Sciencemadness Discussion Board

CuCl2 for friedel crafts

Dr.Q - 20-1-2013 at 03:18

i try to make chlorobenzene from benzene and chlroine but because of hard getting catalysts anhydrous AlCl3 and FeCl3 i cant make it. But CuCl2 is easy to obtain for me i wonder is this reaction possible with a catalyst CuCl2 ?

Boffis - 20-1-2013 at 06:38

I don't know but it might, it wouyld need to be the anhydrous (brown) form not the blue hydrate. Anhydrous ZnCl2 might also work though it is action is less aggressive than AlCl3. Try it and let us know!

Random - 20-1-2013 at 11:38

Quote: Originally posted by Boffis  
I don't know but it might, it wouyld need to be the anhydrous (brown) form not the blue hydrate. Anhydrous ZnCl2 might also work though it is action is less aggressive than AlCl3. Try it and let us know!


Yeah as he said try using anhydrous form though and try first on smaller scale.

But FeCl3 and AlCl3 are both pretty good lewis acids, I don't think thats the case with CuCl2.

ZnCl2 on the other hand if anhydrous may have better chance of success.

[Edited on 20-1-2013 by Random]

SM2 - 20-1-2013 at 12:23

A substitute which would work, AND one which can be made anhydrous through simple heating. That is the key. I'd like to know as well.

smaerd - 20-1-2013 at 13:26

CuCl2 is a weak lewis acid. Try it on activated substrates and see. I've never heard of it. It's preparation isn't too hard but drying it completely seems to be a painful experience iirc.

http://pubs.rsc.org/en/Content/ArticleLanding/2010/CC/C0CC02...
Dramatic micellar rate enhancement of the Cu2+ catalyzed vinologous Friedel–Crafts alkylation in water
Fiora Rosati , Jens Oelerich and Gerard Roelfes
Chem. Commun., 2010,46, 7804-7806
DOI: 10.1039/C0CC02584D

However there are some articles saying bismuth trichloride works on some activated substrates in certain conditions for friedel crafts acylation. It's preparation doesn't look too hard. Although most references I've read citing this claim the trifluorosulfonate Bi salt is more efficient(I probably botched the name of the actual salt my condolences).

http://pubget.com/paper/pgtmp_07f47ec0e89b297bdcc6b8632a4d5c...
BiCl3-catalyzed Friedel-Crafts acylation reactions: bismuth(III) oxychloride as a water insensitive and recyclable procatalyst
Repichet, , Roques, Dubac
Tetrahedron Lett 44(10):0 (2003),

OP please note it is frowned upon to open a thread outside of the Beginnings subforum without references.

edit-
I also recall that FeCl3 anhydrous can be purchased very easily on-line.

[Edited on 20-1-2013 by smaerd]

12AX7 - 20-1-2013 at 13:46

Is it not sufficient to suspend a small amount of Fe2O3 or, better, Fe filings, in the solution? FeCl3 should form in situ when chlorination starts.

Tim

killer_lapin - 20-1-2013 at 15:03

CuCl2 can be use to chlorinate carbonyl at the alpha carbon in presence of aluminium oxide, so maybe it can work on aromatics. And it's is easily dried by putting it in the same container(un sealed) as calcium carbide afters few days you get the brown powder, maybe calcium chloride works too.

Dr.Q - 20-1-2013 at 15:13

Quote: Originally posted by 12AX7  
Is it not sufficient to suspend a small amount of Fe2O3 or, better, Fe filings, in the solution? FeCl3 should form in situ when chlorination starts.

Tim


actually that looks pretty logical !!!

by the way i cant buy chemicals from internet i can only make it by myslef.
i want to try tim's method and CuCl2 but how can i make anhydrous CuCl2 . Will heating up the dihydrate form turn it into anhydrous ???

killer_lapin - 20-1-2013 at 15:19

no it's going to decompose into hydrochloric acid and copper oxide that's why you have to use a dessicating agent. I guess you have access to some chemicals perhaps sodium hydroxide? it might be able to dry the copper chloride.

Also, you can produce your AlCl3 insitu and then add your benzene while keeping the bubbling of chlorine going, but the chlorine has to be dried for both the reaction and AlCl3 production

[Edited on 20-1-2013 by killer_lapin]

[Edited on 20-1-2013 by killer_lapin]

smaerd - 20-1-2013 at 15:45

Sorry I skipped over the whole chlorobenzene part(woooops) of this you can ignore my last post. An alternate reaction scheme would go from aniline and use the old sandmeyer.

[Edited on 20-1-2013 by smaerd]

Vargouille - 20-1-2013 at 17:28

Quote: Originally posted by killer_lapin  
no it's going to decompose into hydrochloric acid and copper oxide that's why you have to use a dessicating agent.


Beg pardon? Not according to Jamit, from his thread on cupric chloride crystals:
Quote:
I've dried the green copper chloride in an oven and obtains the anhydrous brown color.


nor UC235 from his video on the preparation of copper pthalocyanine:
Quote:
I have... 0.67 grams of anhydrous copper (II) chloride, and I prepared this by [preparing a solution of copper (II) chloride] and boiling the solution dry until the solid turned uniformly brown.


[Edited to add links]

[Edited on 21-1-2013 by Vargouille]

Dr.Q - 21-1-2013 at 00:44

Quote: Originally posted by killer_lapin  
no it's going to decompose into hydrochloric acid and copper oxide that's why you have to use a dessicating agent. I guess you have access to some chemicals perhaps sodium hydroxide? it might be able to dry the copper chloride.

Also, you can produce your AlCl3 insitu and then add your benzene while keeping the bubbling of chlorine going, but the chlorine has to be dried for both the reaction and AlCl3 production

[Edited on 20-1-2013 by killer_lapin]

[Edited on 20-1-2013 by killer_lapin]



yes creating the catalyst in situ is a good idea. I will try them.


if i can produce a anhydrous CuCl2 by heating CuCl2.H2O i wil l try it as a catalyst too.

in the links that Vargouille sent , CuCl2.H2O turns anhydrous by heating . But i wonder couldnt it be the Cu2O. Could Cu can reduce by heating ?

[Edited on 21-1-2013 by Myeou]

UnintentionalChaos - 21-1-2013 at 01:00

I should add that anhydrous CuCl2 is extremely hygroscopic. Here is some interesting reading material that is marginally related. http://kraken.chem.wisc.edu/deptfiles/stahl/Stahl%20Publicat...

For making the catalyst in-situ, I'd go with acetone-degreased extra fine steel wool. Lewis acid catalyzed aromatic halogenation is not an FC reaction. The catalyst merely serves to polarize the halogen, providing a more electrophilic target for attack by the nucleophilic aromatic ring.

Vargouille - 21-1-2013 at 06:00

It *could* be Cu2O, in the sense that most anything's possible. It's almost certainly not, however, as Cu2O is red, while anhydrous CuCl2 is brown.

SM2 - 21-1-2013 at 09:54

Quote: Originally posted by killer_lapin  
CuCl2 can be use to chlorinate carbonyl at the alpha carbon in presence of aluminium oxide, so maybe it can work on aromatics. And it's is easily dried by putting it in the same container(un sealed) as calcium carbide afters few days you get the brown powder, maybe calcium chloride works too.


So do you think the aluminum oxide acted as a sort of promoter here? It's interesting. I've spend a couple of weeks in a medical library down in the journal archive dungeon, and I bet there was a thousand page volume dedicated exclusively to fridel-crafts promoted alkylations. We all know many of the grignard tricks, but when it comes to fridel-crafts, it's not so common.

Dr.Q - 21-1-2013 at 10:38

so i reacted FeCl3 and NaOH to get Fe(OH)3 . After that i filter th epercipate and heat it at 150 - 200 degree. In the end i belive that it was Fe2O3 not all of it but some of it .
Than i take the percipate and pour it into pure benzene. Than i bubbled the benzene with chlorine. Benzene is color turn t o yellow as i expected. The problem is there was no change in Fe2O3 when bubbling.Now i am waiting . But the yellow color of benzene isnt changing still. That means there is no reaction happening.
So i think Fe2O3 in benzene doenst reacted with Cl2 to form FeCl3.
What am i doing wrong ? Is it about Fe2O3 ?

Nicodem - 21-1-2013 at 11:07

I don't understand what are you trying to achieve with Fe2O3? How could it ever act as a catalyst? What is the original reference for that?
Also, why would you want to use something as impractical as chlorine gas instead of a proper lab-scale chlorination reagent? Why don't you simply use the procedure already published on this forum? Not to mention the multitude of literature examples that you could have used.

Dr.Q - 21-1-2013 at 11:14

Quote: Originally posted by Nicodem  
I don't understand what are you trying to achieve with Fe2O3? How could it ever act as a catalyst? What is the original reference for that?
Also, why would you want to use something as impractical as chlorine gas instead of a proper lab-scale chlorination reagent? Why don't you simply use the procedure already published on this forum? Not to mention the multitude of literature examples that you could have used.


i dont use Fe2O3 as a catalyst. Cl2 will react with Fe2O3 in benzene to from FeCl3 that matter will act as a catalyst.
Things that i can get is very limited thats why i cant use the published procedures.

[Edited on 21-1-2013 by Myeou]

Nicodem - 21-1-2013 at 11:31

Quote: Originally posted by Myeou  
i dont use Fe2O3 as a catalyst. Cl2 will react with Fe2O3 in benzene to from FeCl3 that matter will act as a catalyst.

That does not make any sense to me. How could such a reaction proceed and what is the reference?
Quote:
Things that i can get is very limited thats why i cant use the published procedures.

You can obtain benzene and chlorine gas, but you can't obtain chemicals that are sold in any larger store?

12AX7 - 21-1-2013 at 16:26

I hypothesized about that earlier, but I don't know if it will chlorinate. Evidently not! Fe(OH)3 might, but the H2O byproduct won't help very much. Better use metal then.

Tim