Chapter22AminesTheimportantorganicreactionsofamines(nucleophiles)arewiththecommonelectrophiles:alkylhalidesvianucleophilicsubstitution,aldehydesorketonesvianucleophilicadditioncarboxylicacidderivatives,especiallyacidchloridesoranhydridesvianucleophilicacylsubstitution.§22.1NomenclaturePrimaryaminesarenamedintheIUPACsysteminseveralwaysdependingontheirstructure.Forsimpleamines,thesuffix-amineisaddedtothenameofthealkylsubstituent.Alternatively,thesuffix–aminecanbeusedinplaceofthefinal–einthenameoftheparentcompound.Insecondaryandtertiaryamines,thealkylgroupsmaybethesameordifferent.Compoundswithfourgroupsattachedtonitrogenarealsoknown,butthenitrogenatommustcarryapositivecharge.Suchcompoundsarecalledquaternaryammoniumsalts.An-NH2group,whennottheprincipalgroup,isnamedbytheprefixamino-.Symmetricalsecondaryandtertiaryaminesarenamedbyaddingtheprefixdi-ortri-tothealkylgroup.UnsymmetricallysubstitutedsecondaryandtertiaryaminesarenamedasN-substitutedprimaryamines.Thelargestalkylgroupischosenastheparentname,andtheotheralkylgroupareconsideredN-substituentsontheparent(Nsincethey’reattachedtonitrogen).§22.2StructureandBondingStructureandBondinginAmineChenliChenliThisisaresultofresonancedelocalisationofthelonepairintothearomaticpsystem(suchdelocalisationisalsoresponsibleforthedecreasedbasicityofarylvsalkylamines).§22.3PhysicalpropertiesofAmineshighmeltingandboilingpointscomparedtoanalogousalkaneshighsolubilityinaqueousmediaAminesarehighlypolarandthereforehavehigherboilingpointsthanalkanesofequivalentmolecularweighthave.Likealcohols,amineswith<C5aregenerallywater-soluble.Primaryandsecondaryaminesformstronghydrogenbondsandarehighlyassociatedintheliquidstate.§22.4BasicityofAminesBasicityofSomeAmines§22.5PreparationofAminesAminesviaReductionAminesviaReduction:ASummaryAminesviaRearrangement22.5.1AlkylationofAmmoniaorAminesMechanismofAmmoniaAlkylationAmmoniareactsasanucleophilewithalkylhalidestogiveprimaryaminesinasubstitutionreaction.Yieldsareoftenpoorastheproduct,aprimar