50015a003

which is attached :) Clearly more study is needed very badly since the article has already been downloaded hundreds of times in the previous thread :P The end really does result from the effort applied :cool:

Attachment: jo50015a003.pdf (227kB)
This file has been downloaded 2644 times

[Edited on 24-6-2014 by leu]

schrodingers_hat - 25-6-2014 at 07:05

Thank you Leu. That article cleared everything up. As for the other articles,

Decarboxylation Studies. II.Preparation of Alkyl Phenyl Ketones.pdf

http://www.sciencemadness.org/talk/viewthread.php?tid=6347&a...

are the exact article i attached which makes no reference to solvent used.

That being said, I am still grateful for all of the input. Thank you

Paddywhacker - 25-6-2014 at 20:29

No solvent is used, but maybe the yield would improve if a suitable one was. Maybe a eutectic salt mixture.

Mildronate - 26-6-2014 at 04:03

Maybe its posble to put benzoic acid, Fe powder and propionic acid in steal pipe and heat, actualy why need solvent propionic acid is liquid? I am interested is its posible to extract propiophenone after heatingwith some solvent , because i dont like steam destilation.

ChemPlayer_ - 25-6-2015 at 04:10

I recently tried this using calcium benzoate and calcium propionate. These were both separately prepared then oven dried and mixed in a 2:1 molar ratio of benzoate:propionate, then oven-dried again before being dry distilled in a 500ml flask (110g of mixed salts used).

It took a lot of direct heat on the flask to get the distillate over, but quite a lot was obtained. The resulting liquid was distilled again but even though the high fraction was coming over in a relatively short temperature range, it was seemed a bit impure (bright yellow in colour, too low in bp to be pure propiophenone, and slightly wrong scent).

My conclusion was that if there's a good way to separate a really pure product (precise fractional distillation perhaps) from this then it's a relatively easy and OTC method, but at the cost of risking damaging glassware.

Video of the entire process: https://www.youtube.com/watch?v=WrM7MGMI2uw

hyfalcon - 25-6-2015 at 04:40

Chromatography column. I have no idea which solvent to use for this though. Let some of the other more knowledgeable chime in here.

Pumukli - 30-11-2015 at 09:49

I'm not more knowledgeable but accidentally came across this article. It does use an inert solvent and a Fe-based catalist, treating both as trade secrets though. :-)

LINK

byko3y - 30-11-2015 at 17:01

Pumukli, catalyst is Fe3O4, solvent is Downtherm A.

Pumukli - 4-12-2015 at 10:45

Thanks, byko3y.
May I ask how do you know that? Are you one of the authors? :-)

clearly_not_atara - 4-12-2015 at 16:37

Quote: Originally posted by Pumukli  
Thanks, byko3y.
May I ask how do you know that? Are you one of the authors? :-)

He knows Google-fu.
http://onlinelibrary.wiley.com/doi/10.1002/adsc.201000429/ab...

vannylaholic - 16-10-2017 at 13:50

Would dry distillation calcium glycolate and calcium benzoate yeild mandellic acid?

Chemi Pharma - 17-10-2017 at 07:56

Quote: Originally posted by vannylaholic  
Would dry distillation calcium glycolate and calcium benzoate yeild mandellic acid?


No, you will get major quantities of a keto-alcohol: 1-phenyl, 1-oxo, ethanol-2, and minor quantities of 1,3 dihidroxyacetone, a keto-diol, and diphenyl ketone.

You'd better read again the article Leu had posted above in this thread as an attachment in PDF format: The Mechanism of the Ketonic Pyrolysis of Calcium Carboxylates C. C. Lee , J. W. T. Spinks J. Org. Chem., 1953, 18 (9), pp 1079–1086 DOI: 10.1021/jo50015a003


[Edited on 17-10-2017 by Chemi Pharma]

draculic acid69 - 15-8-2018 at 06:27

I think these rxn's are better run in steel vessels or modified paint/solvent tins.
glass is no good for the temps needed (450'c ish for calcium salts) and the residue can fuse to the glass causing cracking as it cools.look at the NaOH/benzoate to benzene method.maybe the fe salts can be done in glass ( article says 180'c ish) but what kind of residue is left after the distillation.ppl who have successfully done these rxn's w/lead found steel vessels and a slight vacuum increased yields by helping pull the product over From the lava like conditions,I imagine it would help when doing calcium or iron variations as well.no need to use expensive fragile glass for these rxn's.

[Edited on 15-8-2018 by draculic acid69]