Process for the manufacture ethylbenzene?

maybe

Quote: Originally posted by Chemosynthesis

Friedel Crafts

My first thought was FC alkylation of benzene with ethyl bromide, but the ethylbenzene would be more reactive than the original benzene, and would react further leading to over alkylation.

What about FC acylation of benzene with acetyl chloride, which would then be followed up with a reduction of the carbonyl with zinc(hg) and HCl?

[Edited on 11-6-2015 by Loptr]

EDIT: No answer needed. I found this exact reaction online and confirmed it. Clemmensen reduction

[Edited on 11-6-2015 by Loptr]

EDIT: Or you could just start with my product, acetophenone, and follow with a Clemmensen reduction.

[Edited on 11-6-2015 by Loptr]

Quote: Originally posted by Praxichys

Start from styrene, since it is easy to manufacture from common plastic items. Hydrogenate gently. http://www.researchgate.net/profile/Antoine_Fecant/publicati...

Quote: Originally posted by Tom Yorke

my way seems easiest but whatever

Is this a competition? I must have missed that. What are the prizes?

EDIT: I just checked your reaction and you would end up with styrene! And then you go on to say you don't know what would need to be done with the double bond, so you left off where Praxichys began... yeah, your way seems easier when you don't have to deal with the double bond.


[Edited on 11-6-2015 by Loptr]

Quote: Originally posted by Loptr

Quote: Originally posted by Chemosynthesis   Friedel Crafts My first thought was FC alkylation of benzene with ethyl bromide, but the ethylbenzene would be more reactive than the original benzene, and would react further leading to over alkylation. What about FC acylation of benzene with acetyl chloride, which would then be followed up with a reduction of the carbonyl with zinc(hg) and HCl? [Edited on 11-6-2015 by Loptr] EDIT: No answer needed. I found this exact reaction online and confirmed it. Clemmensen reduction [Edited on 11-6-2015 by Loptr] EDIT: Or you could just start with my product, acetophenone, and follow with a Clemmensen reduction. [Edited on 11-6-2015 by Loptr]

EDIT: I just checked your reaction and you would end up with styrene! And then you go on to say you don't know what would need to be done with the double bond, so you left off where Praxichys began... yeah, your way seems easier when you don't have to deal with the double bond.

sweet, thanks for checking that out, I had a bad feeling about that thing. now I know why that's not used to get ethylbenenzene, bio-styrene is pretty awesome though.

Quote: Originally posted by Praxichys

True, but the hydrogenation will have a small ethylcyclohexane, ethylcyclohexene, ethylcyclohexadiene impurity which will be very close in BP and difficult to separate. The acylation/reduction is cleaner but requires a lot more expense in reagents. It depends on the purity required for the final application.

among all the methods mentioned till now,the hydrogenation of styrene seems to be the best approach.I found another paper on that
http://jes.ecsdl.org/content/143/4/L71.abstract

magpie's method is nothing but the wurtz-fittig reaction.In that case,benzyl bromide and methyl iodide could also be coupled using Na.But I have a better idea,phenylmagnesium bromide +ethyl bromide(kumada coupling)
http://www.organic-chemistry.org/namedreactions/kumada-coupl...

but the best thing to do would be to just buy it.its dirt cheap(the irony is that styrene is made by dehydrogenation of ethylbenzene )

Quote: Originally posted by UC235

Quote: Originally posted by Praxichys   True, but the hydrogenation will have a small ethylcyclohexane, ethylcyclohexene, ethylcyclohexadiene impurity which will be very close in BP and difficult to separate. The acylation/reduction is cleaner but requires a lot more expense in reagents. It depends on the purity required for the final application. No you wouldn't. Pd/C is not capable of reducing an aromatic ring easily as far as I know, but an aryl conjugated terminal alkene should be an extremely easy target.

I found an example on Google Books that shows Pd/C doesn't reduce the aromatic ring, while a rhodium-alumina catalyst does. The example is the reduction of mandelic acid.

https://books.google.com/books?id=7gPnWf4UDLsC&lpg=PA416...

Personally, I would stick with the acylation. This is possibly because I remember doing it very clearly in college, while the hydrogenation also seems to have a costly barrier to entry.

[Edited on 12-6-2015 by Loptr]

[Edited on 12-6-2015 by Loptr]

Quote: Originally posted by Loptr

the hydrogenation also seems to have a costly barrier to entry

Quote: Originally posted by S.C. Wack

Quote: Originally posted by Loptr   the hydrogenation also seems to have a costly barrier to entry Ni (without heat) and Cu (reduced from their oxides) are supposed to give quantitative yield at 85 atm. in 3 hr., but then if one would go for that, why not 94% from polystyrene and U-Ni-B at 350C at the same pressure in less time, ftw, profit, etc.

I was speaking from the perspective of an equipment poor home chemist.

While it might be less costly for industry to run these sorts of reactions, I am not quite sure how you would go about it exactly in your garage without metal working abilities. That's just me, though, not to mention that I also have no interest in this product...