FloridaAlchemist
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Research Project Idea Paradichlorobenzene
This is a research project idea for the home experimenter: Para Dichlorobenze mothball substitute can probably be used in a home lab for making other
reagents if you 1st try to substitute one of the chlorines with Iodine...Very old and mostly overlooked method. then you can remove the iodine and get
chlorobenzene.
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Haggis
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One could then use bromine to knock out the chlorine in chloro-benzene and aquire bromo-benzene. This chemical shall have lacrymating properties like
bromo-acetone. On the subject of mothballs, anyone have any ideas on how to cleave the benzene rings apart in the old napthalene mothballs?
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Nick F
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Oxidation of napthalene (acidified permangante under reflux, I *think*) will yield phthalic acid, decarboxylation of this by distilling it from CaO
should yield benzene via benzoic acid.
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Organikum
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When trying to distill benzene out from the benzoic acid/CaO one should add some CuSO4 and also then this is no fun at all.
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stygian
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| Quote: | Originally posted by FloridaAlchemist
This is a research project idea for the home experimenter: Para Dichlorobenze mothball substitute can probably be used in a home lab for making other
reagents if you 1st try to substitute one of the chlorines with Iodine...Very old and mostly overlooked method. then you can remove the iodine and get
chlorobenzene. |
How might one go about doing this? How do you substitute I for a Cl and then remove? methinks chlorobenzene would be nice to have 
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guy
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| Quote: | Originally posted by stygian
| Quote: | Originally posted by FloridaAlchemist
This is a research project idea for the home experimenter: Para Dichlorobenze mothball substitute can probably be used in a home lab for making other
reagents if you 1st try to substitute one of the chlorines with Iodine...Very old and mostly overlooked method. then you can remove the iodine and get
chlorobenzene. |
How might one go about doing this? How do you substitute I for a Cl and then remove? methinks chlorobenzene would be nice to have |
yeah I want to know too
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12AX7
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I take it the Cls stick pretty damn well? I mean, what's base do, fusing anhydrous if necessary? P-hydroxyphenol ought to have *some* acidity to
allow this to go forward...
Tim
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not_important
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The chlorines stick really well. Refluxing with AlCl3 results mostly in the formation of ortho and meta isomers, with little transfers to give mono
and tri chlorobenzenes (you can for it with a good column and very slow distillation) That is a decent way to get a mix of o- and m- dichlorobenzene,
which is a useful solvent for some reactions, just chill the reaction mix to crystallize out most of the remaining para-DCB and recycle it.
I think that the alkali fusion route doesn't work well, lot of byproducts. Aqueous base under high pressure does go, similar to the commericial
production of phenol from chlorobenzene.
Mononitration, which takes a bit of effort, followed by boiling alkali with the slow addition of H2O2 replaces the Cl ortho to the NO2 with OH. The
H2O2 isn't functioning in a redox fashion, it's base form interacts with the NO2- and Cl-
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Sauron
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ortho-chlorophenyl derivatives ten to be very very nasty.
1,2-dichlorobenzene
2,-chlorophenol
2-chloronitrobenzene
All very unpleasant and toxic so be warned.
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guy
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Is the subsitution with hydroxide slow but favorable?
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FloridaAlchemist
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1st Add a Nitro Group
Fist put a nitro group on the ring to give 2-nitro para dichlorobenzene. It should now be possible to work on the chlorines
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S.C. Wack
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US3064059 claims that pDCB is hydrodechlorinated to chlorobenzene by their process in some yield that they refuse to give. Probably other exotic
but different patents could be found.
There is something here and there on catalytic transfer of 1 chlorine from pDCB to benzene, and some reductions which maybe could be stopped at the
chlorobenzene stage. But most reductions (Al/Ni/NaOH, Zn/Ni/NaOH, Ni/H, supported Pt or especially Pd, electroreduction with Pb cathode in divided
cell with MeOH, hydrides, PPh3, etc.) that I've seen mentioned seem to go all the way to benzene. Don't have access to any of those articles and
abstracts are abstracts so who knows.
[Edited on 20-1-2007 by S.C. Wack]
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