Sciencemadness Discussion Board
Not logged in [Login ]
Go To Bottom

Printable Version  
 Pages:  1  ..  15    17    19  ..  25
Author: Subject: toluene --> benzaldehyde
questions
Hazard to Others
***




Posts: 103
Registered: 12-2-2011
Location: Australia
Member Is Offline

Mood: curious

[*] posted on 12-2-2011 at 23:31
Benzaldehyde


Quote: Originally posted by Melgar  
Benzaldehyde can be made pretty easily by mixing styrene, acetone, and a small amount of water (like 5% of the quantity of acetone) then running ozone into the mixture, which should ideally be kept as cold as possible to prevent the evaporation of acetone. This method of ozonolysis seems to only produce good yields with terminal alkenes such as styrene though.


Hey, I liked your method of making benzaldehyde from styrene, acetone water and ozone.

Have you actually tried this method?
And if you have tried this method, did it work well?
View user's profile View All Posts By User
Melgar
Anti-Spam Agent
*****




Posts: 2004
Registered: 23-2-2010
Location: Connecticut
Member Is Offline

Mood: Estrified

[*] posted on 15-2-2011 at 17:18


Quote: Originally posted by questions  
Quote: Originally posted by Melgar  
Benzaldehyde can be made pretty easily by mixing styrene, acetone, and a small amount of water (like 5% of the quantity of acetone) then running ozone into the mixture, which should ideally be kept as cold as possible to prevent the evaporation of acetone. This method of ozonolysis seems to only produce good yields with terminal alkenes such as styrene though.


Hey, I liked your method of making benzaldehyde from styrene, acetone water and ozone.

Have you actually tried this method?
And if you have tried this method, did it work well?

I have, and it works pretty well. You make a solution of 95% acetone and 5% water, then mix in the styrene (I used about a quarter styrene) and run ozone through it. The two main problems with this method are 1) the acetone tends to evaporate, so you need to constantly refill it, and 2) you need however many moles of ozone as you have styrene, and since an ozone generator typically outputs 2-3 percent ozone, this can take a while. You can minimize lost acetone by keeping the reaction really cold, but unless it's winter, that can be hard to do. So really, this reaction works best in the winter. :)

Also, the first time you do this reaction, do it with maybe 10 mL of styrene, just so you get an idea of how long it takes to ozonolyze it. I started with like 250 mL and it took way too long and I was never able to finish.

The article that describes this method is here:
http://pubs.acs.org/doi/abs/10.1021/jo800323x

I have the full text pdf if you can't get it yourself.

The nice thing about this is purification is easy, if you're not a stickler for purity. Just heat it to like 150C in a narrow-neck boiling flask and leave it there for a while and the styrene and acetone and water will boil away leaving mostly benzaldehyde.
View user's profile View All Posts By User
questions
Hazard to Others
***




Posts: 103
Registered: 12-2-2011
Location: Australia
Member Is Offline

Mood: curious

[*] posted on 15-2-2011 at 19:30
benzaldehyde from ozone


I read on the wikipedia that ozone can be produced in the laboratory as shown on the link below.

Laboratory productionIn the laboratory, ozone can be produced by electrolysis using a 9 volt battery, a pencil graphite rod cathode, a platinum wire anode and a 3 molar sulfuric acid electrolyte.[45] The half cell reactions taking place are:

3 H2O → O3 + 6 H+ + 6 e− (ΔEo = −1.53 V)
6 H+ + 6 e− → 3 H2 (ΔEo = 0 V)
2 H2O → O2 + 4 H+ + 4 e− (ΔEo = −1.23 V)
In the net reaction, three equivalents of water are converted into one equivalent of ozone and three equivalents of hydrogen. Oxygen formation is a competing reaction.

It can also be prepared by applying 10,000-20,000 volts DC to dry O2. This can be done with an apparatus consisting of two concentric glass tubes sealed together at the top, with in and out spigots at the top and bottom of the outer tube. The inner core should have a length of metal foil inserted into it connected to one side of the power source. The other side of the power source should be connected to another piece of foil wrapped around the outer tube. Dry O2 should be run through the tube in one spigot. As the O2 is run through one spigot into the apparatus and 10,000-20,000 volts DC are applied to the foil leads, electricity will discharge between the dry dioxygen in the middle and form O3 and O2 out the other spigot. The reaction can be summarized as follows:[6]

3 O2 — electricity → 2 O3

Do you think that this is something I could set up in my garage?

If so do you think that the yeilds of ozone will be good enough for our pures of making benzaldehyde via your styrene method?
View user's profile View All Posts By User
mnick12
National Hazard
****




Posts: 404
Registered: 30-12-2009
Location: In the lab w/ Dr. Evil
Member Is Offline

Mood: devious

[*] posted on 15-2-2011 at 19:42


HV does indeed produce ozone, have you ever messed around with a moniter flyback transformer?

Two things worth mentioning, one ozone is pretty toxic and you really dont want " concentrated" ozone. And secondly I am pretty sure the intermediate in this reaction is an ozonide which can be very unstable past certain tempuratures, so make sure you keep it cool!
View user's profile View All Posts By User
Sedit
International Hazard
*****




Posts: 1939
Registered: 23-11-2008
Member Is Offline

Mood: Manic Expressive

[*] posted on 15-2-2011 at 19:44


You could use a Neon sign transformer or an oil burner transformer. The later has a built in rectifing circuit which is nice. These output anywhere from 10k-20k at around 24-45MA. The voltage can be kicked up rather easy by filling wine bottles with salt water and a layer of oil on top. Place a coat hanger down thru the cork and use this as one terminal of a capacitor. Place the salt water filled bottle into a small cooler also filled with salt water and oil. A wire placed into this solution will act as the other size of the capacitor. The only theoretical limit to the voltage is the amount of bottles you have each acting as a capacitor in its own right. Take care with this capacitor because even though it appears simple it can kill you if your not careful. I was hit by it one time and needless to say I didn't play with it for a few months after that slowly building up my nerve to get near it again.




Knowledge is useless to useless people...

"I see a lot of patterns in our behavior as a nation that parallel a lot of other historical processes. The fall of Rome, the fall of Germany — the fall of the ruling country, the people who think they can do whatever they want without anybody else's consent. I've seen this story before."~Maynard James Keenan
View user's profile View All Posts By User
madcedar
Hazard to Others
***




Posts: 116
Registered: 10-9-2009
Member Is Offline

Mood: No Mood

[*] posted on 16-2-2011 at 00:22


Hello Melgar

Can you please post the pdf of the "Ozonolysis in Solvent/Water Mixtures: Direct Conversion of Alkenes to Aldehydes and Ketones" in this thread for those of us without access.

Kind Regards
Rod

Quote: Originally posted by Melgar  

I have the full text pdf if you can't get it yourself.
View user's profile View All Posts By User
madcedar
Hazard to Others
***




Posts: 116
Registered: 10-9-2009
Member Is Offline

Mood: No Mood

[*] posted on 16-2-2011 at 06:00
thermolysis of polystyrene to styrene


Styrene can be obtained from polystyrene at temperatures approaching 500 degrees and preferably under vacuum.

http://www.ncbi.nlm.nih.gov/pubmed/18032014

Also at lower temperatures by using a sulphate catalyst if you are a person who believes patents. Please refer to the short 30 page :o attachment.

Attachment: pat6380448 Method for recovering styrene monomer from polystyrene resin by using a catalyst.pdf (938kB)
This file has been downloaded 967 times
View user's profile View All Posts By User
Melgar
Anti-Spam Agent
*****




Posts: 2004
Registered: 23-2-2010
Location: Connecticut
Member Is Offline

Mood: Estrified

[*] posted on 17-2-2011 at 06:49


Here it is. Not sure if this is supposed to be posted in the references forum, but it makes more sense to post it here.

Attachment: ozonolysis.pdf (108kB)
This file has been downloaded 2863 times

View user's profile View All Posts By User
madcedar
Hazard to Others
***




Posts: 116
Registered: 10-9-2009
Member Is Offline

Mood: No Mood

[*] posted on 17-2-2011 at 07:38


Thanks for that Melgar.
View user's profile View All Posts By User
Melgar
Anti-Spam Agent
*****




Posts: 2004
Registered: 23-2-2010
Location: Connecticut
Member Is Offline

Mood: Estrified

[*] posted on 17-2-2011 at 09:38


FYI, I have done this reaction and verified it works, however it would be impossible for me to quantify yields due to my lack of making any precise measurements. It did, however, produce several milliliters of benzaldehyde using a very puny ozone generator, so it's definitely an option.

Everything I've read points toward neon sign transformers as the best electronic source for making ozone generators. If you don't have an old neon sign, they only cost like $30 on ebay, plus the one I got has built-in circuitry to prevent you from frying it in the inevitable case where you short-circuit the thing. It definitely generates lots of ozone when electrify foil on two sides of a piece of glass, but I haven't gotten around to building something that can generate ozone and then pump it through a tube into solution though.
View user's profile View All Posts By User
roamingnome
National Hazard
****




Posts: 363
Registered: 9-9-2006
Member Is Offline

Mood: No Mood

[*] posted on 17-2-2011 at 17:53


Thanks Melgar :o

This looks like a real nugget, a game changer even.

No Lindlar's catalyst nor hydrogen

It deserves its own thread though :( because toluene is not an alkene

I see some nice write-ups already
View user's profile View All Posts By User
Melgar
Anti-Spam Agent
*****




Posts: 2004
Registered: 23-2-2010
Location: Connecticut
Member Is Offline

Mood: Estrified

[*] posted on 17-2-2011 at 19:34


Ozonolysis is a really cool type of reaction. They used to use it to figure out the structure of organic molecules because the reaction with C=C bonds is so reliable. Basically, you convert C=C to C=O O=C, ie, break the double bond and put an oxygen on either side. With this method, you're generating two aldehydes, but the other is formaldehyde which evaporates at a really low temperature.

Usually though, it has to be done at a really low temperature and can generate explosive peroxides, but this method gets around that.

But anyway, gotta go, gf is naked and tempting me. :-D
View user's profile View All Posts By User
Sedit
International Hazard
*****




Posts: 1939
Registered: 23-11-2008
Member Is Offline

Mood: Manic Expressive

[*] posted on 17-2-2011 at 19:47


Na stay where your at, ill go handle that for you. You look like you could use some time to yourself so relax ill be there in a minute.




Knowledge is useless to useless people...

"I see a lot of patterns in our behavior as a nation that parallel a lot of other historical processes. The fall of Rome, the fall of Germany — the fall of the ruling country, the people who think they can do whatever they want without anybody else's consent. I've seen this story before."~Maynard James Keenan
View user's profile View All Posts By User
Melgar
Anti-Spam Agent
*****




Posts: 2004
Registered: 23-2-2010
Location: Connecticut
Member Is Offline

Mood: Estrified

[*] posted on 18-2-2011 at 11:23


I posted an ozone generator design in the technochemistry forum. It's set up for nice high air flow rates, which should maximize ozone production.
View user's profile View All Posts By User
BlueChemist
Harmless
*




Posts: 2
Registered: 22-2-2011
Member Is Offline

Mood: No Mood

[*] posted on 22-2-2011 at 16:54


Benzaldehyde is used as an industrial/commercial non-oxidising biocide.
View user's profile View All Posts By User
roamingnome
National Hazard
****




Posts: 363
Registered: 9-9-2006
Member Is Offline

Mood: No Mood

[*] posted on 9-3-2011 at 19:13


Thank you blue chemist , it is also used for almond cakes


http://www.videojug.com/webvideo/how-to-dissolve-styrofoam-a...

the sound track is motivational and i love intelligent Asian boys (wait that came out wrong)

anyway my question is about the nature of the styrene in that form. I guess i sorta already know the answer. Some type of unpolymerized amorous blob. but wilst in solution its treatment affected by ozone attack may produce useful syntheons.


References:
Polymer Degradation and Stability
Volume 79, Issue 2, 2003, Pages 297-307
Influence of ozone on styrene–ethylene–butylene–styrene (SEBS) copolymer

bingo...
Oxidative Degradation of Polymers in Presence of Ozone
The main products appear to be aldehydes and ketones in the case of polyethylene, while an ozonide or peroxidic complex, stable at intermediate temperatures, forms during polystyrene ozonization. The activation energy is of the order of 9 kcal. for polyethylene; for polystyrene it is considerably less.
OZONE CHEMISTRY AND TECHNOLOGY
Chapter 26, pp 168–175
Chapter DOI: 10.1021/ba-1959-0021.ch026
Advances in Chemistry, Vol. 21
ISBN13: 9780841200227eISBN: 9780841221680


View user's profile View All Posts By User
questions
Hazard to Others
***




Posts: 103
Registered: 12-2-2011
Location: Australia
Member Is Offline

Mood: curious

smile.gif posted on 17-3-2011 at 19:18
benzaldehyde from toluene and nickle oxide


Has anyone actual tried making benzaldehyde acording to the method Eng. Pat. 22887, 1900 ?

The link is here;

http://v3.espacenet.com/publicationDetails/originalDocument?...

In this method they react 300 parts of toluene with 150 parts of nickle oxide and heat it for 5 to 6 hours and then filter of the nickle compound formed and then use steam to get the benzaldehyde out of the unreacted toluene.

Has anyone actualy tried this method and if so, how much benzaldehyde was actualy made and how much of each reactant was used?
View user's profile View All Posts By User
Nicodem
Super Moderator
Thread Split
22-4-2011 at 08:14
questions
Hazard to Others
***




Posts: 103
Registered: 12-2-2011
Location: Australia
Member Is Offline

Mood: curious

[*] posted on 16-5-2011 at 20:28
benzaldehyde from nickel oxide


I know a guy who said he tried making benzaldehyde acording to the method Eng. Pat. 22887, 1900 and he told me that it doesn't work :(

So that is the end of the nickel oxide and toluene idea.
View user's profile View All Posts By User
questions
Hazard to Others
***




Posts: 103
Registered: 12-2-2011
Location: Australia
Member Is Offline

Mood: curious

[*] posted on 16-5-2011 at 20:38
Benzaldehyde from US3531519


What about making benzaldehyde according to US3531519 whereby H2O2, sulfuric acid and copper sulfate is used.

In the literature it states that for a 100ml solution of sulfuric acid, hydrogen peroxide and coppersulfate which is mixed with 100ml of toluene and heated to 90C and stirred, the yeilds of benzaldehyde is 48% :)

This certainly seems promising and easy enough to do, also I like the fact that it states the yeilds, so this means that obviously they have tested it to be able to claim a yeild.

The question is, how long does it take for the toluene to get converted to benzaldehyde?
View user's profile View All Posts By User
questions
Hazard to Others
***




Posts: 103
Registered: 12-2-2011
Location: Australia
Member Is Offline

Mood: curious

[*] posted on 19-5-2011 at 20:43


Is there anyone reading this thread?
I've made a couple of posts now and no one has responded.........
View user's profile View All Posts By User
Sedit
International Hazard
*****




Posts: 1939
Registered: 23-11-2008
Member Is Offline

Mood: Manic Expressive

[*] posted on 19-5-2011 at 20:50


Didn't me and you have this discussion before in another thread?

We are not here for your own personal mental masturbators.... if the patent is that simple stop waiting for us to try it for you and go friggin do it already. If you have not attempted this while waiting for us to respond then you obviously can't perform this process. IE: your becomming a burden on the community by never giving back so please shape up, share on or ship out will ya.





Knowledge is useless to useless people...

"I see a lot of patterns in our behavior as a nation that parallel a lot of other historical processes. The fall of Rome, the fall of Germany — the fall of the ruling country, the people who think they can do whatever they want without anybody else's consent. I've seen this story before."~Maynard James Keenan
View user's profile View All Posts By User
questions
Hazard to Others
***




Posts: 103
Registered: 12-2-2011
Location: Australia
Member Is Offline

Mood: curious

[*] posted on 20-5-2011 at 02:49


Any reply is a good one, so thanks Sedit
View user's profile View All Posts By User
questions
Hazard to Others
***




Posts: 103
Registered: 12-2-2011
Location: Australia
Member Is Offline

Mood: curious

[*] posted on 20-5-2011 at 03:01


I've been reading a lot of your disscussions with other people on this site Sedit, and you always seem to be prick. What is with you?
View user's profile View All Posts By User
Sedit
International Hazard
*****




Posts: 1939
Registered: 23-11-2008
Member Is Offline

Mood: Manic Expressive

[*] posted on 20-5-2011 at 05:53


Its a natural gift I have, it pushes people to experiment instead of just talking about experimenting. It also hopefully will push someone to look more into it because they would see that not only was that patent discussed in this thread but also in one called Toluene oxidation fun started by Polverone.

Read closely in the patent because Copper sulfate and sulfuric acid is not the best candidate here, indeed the best results where yeilded from Iron Sulfate and Nitric acid at 85 degrees C topping off at 74.5% after three hours of reaction time.

Do you realize how much could have been accomplished while you waited for us to reply on if it worked on not?

Attachment: US3531519.pdf (194kB)
This file has been downloaded 1040 times





Knowledge is useless to useless people...

"I see a lot of patterns in our behavior as a nation that parallel a lot of other historical processes. The fall of Rome, the fall of Germany — the fall of the ruling country, the people who think they can do whatever they want without anybody else's consent. I've seen this story before."~Maynard James Keenan
View user's profile View All Posts By User
madcedar
Hazard to Others
***




Posts: 116
Registered: 10-9-2009
Member Is Offline

Mood: No Mood

[*] posted on 20-5-2011 at 18:09


Exactly.

Quote: Originally posted by Sedit  
... Do you realize how much could have been accomplished while you waited for us to reply on if it worked on not?

View user's profile View All Posts By User
 Pages:  1  ..  15    17    19  ..  25

  Go To Top