Dan the Chemist
Member
Joined: 20 May 2006
Posts: 18
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 Posted: Sat May 20, 2006 4:47 pm Post subject: |
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Ok, ferric bromide is your lewis acid, which co-ordinates to the Br2, polarising the Br-Br bond, which is basically a source of 'Br+'.
1. Relative to the reaction with benzene, this reaction will be slower (inductive withdrawal of electron density from the ring by chlorine =>the ring's nucleophilicity is decreased)
2. Expect ortho and para substitution - if you draw the carbocation intermediate of ortho and para substitution, you will see that it has 4 resonance structures (remember pi donation by Cl), but the intermediate in meta substitution only has 3 resonance structures (cannot be stabilised by pi donation from Cl)
Look up 'substituent effects' in any general organic textbook.
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