I. Nomenclature of Benzene SubstituentsII. Electrophilic Addition Reactions involving BenzeneIII. Further Reactions to Know Involving BenzeneI. Sulfonation Reaction to KnowII. Reverse SulfonationIII. Friedel Crafts AlkylationIV. Intramolecular Reaction AlkylationI. Sulfonation Reaction to Knowa. Benzene + sulfuric acid in SO3 (special reagent)  benzene with SO3H substituenti. Special reagent is called “fuming sulfuric acid” or Oleum (SO3)b. Mechanism:i. 1. Make electrophile: (next page)ii. Do electrophilic addition substitutionII. Reverse Sulfonationa. When you have sulfuric acid in water, you assume that hydronium ions are present in solutionb. To do a reverse sulfonation, you must add sulfuric acid in water and HEAT.c. The mechanism:i. Pi electrons de-protonate hydronium ion, leaving water and a carbocation.ii. Electrons from O-H in HSO3 substituent move to S-O bond to form a third pi bond between S and O, and therefore kick off of the carbocation, where prior electrons move to remake the pi bond in the benzene ring:III. Friedel Crafts Alkylationa. Means of adding Carbon to benzeneb. Alkyl = sp3 Cc. Simplest example: make toluenei. Benzene + CH3Cl + AlCl3 toluene (benzene with methyl substituent)1. AlCl3 is an excellent Lewis acid, and a catalyst for this reactionii. 1. Make electrophile:1. Cl electrons of CH3 – Cl (C has a moderately partial positive charge) attack Al in AlCl3, creating H3C – Cl – AlCl3 (C has enhanced partial positive charge)…center Cl has FULL BLOWN POSITIVECHARGE (thus you’ve made your electrophile)2. Do electrophilic addition substitution:a. Pi electrons in benzene ring attack “enhanced” partial positive charged C inH3C – Cl – AlCl3b. Carbocation formsc. Electrons in Cl – AlCl3 DE-PROTONATE H, electrons move to re-form pi bond in benzene ring. You have formed toluene and regenerated AlCl3d. Note*** You cannot isolate this carbocation because no free carbocation intermediate forms. This reaction is therefore very hard to stop.iii. If you had a secondary or tertiary Cl, then you get a free carbocation that you can isolate. Recall that secondary and tertiary carbocations are relatively stable.IV. Intramolecular Reaction Alkylationa. Benzene with long haloalkyl group + AlCl3i. Mechanism below:CHEM 0320 1st Edition Lecture 8Outline of Last Lecture I. Nomenclature of Benzene Substituents II. Electrophilic Addition Reactions involving Benzene III. Further Reactions to Know Involving Benzene Outline of Current Lecture I. Sulfonation Reaction to Know II. Reverse Sulfonation III. Friedel Crafts Alkylation IV. Intramolecular Reaction Alkylation Current LectureI. Sulfonation Reaction to Know a. Benzene + sulfuric acid in SO3 (special reagent)  benzene with SO3H substituent i. Special reagent is called “fuming sulfuric acid” or Oleum (SO3)b. Mechanism: i. 1. Make electrophile: (next page)These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.1.ii. Do electrophilic addition substitution 1.II. Reverse Sulfonation a. When you have sulfuric acid in water, you assume that hydronium ions are present in solution b. To do a reverse sulfonation, you must add sulfuric acid in water and HEAT. c. The mechanism: i. Pi electrons de-protonate hydronium ion, leaving water and a carbocation.ii. Electrons from O-H in HSO3 substituent move to S-O bond to form a third pi bond between S and O, and therefore kick off of the carbocation, where prior electrons move to remake the pi bond in the benzene ring:III. Friedel Crafts Alkylation a. Means of adding Carbon to benzene b. Alkyl = sp3 C c. Simplest example: make toluenei. Benzene + CH3Cl + AlCl3 toluene (benzene with methyl substituent) 1. AlCl3 is an excellent Lewis acid, and a catalyst for this reactionii. 1. Make electrophile:1. Cl electrons of CH3 – Cl (C has a moderately partial positive charge)attack Al in AlCl3, creating H3C – Cl – AlCl3 (C has enhanced partial positive charge)…center Cl has FULL BLOWN POSITIVECHARGE (thus you’ve made your electrophile)2. Do electrophilic addition substitution: a. Pi electrons in benzene ring attack “enhanced” partial positive charged C inH3C – Cl – AlCl3b. Carbocation formsc. Electrons in Cl – AlCl3 DE-PROTONATE H, electrons move to re-form pi bond in benzene ring. You have formed toluene and regenerated AlCl3d. Note*** You cannot isolate this carbocation because no free carbocation intermediate forms. This reaction is therefore very hard to stop.iii. If you had a secondary or tertiary Cl, then you get a free carbocation that you can isolate. Recall that secondary and tertiary carbocations are relatively stable.IV. Intramolecular Reaction Alkylation a. Benzene with long haloalkyl group + AlCl3i. Mechanism