CH 220 1st Edition Lecture 13 Outline of Current Lecture I. Aromatic CompoundsII. Halogenation of benzeneIII. Common namesIV. Disubstituted benzenesV. Benzene’s Unusual StructureVI. Electrophilic Aromatic SubstitutionsCurrent Lecture I. Aromatic Compoundsa. Unsaturated compounds that undergo susbstitution rather than additionb. Have a benzene ringc. Distinguished from aliphatic (hydrocarbons)d. Common part of many structurese. Important in pharmaceuticals – good delivery agent – stays flat, no change in configurationII. Halogenation of benzeneThe Br or Cl gets substituted for an HNeeds an iron compound catalyst – FeBr3 for Br2 reactions, FeCl3 for Cl2 reactionsWithout the catalyst, nothing happensThe halogen can substitute any hydrogen on the ringThis is substitution and not additionIII. Naming aromatic compoundsa. Monosubstituents – put name of substituent in front of BenzeneThese 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.Lecture 11 Bromobenzene Nitrobenzene Propylbenzeneb. Common names (make sure these are on the worksheet – can use in exam)c.These common names can be used as parent names in larger compounds: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. CH 220 1st EditionLecture 11 2-bromotoluene 2,4,6-trinitrotoluene (TNT)If more than one common named group is present, use the name closest to the bottom of the list.IV. Disubstituted benzenesNamed for the relative positions of substituents on the benzene ring:Ortho has substituents in position 1,2 is written before the name ‘ortho-‘ or ‘o-‘Meta has substituents in position 1,3 is written before the name ‘meta-‘ or ‘m-‘Para has substituents in position 1,4 is written before the name ‘para-‘ or ‘p-‘When asked to name IUPAC, use #s for substituents, for common use o-, m-, p-V. Benzene’s Unusual StructureThe double bonds don’t act as individual bonds, they work as a benzene groupReactions of benzene lead to the retention of the aromatic coreVI. Electrophilic Aromatic SubstitutionsThese 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. CH 220 1st EditionLecture 11 The halogen can be Br2 or Cl2Needs a catalyst – FeBr3 or FeCl3Needs a catalyst – H2SO4Needs heatResults in benzenesulfonic acid and H2OUses an alkyl group attached to a Cl (has to be a Cl, no other halogen)The alkyl group could be any alkyl groupRequires a catalyst – AlCl3 (Friedel Craft Catalyst)Requires heatIt allows you to make a bond between two carbons, which has high commercial valueCarbonyl group reacts with benzene ring using AlCl3 (Friedel Craft Catalyst)Requires heat of at least 80CThe carbonyl group is very reactive and so ‘opens the door’ for the reaction to happenKnown as functionalization – attaching a functional group in order to extendThe carbonyl group can be attached to any alkyl group - small or largeThese 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. CH 220 1st EditionLecture 11 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. CH 220 1st