Author Topic: Alternative Way To Make Benzaldehyde  (Read 5484 times)

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Bwiti

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Alternative Way To Make Benzaldehyde
« on: October 20, 2001, 11:44:00 PM »

  Here's the abstract from GB165747's 'Improved manufacture of acid anhydrides':

"Organic acid anhydrides are prepared by heating an aromatic compound containing more than one halogen atom in the side chain, e.g. benzal chloride or benzotrichloride, with the anhydrous alkali or alkaline-earth salt of a carboxylic acid. The reaction may take place under increased or reduced pressure; an indifferent solvent, such as xylene, may be added; mixtures of salts instead of the individual salts may be employed; and free acid, such as acetic acid, or previously-prepared acid anhydride, may be present. In the examples, acetic anhydride is obtained from benzotrichloride and anhydrous sodium or calcium acetate, and from benzal chloride or p-chlorbenzotrichloride and dry sodium acetate; propionic anhydride is prepared from benzotrichloride and dry sodium propionate; and benzoic anhydride is made from benzotrichloride and dry sodium benzoate. When the starting material is a compound having a dihalogenated side-chain, the corresponding aldehyde is formed as a by-product; thus, benzaldehyde is produced along with acetic anhydride when benzal chloride is heated with dry sodium acetate."

  


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halfapint

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Re: Alternative Way To Make Benzaldehyde
« Reply #1 on: October 21, 2001, 11:24:00 AM »
That's a nifty one. It's tittilating enough to make me spill the beans on the benzaldehyde prep I was going to spring as a surprise, a gem I dug out of my old chem texts. The proper way to introduce this would of course bee in a synth report, but my lab agenda is way beehind at the moment, so here it is:

You can make benzaldehyde by heating calcium benzoate with calcium formate. The first source I read on this implied you had to use the double salt, calcium benzoate formate, or in other words the organic acids both had to be salted on the same calcium atom, but later readings indicate you can use an intimate equimolar mix of the individual salts, calcium benzoate and calcium formate. Naturally, I was going to bring this out in the context of the elusive fabled benzoic acid to meth synth, and if people harass me too much for specific citations and documentation, guess I'll still have to run it myself, and give myself as the authority.

Meditation: Whether you can make, say, 3,4,5-trimethoxy benzaldehyde from 3,4,5-trimethoxy benzoic acid calcium or barium salt, and calcium or barium formate, I haven't the froggiest idea. Haven't even done the first one yet, simple benzoic acid. Or whether any of the various tars I've produced in my speckled career could have been rescued by an acid permanganate oxidation to the aryl acid, salted with lime and then dry distilled with calcium formate for the aldehyde, only the chem gods know.

turning science fact into <<science fiction>>

goiterjoe

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Re: Alternative Way To Make Benzaldehyde
« Reply #2 on: October 21, 2001, 12:52:00 PM »
distillation from the bitter almond oil sold at health food stores sounds like an easier alternative, unless this is not available where you live.

Sed quis custodiet ipsos custodes?

halfapint

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Re: Alternative Way To Make Benzaldehyde
« Reply #3 on: October 21, 2001, 01:12:00 PM »
OK for a little bitty bit. (Or if you can find artificial almond flavoring through grocers, it's got alcohol added to the benzaldehyde.) You can get a little bit of sassy oil at retail too. In bulk, though, bitter almond oil has become one of those touchy things, for this very reason. Some distribs have dropped it, at others you can expect curiosity over sales to individuals who are new customers... The kind of curiosity to avoid.

turning science fact into <<science fiction>>

Bwiti

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Re: Alternative Way To Make Benzaldehyde
« Reply #4 on: October 23, 2001, 04:50:00 PM »
Fuckin' A! That would make a good addition to Rhodium's page!

"Whether you can make, say, 3,4,5-trimethoxy benzaldehyde from 3,4,5-trimethoxy benzoic acid calcium or barium salt, and calcium or barium formate, I haven't the froggiest idea."

  I'm wondering the same about GB165747. Instead of using benzal chloride, the chloride of benzodioxole? Some day, someone with the cash to blow will try it and we'll find out. Lately, I'm interested in finding patents that use plain old benzaldehyde as a stepping stone to piperonal and other benz. that turn-out methylenedioxyamphetamines. 8)

  I'm going to help all of you cleanse this diseased planet.

Rhodium

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Re: Alternative Way To Make Benzaldehyde
« Reply #5 on: October 23, 2001, 05:02:00 PM »
Test it and make a writeup for me, and I'll add it to my page.

Acme

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Re: Alternative Way To Make Benzaldehyde
« Reply #6 on: October 24, 2001, 05:21:00 AM »
Maybee you could use the Blanc Reaction to make your Benzodioxazole benzyl Chloride.

            Blanc Reaction

Benzene + CH2O + HCl -->> Benzyl Chloride
                    ZnCl2

Org React 1, 63 (1942)

and the product could be treated with cyanide, then condensed with EtOAc and decarboxylated as per the Russians.

foxy2

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Re: Alternative Way To Make Benzaldehyde
« Reply #7 on: October 24, 2001, 05:40:00 AM »

Maybee you could use the Blanc Reaction to make your Benzodioxazole benzyl Chloride.

               Blanc Reaction

   Benzene + CH2O + HCl -->> Benzyl Chloride
                       ZnCl2

   Org React 1, 63 (1942)

   and the product could be treated with cyanide, then condensed with EtOAc and decarboxylated as per the Russians.





Would you bee so kind as to transcribe these procedures or post links ect?


Do Your Part To Win The War

Bwiti

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Methylenedioxybenzene - US3436403
« Reply #8 on: October 24, 2001, 08:52:00 AM »
I have one question regarding this synthesis: I fucking hate steam distillation. Can I avoid this by adding a shit-load of H2O to the reaction mixture, then extract the product with ether? Any info on tweaking this procedure would be much appreciated!



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Acme

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Re: Alternative Way To Make Benzaldehyde
« Reply #9 on: October 24, 2001, 09:23:00 AM »
Referring to:

Would you bee so kind as to transcribe these procedures or post links ect?



--------------------------------------------------------------------------------
Do Your Part To Win The War 

No, I will not; I don't have time for that shit;  go to the library (Do Your Part To Win The War) and/or UTFSE 



Strike Total Synthesis p120 mentions this procedure but is a little vague so pick up CA, 33, 377 (1939) too


and foxy2, for proc f, for 91% yield they are getting for 6oomL of distillate for 1oo g product, how much tweaking to you gonna do?

Lino

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Re: Alternative Way To Make Benzaldehyde
« Reply #10 on: October 29, 2001, 02:31:00 AM »
Bwiti, steam dist.'s cool… well… 'bout 100ºC ish! :) . AFAIK… don't think one can stick the MD bridge on benzaldahyde. Is that what you meant? Naaaaaaaaaaaa.

NOW. As we're on the subject I'll give you lazy wannnnnnaBeees another chance! In a recent post (Obit) (?) I discovered Benzal (see the A not Y) chloride AKA summat else ;)  could be easily transmogrified (new synth) to… BENZALDAHYDE CAS 100-52-7, FW 106.12, C7H6O mp-26, bp178-185 …

The summat else has also a 3,4-summat else variation. PLEASE: after consideration, could any knowledgeable Bee constructively comment.  :)

Linoleum: the 13th element!  Now available at all good DIY stores… & Walmart.

Aurelius

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Re: Alternative Way To Make Benzaldehyde
« Reply #11 on: October 29, 2001, 07:15:00 AM »
yeah, you take the dichloromethylbenzene (benzal) and add some good ol' hydroxide and heat a little bit and the OH takes the place for each of the halogens, that makes a geminal diol which automatically dehydrates to give the aldehyde.  (and who is Obit? heard she's dead :P )

Lino

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Re: Alternative Way To Make Benzaldehyde
« Reply #12 on: November 01, 2001, 03:37:00 AM »
Aurelius, thank you kindly sir/madam. I'm sorry to hear of the demise of the good Bee Obit ;)
Is dichloromethylbenzene same as a,a-Dichlorotoluene? What dilution NaOH would be suitable, 25%, 10% or would one add the solid? I suppose same process applies to 3,4-Dichlorotoluene to give… a vanillin fragrance product?  :)

Linoleum: the 13th element!  Now available at all good DIY stores… & Walmart.

Rhodium

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Re: Alternative Way To Make Benzaldehyde
« Reply #13 on: November 01, 2001, 03:41:00 AM »
Yes, dichloromethylbenzene is the same as a,a-Dichlorotoluene? You can probably use either 10% or 20%, but 20-25% would probably be the best.

Antoncho

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Re: Alternative Way To Make Benzaldehyde
« Reply #14 on: November 01, 2001, 07:14:00 AM »
To all whom it may concern - check out the piperonal via chloromethylation of benzodioxole thread in the Novel Discourse, it kicks ass.

This catechol methylenation proc. Bwiti posted is a very nice conponent to that synth - thanks a lot, Bwiti!

Antoncho

Aurelius

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Re: Alternative Way To Make Benzaldehyde
« Reply #15 on: November 02, 2001, 01:20:00 AM »
yes, the two chloro compounds are one-in-the-same

and Rhodium is right, use about 20% it's just easy and clean that way.  the reaction should give you high yeild. (aurelius thinks that it's around 90%+ )

Lino

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Re: Alternative Way To Make Benzaldehyde
« Reply #16 on: November 02, 2001, 04:58:00 AM »
Aurelius & Rhodium, thanks v.much. An early xmas present, in 2 ziplocks, has been stuffed down left hand side of The Couch. Near that horrid white stain that Os' left when he and Stoni… ;)

Linoleum: the 13th element!  Now available at all good DIY stores… & Walmart.

Aurelius

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Re: Alternative Way To Make Benzaldehyde
« Reply #17 on: November 02, 2001, 05:27:00 AM »
just make sure you seal the bags VERY tightly... and perhaps dye the product for verification