Author Topic: phenylacetic acid -Scooby Doo  (Read 1344 times)

0 Members and 1 Guest are viewing this topic.

dormouse

  • Guest
phenylacetic acid -Scooby Doo
« on: April 19, 2000, 09:21:00 AM »

   the Hive BB
  Novel Discourse
  phenylacetic acid
  
profile | register | preferences | faq | search
 
 next newest topic | next oldest topic 
Author  Topic:   phenylacetic acid 
Scooby Doo
Member   posted 04-21-98 03:19 AM          
--------------------------------------------------------------------------------
Had a dream a while ago where a friend was reading in Fieser & Fieser (reagents for organic synthesis) that phenylacetic acid could be obtained by oxidizing ethylbenzene with sodium dichromate (23% excess) in water at 250C for 18 hours. However these claims by Reitsma and Allphin had not been confirmed at the time the book was published. My friend was wondering if anyone had similar or later dreams to this one?
 
RatHead
unregistered   posted 04-28-98 05:07 AM           
--------------------------------------------------------------------------------
Yes ethyl benzene will oxidize to Phenylacetic acid.
An alternative to the long time required for dichromate is to use KMnO4 buffered with magnesium sulfate in water. Use the two phase method I described with ether/water.
 
RatHead
unregistered   posted 04-28-98 05:07 AM           
--------------------------------------------------------------------------------
Yes ethyl benzene will oxidize to Phenylacetic acid.
An alternative to the long time required for dichromate is to use KMnO4 buffered with magnesium sulfate in water. Use the two phase method I described with ether/water.
 
Scooby Doo
Member   posted 04-28-98 11:49 AM          
--------------------------------------------------------------------------------
Thank you for your reply. I knew of KMnO4 being used, but could not find any material on it. I thought it might have been too strong.
 
Scooby Doo
Member   posted 04-28-98 11:49 AM          
--------------------------------------------------------------------------------
Thank you for your reply. I knew of KMnO4 being used, but could not find any material on it. I thought it might have been too strong.
 
spiceboy
Member   posted 04-28-98 11:56 AM          
--------------------------------------------------------------------------------
Hey whats up?....Yes KMnO4 is damn strong. In acid media, its at its strongest, where in neutral its a little weaker, and in basic, weaker still, which is probably in the range of the chrome salts...I think....
 
spiceboy
Member   posted 04-28-98 11:56 AM          
--------------------------------------------------------------------------------
Hey whats up?....Yes KMnO4 is damn strong. In acid media, its at its strongest, where in neutral its a little weaker, and in basic, weaker still, which is probably in the range of the chrome salts...I think....
 
RatHead
unregistered   posted 04-28-98 03:36 PM           
--------------------------------------------------------------------------------
Yes don't use it in a hot conc. acidic rxn. But in diluted cold form or buffered it can selectively oxidize one carbon at a time.
 
RatHead
unregistered   posted 04-28-98 03:36 PM           
--------------------------------------------------------------------------------
Yes don't use it in a hot conc. acidic rxn. But in diluted cold form or buffered it can selectively oxidize one carbon at a time.
 
Scooby Doo
Member   posted 04-30-98 11:19 AM          
--------------------------------------------------------------------------------
Found a different approach to producing ethyl benzene by the reduction of actophenone. Now I am not sure how restricted actophenone since it is a procuser for P2P via diazomethane. However the reduction is carried out using a Nickel-aluminum alloy (1:1). Which is treated with sodium hydroxide to form a black sponge which is an effective hydrogenation catalyst that can be used to produce ethylbenzene from acetophenone in a 70% yield. Just wondering if any bees had herd anything about this?
 
Scooby Doo
Member   posted 04-30-98 11:19 AM          
--------------------------------------------------------------------------------
Found a different approach to producing ethyl benzene by the reduction of actophenone. Now I am not sure how restricted actophenone since it is a procuser for P2P via diazomethane. However the reduction is carried out using a Nickel-aluminum alloy (1:1). Which is treated with sodium hydroxide to form a black sponge which is an effective hydrogenation catalyst that can be used to produce ethylbenzene from acetophenone in a 70% yield. Just wondering if any bees had herd anything about this?
 
Rhodium
Administrator   posted 04-30-98 02:33 PM          
--------------------------------------------------------------------------------
It would probably be a lot cheaper to reduce acetophenone to ethylbenzene via the clemmensen reduction (Zinc amalgam in HCl) - yields should be okay. And don't worry about acetophenone being suspicious, it is made very easily via friedel crafts acylation of benzene (i hope acetyl chloride isn't as watched as the anhydride in the US, or is it?).
And we have also the Wolff-Kischner reaction for doing the reduction, but that would certainly not be cost effective 


Rhodium
Administrator   posted 04-30-98 02:33 PM          
--------------------------------------------------------------------------------
It would probably be a lot cheaper to reduce acetophenone to ethylbenzene via the clemmensen reduction (Zinc amalgam in HCl) - yields should be okay. And don't worry about acetophenone being suspicious, it is made very easily via friedel crafts acylation of benzene (i hope acetyl chloride isn't as watched as the anhydride in the US, or is it?).
And we have also the Wolff-Kischner reaction for doing the reduction, but that would certainly not be cost effective 


Scooby Doo
Member   posted 04-30-98 09:39 PM          
--------------------------------------------------------------------------------
Thank you for your reply. This will keep me busy in the old chemistry libary for a while. I'm not sure of the status of acetyl chloride or acetic anhydride for that matter. However I trying to obtain a chem catalouge which might be able to shed some light on this topic, but info will probably only be useful to Aussie viewers.
I have been looking for Rathead's two phase method but so far have been unsuccessful. Is it in the old data base or hidden somewhere in the new? (Its probably right in front of me),would apreciate a bee's assistance.
 
Scooby Doo
Member   posted 04-30-98 09:39 PM          
--------------------------------------------------------------------------------
Thank you for your reply. This will keep me busy in the old chemistry libary for a while. I'm not sure of the status of acetyl chloride or acetic anhydride for that matter. However I trying to obtain a chem catalouge which might be able to shed some light on this topic, but info will probably only be useful to Aussie viewers.
I have been looking for Rathead's two phase method but so far have been unsuccessful. Is it in the old data base or hidden somewhere in the new? (Its probably right in front of me),would apreciate a bee's assistance.
 
Optimus Prime
Member   posted 05-01-98 03:50 PM          
--------------------------------------------------------------------------------
If someone had some phenylacetic acid how much would an oz. of it cost???roughly...I know you can't get it any more but if someone had some to sell what would be a fair price???
OP


Optimus Prime
Member   posted 05-01-98 03:50 PM          
--------------------------------------------------------------------------------
If someone had some phenylacetic acid how much would an oz. of it cost???roughly...I know you can't get it any more but if someone had some to sell what would be a fair price???
OP


Osmium
Member   posted 05-04-98 04:52 AM          
--------------------------------------------------------------------------------
Acetophenone can be transformed to PAA with the Willgerodt-Kindler reaction using sulfur and a high-boiling secondary amine. Don't convert it to ethylbenzene!
And I have to repeat that PAA can be made from plain old STYRENE via that W.-K.-reaction in about 80%.


Osmium
Member   posted 05-04-98 04:52 AM          
--------------------------------------------------------------------------------
Acetophenone can be transformed to PAA with the Willgerodt-Kindler reaction using sulfur and a high-boiling secondary amine. Don't convert it to ethylbenzene!
And I have to repeat that PAA can be made from plain old STYRENE via that W.-K.-reaction in about 80%.


Osmium
Member   posted 05-04-98 04:56 AM          
--------------------------------------------------------------------------------
There are some benzyl chloride recipies here, which sound as if they can be done big-scale. React it with NaCN and hydrolyse the benzyl cyanide. See Org. Synth. for complete instructions.
 
Osmium
Member   posted 05-04-98 04:56 AM          
--------------------------------------------------------------------------------
There are some benzyl chloride recipies here, which sound as if they can be done big-scale. React it with NaCN and hydrolyse the benzyl cyanide. See Org. Synth. for complete instructions.
 
BOZAKIUM
unregistered   posted 05-04-98 10:53 PM           
--------------------------------------------------------------------------------
Yeah benzene souds easy enough to start with, but is really hard to come by in the US due to it's carcinogenicity. Any one know a way to start from toulene?
BTW, just for a cock-teaser, in the upcoming Fester opus is a slick & simple electrolytic way to make phenylacetone from the acid. I don't think I should worry that the Fascist narcoswine are reading this, as they already know we know how to make phenylacetone, and have already crimped upon the acid. Even if they list everything with a benzene ring, there's always the Diels-Alder reaction. hehe
 
BOZAKIUM
unregistered   posted 05-04-98 10:53 PM           
--------------------------------------------------------------------------------
Yeah benzene souds easy enough to start with, but is really hard to come by in the US due to it's carcinogenicity. Any one know a way to start from toulene?
BTW, just for a cock-teaser, in the upcoming Fester opus is a slick & simple electrolytic way to make phenylacetone from the acid. I don't think I should worry that the Fascist narcoswine are reading this, as they already know we know how to make phenylacetone, and have already crimped upon the acid. Even if they list everything with a benzene ring, there's always the Diels-Alder reaction. hehe
 
Osmium
Member   posted 05-05-98 03:22 AM          
--------------------------------------------------------------------------------
1. Bozakium: Diels-Alder doesn't produce benzenes. What do you have in mind?
2. Benzylchloride is made from toluene.
3. Refs for Willgerodt with styrene:
JACS 64 (1942), 3051
JACS 68 (1946), 2335-7


Osmium
Member   posted 05-05-98 03:22 AM          
--------------------------------------------------------------------------------
1. Bozakium: Diels-Alder doesn't produce benzenes. What do you have in mind?
2. Benzylchloride is made from toluene.
3. Refs for Willgerodt with styrene:
JACS 64 (1942), 3051
JACS 68 (1946), 2335-7


RatHead
unregistered   posted 05-05-98 08:26 AM           
--------------------------------------------------------------------------------
Just another variationon PAA the acid reacts with lithium grignards to give the ketones in good yields. The Li compoinds can be prepared from LiCl and methyl magnesium iodide.
 
RatHead
unregistered   posted 05-05-98 08:26 AM           
--------------------------------------------------------------------------------
Just another variationon PAA the acid reacts with lithium grignards to give the ketones in good yields. The Li compoinds can be prepared from LiCl and methyl magnesium iodide.
 
drone 342
Member   posted 05-05-98 10:25 AM          
--------------------------------------------------------------------------------
bozakium, I posted all the info on that electrolytic ketone formation stuff about a week or two ago. Look amongst the many threads dealing with benzyl chloride and phenylacetic acid, and you'll find it all there in spades. In fact, I give ref's on going from benzyl choride to p-2-p -- can't get much stylier than that!
With all this talk about styrenes, has anybody given thought to depolymerization of styrofoam coolers to yield the monomer in question? I'm sure people have, but has anyone ref's therefrom?

-drone #342


drone 342
Member   posted 05-05-98 10:25 AM          
--------------------------------------------------------------------------------
bozakium, I posted all the info on that electrolytic ketone formation stuff about a week or two ago. Look amongst the many threads dealing with benzyl chloride and phenylacetic acid, and you'll find it all there in spades. In fact, I give ref's on going from benzyl choride to p-2-p -- can't get much stylier than that!
With all this talk about styrenes, has anybody given thought to depolymerization of styrofoam coolers to yield the monomer in question? I'm sure people have, but has anyone ref's therefrom?

-drone #342


Scooby Doo
Member   posted 05-05-98 11:14 AM          
--------------------------------------------------------------------------------
Thanks for the very tasty input guys! OP sorry to take a while on your question, about $70-80 US for a kilo. However certian derivatives cost a shit load more, Phenylacetic carboxy13C acid 1g = $281 Aust.
 
Scooby Doo
Member   posted 05-05-98 11:14 AM          
--------------------------------------------------------------------------------
Thanks for the very tasty input guys! OP sorry to take a while on your question, about $70-80 US for a kilo. However certian derivatives cost a shit load more, Phenylacetic carboxy13C acid 1g = $281 Aust.
 
Osmium
Member   posted 05-06-98 04:36 AM          
--------------------------------------------------------------------------------
Thermal depolymerization of styrene doesn't work, because you will get only a small percentage of styrene and lots of other shit.
But styrene is no problem to get, ask chem supplier (expensive), or buy from plastic resin supplier in gallon quantities (used in polyester resins).
 
Osmium
Member   posted 05-06-98 04:36 AM          
--------------------------------------------------------------------------------
Thermal depolymerization of styrene doesn't work, because you will get only a small percentage of styrene and lots of other shit.
But styrene is no problem to get, ask chem supplier (expensive), or buy from plastic resin supplier in gallon quantities (used in polyester resins).