氢氧化钠氯气,碘仿反应

Org.Synth.1937,17,65p-NAPHTHOICACID[2-Naphthoicacid]

SubmittedbyM.S.NewmanandH.L.Holmes.

CheckedbyW.W.HartmanandF.W.Jones.

Procedure

Ina3-l.flaskisplacedasolutionof184g.(4.6moles)ofsodiumhydroxidein300-400cc.ofwater;sufficienticeisaddedtomakethetotalvolumeabout1.5l.Chlorineispassedintothesolution,thetemperaturebeingkeptbelow0°bymeansofasalt-icebath,untilthesolutionisneutraltolitmus,thenasolutionof34g.ofsodiumhydroxidein50cc.ofwaterisadded(Note1)and(Note2).Theflaskisnowsupportedbyaclampandequippedwithathermometerandanefficientstirrer.Thesolutioniswarmedto55°and85g.(0.5mole)ofmethylp-naphthylketone(Note3)isadded.Themixtureisvigorouslystirred,and,aftertheexothermicreactioncommences,thetemperatureiskeptat60-70°(Note4)byfrequentcoolinginanicebathuntilthetemperaturenolongertendstorise.Thisrequiresthirtytofortyminutes.Thesolutionisstirredforthirtyminuteslongerandthentheexcesshypochloriteisdestroyedbyaddingasolutionof50g.ofsodiumbisulfitein200cc.ofwater(Note5).Aftercoolingtoroomtemperature,thereactionmixtureistransferredtoa4-l.beakerandcarefullyacidifiedwith200cc.ofconcentratedhydrochloricacid.ThecrudecolorlessacidiscollectedonaBuchnerfunnel,washedwithwater,andsuckedasdryaspossiblewitharubberdam.Afterdrying,theacidiscrystallized(Note6)from600cc.of95percentalcohol,giving75-76g.(87-88percentofthetheoreticalamount)ofp-naphthoicacidmeltingat184-185°(corr.).Bydistilling450cc.ofsolventfromthemotherliquor,anadditional9g.(10percentofthetheoreticalamount)ofacid,m.p.181-183°(corr.),isobtained(Note7).

Notes

Itisreportedthat,inpreparingasodiumhypochloritesolutionbypassingchlorineintosodiumhydroxide,itisverydifficulttodeterminetheneutralpointbecauseoftheinstantbleachingoftheindicator.Iftoomuchchlorineisadded,eventhoughthefinalsolutionmayreactalkalinebecauseoftheadditionalsodiumhydroxideaddedlater,oxidationofmethylp-naphthylketonetop-naphthoicaciddoesnottakeplace.Consequentlythefollowingmodifiedprocedureforpreparingthehypochloritesolutionisrecommended.

Asolutionof218g.(5.45moles)ofsodiumhydroxidein300cc.ofwaterina3-l.flaskiscooledtoroomtemperaturewithtapwater.Next,1250g.oficeisaddedanchlorineispassedinrapidlyuntil161g.(4.5moles)hasbeentakenup.Externalcoolingisunnecessary.Withtheamountoficespecified,thesolutionwillbeat0°whentheadditionofchlorinehasbeencompleted.Fromthispointontheprocedureisthesameasthatonp.428.(PrivatecommunicationfromEdwardC.Sterling.)

ThehypochloritesolutionalsomaybepreparedconvenientlyfromthecalciumhypochloritesoldbytheMathiesonAlkaliWorksunderthetradename"HTH"andspecifiedtocontainnotlessthan65percentofavailablecalciumhypochlorite.

Ina3-l.round-bottomedflask250g.ofcommercialcalciumhypochloriteisdissolvedin1l.ofwarmwater,andawarmsolutionof175g.ofpotassiumcarbonateand50g.ofpotassiumhydroxidein500cc.ofwaterisadded.Theflaskisstopperedandshakenvigorouslyuntilthesemi-solidgelwhichfirstformsbecomesquitefluid.ThesuspendedsolidisremovedbyfiltrationonalargeBichnerfunnel,washedwith200cc.ofwater,andsuckedasdryaspossiblewiththeaidofarubberdamandanefficientsuctionpump.Thefiltrateofapproximately1.5l.isplacedina3-l.round-bottomedflaskandisreadyfortheadditionofmethylp-naphthylketone.

Suchasolutioncontainsapproximately200g.(2.3moles)ofpotassiumhypochlorite.Sodiumorpotassiumhypochloritemaybeused,butthecalciumsaltisnotsatisfactorybecausethecalciumsaltofp-naphthoicacidissparinglysoluble.

TheEastmanproduct,m.p.53-55°,wasused.

Ifthemixtureisnotcooled,thereactionwillgetoutofcontrolbecauseoftherapidevolutionofchloroform,andsomeketonemaysteam-distil.

Itisadvisabletotestthesolutionaftertheadditionofthesodiumbisulfitewithacidifiedpotassiumiodidesolutiontobesurethatallthehypochloritehasbeendestroyed.Ifhypochloriteispresent,thechlorineliberatedwhenthesolutionisacidifiedformsahigh-meltingimpurity.

Themoistacidmaybecrsytallizedwithoutdrying,butmorealcoholmustbeusedtogettheproductintosolution.

Thismethodmaybeusedforthepreparationoflargerquantities,abatchtwentytimesthissizegivingayieldof87percent.Itmaybeusedalsoforthepreparationofotheraromaticacidswheresuitableketonesareavailable.

Discussion

P-Naphthoicacidhasbeenpreparedprincipallybythehydrolysisofp-naphthonitrile,1theover-allyieldsfromp-naphthylamine,fromsodiump-naphthalenesulfonate,and什omcalciump-naphthalenesulfonatebeinggivenas(approximately)20percent,21percent,and50percent,respectively.2TheacidhasbeenpreparedalsobythecarbonationoftheGrignardreagentfromthelessaccessiblep-bromoderivativesbychlorinationofp-methylnaphthalenefollowedbyhydrolysisandoxidation*andbytheproceduredescribedabove.5Thevariousmethodsforpreparingp-naphthoicacidhavebeendiscussedbyWahl,Goedkoop,andHeberlein.4

Thispreparationisreferenced什om:

.Org.Syn.Coll.Vol.3,302

.Org.Syn.Coll.Vol.4,484

.Org.Syn.Coll.Vol.6,78

.Org.Syn.Coll.Vol.8,26

ReferencesandNotes

BaeyerandBesemfelder,Ann.266,187(1891).

DerickandKamm,J.Am.Chem.Soc.38,408(1916).

GilmanandSt.John,Rec.trav.chim.48,743(1929).

Wahl,Goedkoop,andHeberlein,Bull.soc.chim.(5)6,533(1939).

Fieser,Newman,andHolmes,J.Am.Chem.Soc.58,1055(1936).

ExampleTitleStepA-2

StepA-2

Preparationof4-(4-Bromobutyl)benzoicAcid

Asolutionofsodiumhydroxide(163.7g.,4.092moles)inwater(1400ml.)anddioxane(1000ml.)iscooledto15.deg.

C.andtreatedduring30minuteswithbromine(