Sciencemadness Discussion Board

Preparation of HCB from benzene via electrophilic substitution

AirCowPeaCock - 31-8-2012 at 09:47

Could I chlorinate benzene all the way to Hexachlorobenzene using Iron Chloride as the catalyst? I am concerned the ajacent Chlorines will protect the last Chlorines from attaching (specifically from pentachlorobenzene and 1,2,3,5 tetrachlorobenzene). However, won't the carbon become more electrophilic as the more electronegitive Chlorines pull e- from the ring? Would these two opposing forces balence eachother out?

Hexavalent - 31-8-2012 at 11:16

Assuming you live in the States, are you sure it's legal to make it in the US?

http://www.epa.gov/osw/hazard/wastemin/minimize/factshts/hex...

Also, are you certain about the catalyst?

This page; http://www.chemguide.co.uk/mechanisms/elsub/halogenation.htm... suggests elemental iron or aluminium chloride to be used for the halogenation of benzene, although with the Al/Fe salt issue it may not make a difference.

[Edited on 31-8-2012 by Hexavalent]

AirCowPeaCock - 31-8-2012 at 14:09

" This page; http://www.chemguide.co.uk/mechanisms/elsub/halogenation.htm... suggests elemental iron or aluminium chloride to be used for the halogenation of benzene, although with the Al/Fe salt issue it may not make a difference.". I dont understand what your trying to say here. I was going to use elemental iron and form it in the reaction (-80 mesh granular steel actually.)

I knew HCB was banned for agriculture, I didn't know it was illegal to produce. Although this may not apply to a small lab prep. HCB might not be the ideal compound though. Im trying to make green flash powder without chlorate or Mg, but normal pyrotechnic chlorine sources decomp to slowly (or rather not readily enough) for this. HCB was used in pyrotechnics as a chlorine donoe for awhile so that was one of my first ideas. Perhaps a less substituted chlorobenzene would be preferable as it may be more prone to oxidation(?)

plante1999 - 31-8-2012 at 14:17

Hexachloro ethane might be what you are looking for, I could possibly sell some of my supply.

AirCowPeaCock - 31-8-2012 at 14:27

I was thinking of Hexachloroethane aswell. U2U me?

[Edited on 8-31-2012 by AirCowPeaCock]