Revising Advanced Organic Chemistry Doc Brown's GCE Chemistry
Revision Notes PART 10 Summary of organic reaction mechanisms - A mechanistic introduction to organic chemistry and explanations of different types of organic reactions
Part 10.8 Aromatic Hydrocarbons - Arenes - Electrophilic substitution reactions - SULFONATION
Part 10.8 AROMATIC HYDROCARBONS (ARENES) - introduction to arene electrophilic substitutions. Sulphonation/sulfonation to give a sulphonic/sulfonic acid like benzenesulphonic acid/benzenesulfonic acid, The orientation of products in aromatic substitution (1,2-; 1,3-; and 1,4- positions for two substituents in the benzene ring, old names - ortho/meta/para substitution products). The revision notes include full diagrams and explanation of the mechanisms and the 'molecular' equation and reaction conditions and other con-current reaction pathways and products are also explained for the reaction mechanisms of aromatic hydrocarbons like benzene and methylbenzene.
Part 10.8 AROMATIC HYDROCARBONS (Arenes)
10.8.1 Introduction to the reactivity of aromatic compounds
e.g. the arenes benzene and methyl benzene
Why do aromatic hydrocarbon molecules primarily react via electrophilic substitution reaction?
The five reactions described are electrophilic substitution reactions involving the generation of a powerful electrophile (electron pair acceptor) which subsequently attacks the electron rich Π (pi) electron system of the double bond. Arenes tend to undergo substitution, rather than addition, because substitutions allows the very stable benzene ring to remain intact.
10.8.6 The electrophilic substitution of an arene - sulphonation mechanism
The organic synthesis of sulfonic/sulphonic acids by reaction of benzene/methylbenzene with conc. sulfuric/sulphuric acid
mechanism 25 - electrophilic substitution by an acyl group in the benzene ring
10.8.7 The orientation of products in aromatic electrophilic substitution reactions
keywords phrases: reaction conditions formula intermediates organic chemistry reaction mechanisms electrophilic substitution benzene methylbenzene C6H6 + SO3 ==> C6H5SO2OH or C6H6 + H2SO4 ==> C6H5SO2OH + H2O R = CH3, benzene: C6H5CH3 + H2SO4 ==> CH3C6H4SO2OH + H2O sulfonation reaction is the substitution of -H by -SO2OH sulphonation
APPENDIX - COMPLETE MECHANISM and Organic Synthesis INDEX (so far!)