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General Forums => Generic Discussion => Topic started by: HalfLife on April 29, 2014, 02:13:43 PM

Title: Benzaldehyde from phenylalanine
Post by: HalfLife on April 29, 2014, 02:13:43 PM
hi,
is there any paper about the reaction of phenylalanine with sodium hydroxyde to give benzaldehyde ? i can't seem to find any, i have heard it was possible here
http://www.chemicalforums.com/index.php?PHPSESSID=57c4e6bd68cf4b63286d0b4d1256ce91&topic=3905.msg17380#msg17380
Title: Re: Benzaldehyde from phenylalanine
Post by: Archer on April 30, 2014, 05:34:55 AM
hi,
is there any paper about the reaction of phenylalanine with sodium hydroxyde to give benzaldehyde ? i can't seem to find any, i have heard it was possible here
http://www.chemicalforums.com/index.php?PHPSESSID=57c4e6bd68cf4b63286d0b4d1256ce91&topic=3905.msg17380#msg17380


This is unlikely to give very good recovery of benzaldehyde as the product undergoes a Cannizzaro reaction in the presence of hydroxide producing benzylalcohol and benzoic acid in equal proportions
Title: Re: Benzaldehyde from phenylalanine
Post by: HalfLife on April 30, 2014, 03:54:24 PM
hi,
is there any paper about the reaction of phenylalanine with sodium hydroxyde to give benzaldehyde ? i can't seem to find any, i have heard it was possible here
http://www.chemicalforums.com/index.php?PHPSESSID=57c4e6bd68cf4b63286d0b4d1256ce91&topic=3905.msg17380#msg17380


This is unlikely to give very good recovery of benzaldehyde as the product undergoes a Cannizzaro reaction in the presence of hydroxide producing benzylalcohol and benzoic acid in equal proportions
thank you your help Archer!
do you have more informations about this reaction like papers or threads as i'm really interrested, even if it produce benzylalcohol and benzoic acid these can be converted to benzaldehyde
Title: Re: Benzaldehyde from phenylalanine
Post by: Archer on April 30, 2014, 08:23:27 PM
Benzaldehyde is pretty cheap, this method would be very costly.

Can't you just buy it? Or buy the corresponding acid or alcohol?

Benzoic acid is as cheap as chips.
Title: Re: Benzaldehyde from phenylalanine
Post by: HalfLife on May 01, 2014, 04:23:44 AM
Benzaldehyde is pretty cheap, this method would be very costly.

Can't you just buy it? Or buy the corresponding acid or alcohol?

Benzoic acid is as cheap as chips.

 im trying to make it myself this is why i'm asking
Title: Re: Benzaldehyde from phenylalanine
Post by: Archer on May 01, 2014, 05:29:27 AM

 im trying to make it myself this is why i'm asking


I understand but you are going to start with phenylalanine, attempt to covert via benzaldehyde to a crude mixture of benzoic acid and benzylalcohol, then slectively oxidise the alcohol to the aldehyde or selectively reduce the acid to the aldehyde.

First of all I am not convinced that this reaction would work in the first place. I can't see a rational mechanism for this to happen.

So why not skip the dubious step one and purchase some benzoic acid and make benzaldehyde from that?

There are many routes to making benzaldehyde, why not investigate an alternative precursor?
Title: Re: Benzaldehyde from phenylalanine
Post by: HalfLife on May 01, 2014, 08:16:14 AM

 im trying to make it myself this is why i'm asking


I understand but you are going to start with phenylalanine, attempt to covert via benzaldehyde to a crude mixture of benzoic acid and benzylalcohol, then slectively oxidise the alcohol to the aldehyde or selectively reduce the acid to the aldehyde.

First of all I am not convinced that this reaction would work in the first place. I can't see a rational mechanism for this to happen.

So why not skip the dubious step one and purchase some benzoic acid and make benzaldehyde from that?

There are many routes to making benzaldehyde, why not investigate an alternative precursor?

what other alternatives ? i don't have toluene, essential oils are too expensive and benzyl alcohol is hard to get for me whereas
phenylalanine sodium hydroxide and calcium hypochlorite are readly available
and this reaction even if it involve alot of work i still find it very attractive

again thanks for your help Archer
Title: Re: Benzaldehyde from phenylalanine
Post by: HalfLife on May 01, 2014, 08:20:57 AM
the only mention i found about this process is here
http://web.archive.org/web/20070404062521/http://www.ajinomoto.co.jp/amino/e_aminoscience/bc/amino_13.html

maybe someone have a more detailed paper or thread?
Title: Re: Benzaldehyde from phenylalanine
Post by: Archer on May 01, 2014, 10:21:23 AM
the only mention i found about this process is here
http://web.archive.org/web/20070404062521/http://www.ajinomoto.co.jp/amino/e_aminoscience/bc/amino_13.html

maybe someone have a more detailed paper or thread?

I would imagine that

Quote
Unstable in alkali. When heated in 5N sodium hydroxide at 110~115° for 5 hours, it decomposes forming benzaldehyde

Means that if you heat it up for long enough it smells like benzaldehyde.

I have some experience of similar compounds and yes you often see benzaldehyde come up in the strangest of places but it is never a complete or quantitative conversion.

If you have plently of the ingredients then give it a go. I can't find any mention of this reaction occuring in any ot the sources I have checked.
Title: Re: Benzaldehyde from phenylalanine
Post by: HalfLife on May 01, 2014, 02:28:43 PM
the only mention i found about this process is here
http://web.archive.org/web/20070404062521/http://www.ajinomoto.co.jp/amino/e_aminoscience/bc/amino_13.html

maybe someone have a more detailed paper or thread?

I would imagine that

Quote
Unstable in alkali. When heated in 5N sodium hydroxide at 110~115° for 5 hours, it decomposes forming benzaldehyde

Means that if you heat it up for long enough it smells like benzaldehyde.

I have some experience of similar compounds and yes you often see benzaldehyde come up in the strangest of places but it is never a complete or quantitative conversion.

If you have plently of the ingredients then give it a go. I can't find any mention of this reaction occuring in any ot the sources I have checked.

i find it strange that there is no literature about it, i will try it anyway and see what happen
Archer do you have some literature about the reaction of benzyl alcohol with hypochlorite salts to give benzaldehyde?

thx
Title: Re: Benzaldehyde from phenylalanine
Post by: Archer on May 01, 2014, 02:41:47 PM
the only mention i found about this process is here
http://web.archive.org/web/20070404062521/http://www.ajinomoto.co.jp/amino/e_aminoscience/bc/amino_13.html

maybe someone have a more detailed paper or thread?

I would imagine that

Quote
Unstable in alkali. When heated in 5N sodium hydroxide at 110~115° for 5 hours, it decomposes forming benzaldehyde

Means that if you heat it up for long enough it smells like benzaldehyde.

I have some experience of similar compounds and yes you often see benzaldehyde come up in the strangest of places but it is never a complete or quantitative conversion.

If you have plently of the ingredients then give it a go. I can't find any mention of this reaction occuring in any ot the sources I have checked.

i find it strange that there is no literature about it, i will try it anyway and see what happen
Archer do you have some literature about the reaction of benzyl alcohol with hypochlorite salts to give benzaldehyde?

thx


I am afraid not, i am very set in my ways and still use the Corey an Suggs method with pyridinium chlorochromate.

It's old but extremely reliable and work up (discounting cleaning the sinter) is a sinch.

Why the interest in benzaldehyde anyway? What's your application of the product?
Title: Re: Benzaldehyde from phenylalanine
Post by: 408 on May 01, 2014, 10:55:23 PM
What about aspartame?  if you are trying to do this from common household stuff...
http://pubs.acs.org/doi/abs/10.1021/jf960079k?journalCode=jafcau

Paper text here:
https://www.sciencemadness.org/whisper/viewthread.php?tid=19083

And they are studying benzaldehyde production in foodstuffs, so you know most things included are common.


I found a reaction of phenylalanine with TCCA giving phenylacetonitrile

Found a reaction of phenylalanine with bacteria giving benzaldehyde
http://aem.asm.org/content/64/8/3009.abstract?sid=2011f452-1bcf-480b-b377-e6e761ca9971


Searching for all links to the japanese reference site was funny ;)  ....but the end result is that this reaction is referenced lots, but never done successfully, and everyone who has tried says it does not work. 

Conclusion:  find another route.




Title: Re: Benzaldehyde from phenylalanine
Post by: HalfLife on May 02, 2014, 07:40:25 AM
What about aspartame?  if you are trying to do this from common household stuff...
http://pubs.acs.org/doi/abs/10.1021/jf960079k?journalCode=jafcau

Paper text here:
https://www.sciencemadness.org/whisper/viewthread.php?tid=19083

And they are studying benzaldehyde production in foodstuffs, so you know most things included are common.


I found a reaction of phenylalanine with TCCA giving phenylacetonitrile

Found a reaction of phenylalanine with bacteria giving benzaldehyde
http://aem.asm.org/content/64/8/3009.abstract?sid=2011f452-1bcf-480b-b377-e6e761ca9971


Searching for all links to the japanese reference site was funny ;)  ....but the end result is that this reaction is referenced lots, but never done successfully, and everyone who has tried says it does not work. 

Conclusion:  find another route.

thank you for all these references
as for benzaldehyde from phenylalanine the reaction was  never done successfully probably because the benzaldehyde goes through Cannizzaro reaction so only benzyl alchol and benzoic acid is generated, this is what i think i might be wrong
but if this work then you could make benzaldehyde from benzyl alcohol, i will try it and see what happen