| Pages:
1
..
15
16
17
18
19
..
26 |
questions
Hazard to Others
Posts: 103
Registered: 12-2-2011
Location: Australia
Member Is Offline
Mood: curious
|
|
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?
|
|
|
Melgar
Anti-Spam Agent
Posts: 2004
Registered: 23-2-2010
Location: Connecticut
Member Is Offline
Mood: Estrified
|
|
| 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.
|
|
|
questions
Hazard to Others
Posts: 103
Registered: 12-2-2011
Location: Australia
Member Is Offline
Mood: curious
|
|
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?
|
|
|
mnick12
Hazard to Others
Posts: 404
Registered: 30-12-2009
Location: In the lab w/ Dr. Evil
Member Is Offline
Mood: devious
|
|
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!
|
|
|
Sedit
International Hazard
Posts: 1939
Registered: 23-11-2008
Member Is Offline
Mood: Manic Expressive
|
|
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
|
|
|
madcedar
Hazard to Others
Posts: 116
Registered: 10-9-2009
Member Is Offline
Mood: No Mood
|
|
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
|
|
|
madcedar
Hazard to Others
Posts: 116
Registered: 10-9-2009
Member Is Offline
Mood: No Mood
|
|
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  attachment.
Attachment: pat6380448 Method for recovering styrene monomer from polystyrene resin by using a catalyst.pdf (938kB)
This file has been downloaded 1168 times
|
|
|
Melgar
Anti-Spam Agent
Posts: 2004
Registered: 23-2-2010
Location: Connecticut
Member Is Offline
Mood: Estrified
|
|
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 3147 times
|
|
|
madcedar
Hazard to Others
Posts: 116
Registered: 10-9-2009
Member Is Offline
Mood: No Mood
|
|
Thanks for that Melgar.
|
|
|
Melgar
Anti-Spam Agent
Posts: 2004
Registered: 23-2-2010
Location: Connecticut
Member Is Offline
Mood: Estrified
|
|
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.
|
|
|
roamingnome
Hazard to Others
Posts: 363
Registered: 9-9-2006
Member Is Offline
Mood: No Mood
|
|
Thanks Melgar
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
|
|
|
Melgar
Anti-Spam Agent
Posts: 2004
Registered: 23-2-2010
Location: Connecticut
Member Is Offline
Mood: Estrified
|
|
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
|
|
|
Sedit
International Hazard
Posts: 1939
Registered: 23-11-2008
Member Is Offline
Mood: Manic Expressive
|
|
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
|
|
|
Melgar
Anti-Spam Agent
Posts: 2004
Registered: 23-2-2010
Location: Connecticut
Member Is Offline
Mood: Estrified
|
|
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.
|
|
|
BlueChemist
Harmless
Posts: 2
Registered: 22-2-2011
Member Is Offline
Mood: No Mood
|
|
Benzaldehyde is used as an industrial/commercial non-oxidising biocide.
|
|
|
roamingnome
Hazard to Others
Posts: 363
Registered: 9-9-2006
Member Is Offline
Mood: No Mood
|
|
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
|
|
|
questions
Hazard to Others
Posts: 103
Registered: 12-2-2011
Location: Australia
Member Is Offline
Mood: curious
|
|
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?
|
|
|
Nicodem
|
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
|
|
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.
|
|
|
questions
Hazard to Others
Posts: 103
Registered: 12-2-2011
Location: Australia
Member Is Offline
Mood: curious
|
|
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?
|
|
|
questions
Hazard to Others
Posts: 103
Registered: 12-2-2011
Location: Australia
Member Is Offline
Mood: curious
|
|
Is there anyone reading this thread?
I've made a couple of posts now and no one has responded.........
|
|
|
Sedit
International Hazard
Posts: 1939
Registered: 23-11-2008
Member Is Offline
Mood: Manic Expressive
|
|
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
|
|
|
questions
Hazard to Others
Posts: 103
Registered: 12-2-2011
Location: Australia
Member Is Offline
Mood: curious
|
|
Any reply is a good one, so thanks Sedit
|
|
|
questions
Hazard to Others
Posts: 103
Registered: 12-2-2011
Location: Australia
Member Is Offline
Mood: curious
|
|
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?
|
|
|
Sedit
International Hazard
Posts: 1939
Registered: 23-11-2008
Member Is Offline
Mood: Manic Expressive
|
|
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 1267 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
|
|
|
madcedar
Hazard to Others
Posts: 116
Registered: 10-9-2009
Member Is Offline
Mood: No Mood
|
|
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?
|
|
|
|
| Pages:
1
..
15
16
17
18
19
..
26 |
![[*]](images/xpblue/default_icon.gif){kind=icon}
