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Acyl chlorides contain the –COCl functional group, attached to an alkyl stem Acid anhydrides contain the –COOCO- functional group, attached to two alkyl groups

Hydrolysis of nitrile: Br KCN CN H3O + or 1) NaOH 2) H3O + CO2H SN2 Acid Chlorides Preparation from Carboxylic Acids: O OH SOCl2, pyridine CCl O

[PDF] Carboxylic acid deri

carboxylic acid ester amide acid chloride acid anhydride thioester acyl phosphate Increasing reactivity parent function group Chapter 21 8 please read 198

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Acyl chlorides contain the –COCl functional group, attached to an alkyl stem Acid anhydrides contain the –COOCO- functional group, attached to two alkyl groups

carboxylic acids

We were the first to obtain in high yields the pure acid chlorides of aliphatic B- ( chlorosulfinyl)carboxylic acids (I)-(IV) by the chlorination of the 8-(acetylthio)- and 8

Reactions of carboxylic acid chlorides with - springer link[]

which in principle can be effected as an equilibrium reaction for any pair made up of a disubstituted amide and a carboxylic acid chloride [2] Scheme 1 o // e

[PDF] Formamide Catalyzed Activation of Carboxylic Acids - The Royal

Herein, removal of one equivalent of HCl through evaporation of the reaction solvent after transformation of the carboxylic acid 1 into the respective acid chloride

A Mild and Efficient Procedure for the Preparation of Acid Chlorides

The conversion of carboxylic acids to acid chlorides is quite satisfactory in various common solvents used in organic synthesis such as toluene, acetonitrile, or

[PDF] Chapter 21: Carboxylic Acid Derivatives

all derivatives of carboxylic acids: R carboxylic acid ester anhydride acyl halides amides compounds with groups that that acid chloride are the most reactive

CarboxylicAcids,EstersandAcylChloridesCarboxylicacidscontainthe-COOHfunctionalgroup,attachedtoanalkylstem.Theyarewidelyfoundinnature,fromthemethanoicacidinants,theethanoicacidinvinegartothecitricacidincitrusfruits.Esterscontainthe-COO-functionalgroup,withanalkylgroupattachedtoeitherside. Estersarewidelyusedinperfumesandflavouringssincetheyareresponsiblefortheflavoursofmanyfoodsandthescentsofflowers.Acylchloridescontainthe-COClfunctionalgroup,attachedtoanalkylstem.Acidanhydridescontainthe-COOCO-functionalgroup,attachedtotwoalkylgroups.Theycanbeconsideredastwocarboxylicacidmoleculesjoinedtogetherbyacondensationwitheliminationofawatermolecule.Namingcarboxylicacids• namethealkylgroup,thenreplacethefinal'e'with'oicacid'.• rememberthatthecarboninthe-COOHgroupispartofthealkylchainfornamingpurposes,so:HCOOHismethanoicacidCH3COOHisethanoicacidetc. C6H5COOHisbenzoicacid• the-COOHgroupcanonlygoontheendofachain,sononumberingisrequiredtoidentifyitsposition.Likeinanaldehyde,thecarboninthe-COOHgroupbecomesnumber1inthechain.estersEsterscanbeconsideredasderivativesofcarboxylicacids,wherethehydrogeninthe-COOHgrouphasbeenreplacedwithanalkylgroup.Theesternamestartswiththenameofthisalkylgroup,thenthenamefromthecarboxylicacid,withthe'-oicacid'endingreplacedwith'-oate'.propoanoicacidmethylpropanoatee.g.CH3COOC3H7ispropylethanoateCH3CH2COOCH3ismethylpropanoateetc.C

O OH C O O C Cl O C O O C O C OH O

OCRChemistryAH432CarboxylicAcids,EstersandAcylChlorides Page 2 CH3COOC6H5isphenylethanoateC6H5COOC6H5isphenylbenzoateacylchloridesThesearesimilarlynamedasderivativesofcarboxylicacids.The'-oicacid'suffixisreplacedwith'-oylchloride'.Hence:CH3COClisethanoylchloride(pronounced-o-ile,not-oil!) CH3CH2COClispropanoylchlorideC6H5COClisbenzoylchlorideacidanhydridesThesetooarenamedasderivativesofcarboxylicacids.Thetwoalkylgroupsarethesame,sowesimplyremovethe'-oicacid'suffixandreplacewith'-oicanhydride'.CH3COOCOCH3isethanoicanhydrideetc. SolubilityofcarboxylicacidsShortchaincarboxylicacid(1-4carbons)arereadilysolubleinwater.TheycandissolveinwaterbecausethehighlypolarC=OandO-Hgroupsinthecarboxylicacidfunctionalgroupcanformhydrogenbondstothewatermolecules.Thealkylgroupisnon-polaranddoesnotinteractwiththewatermolecules.Diagram:Asthesizeofthealkylgroupincreasesthesolubilitydecreases,asthenon-polaralkylgrouphasagreatereffectontheoverallpolarityofthemolecule.Dicarboxylicacids,withtwo-COOHgroupsoneitherendofthechainarereadilysolubleinwater,havingtwopolarcarboxylgroupstoformhydrogenbondswiththewatermolecules.C

O OHO H H H OH : : δ+ δ+ δ- δ- C 3 H C O C CH 3 O O C 3 H C O Cl

OCRChemistryAH432CarboxylicAcids,EstersandAcylChlorides Page 3 AcidReactionsofCarboxylicAcids! Carboxylicacidsreactingwithmetalsandbases(metaloxides,hydroxidesandcarbonates)toformsalts.ThesesaltsareIONIC;themetalprovidingthepositiveionandthecarboxylicacidforminganegativecarboxylateion.! Carboxylicacidsareweakacids(partiallydissociatedinaqueoussolution).Thismeansthatcarboxylicacidsreactmoreslowlythanstrongacidsofthesameconcentration,astheconcentrationofH+inthesolutionislower.CH3CH2COOH⇌CH3CH2COO-+H+1)withreactivemetalscarboxylicacid+metal"metalcarboxylate(salt)+hydrogene.g.CH3COOH+Na"CH3COO-Na++½H2ethanoicacidsodiumethanoateObservations:• effervescence• themetaldissolvesEvaporationoftheresultingsolutionwillgivewhitecrystalsofsodiumethanoate2)withalkalis(metalhydroxides/ammoniasolution)carboxylicacid+metalhydroxide"metalcarboxylate(salt)+watere.g.CH3COOH+NaOH"CH3COO-Na++H2OObservations:• none-nofizzingetc.Thisisaneutralisationreaction.Anindicatorwouldbeneededtoseewhenthesolutionhadbecomeneutral.Crystalsofthesaltcanbeobtainedbyevaporation.3)withmetalcarbonatescarboxylicacid+metalcarbonate"metalcarboxylate+water+carbondioxidee.g.2CH3COOH+Na2CO3"2CH3COO-Na++CO2+H2OObservations:• fizzing• (solid)metalcarbonatedissolvesThisisaneutralisationreaction.Crystalsofthesaltcanbeobtainedbyevaporation.NOTE:Thereactionwithcarbonatesprovidesatestforcarboxylicacids.Otheracidicorganicmoleculessuchasphenolsarenotsufficientlyreactivetoreactwithcarbonates.

OCRChemistryAH432CarboxylicAcids,EstersandAcylChlorides Page 4 4)withmetaloxidescarboxylicacid+metaloxide"metalcarboxylate+watere.g.2CH3COOH+CuO"(CH3COO-)2Cu2++H2OObservations:• metaloxidedissolvesThisisaneutralisationreaction.Crystalsofthesaltcanbeobtainedbyevaporation.Practice:Writebalancedequationstoshowthereactionsofbutanoicacidwith:magnesium,calciumhydroxide,strontiumcarbonate,lithiumoxideReactions of carboxylic acids - esterification Esterificationisthereactionofacarboxylicacidwithandalcoholstoformanester. Estershavefruitysmellsandarefoundnaturallyinfruits.butylbutanoate-pineapple3-methylbutylethanoate-pearethyl2-methylbutanoate-appleEstersareusedtomakeartificialflavouringsandperfumes.Combinationsofesterscanbeusedtomimicsomeofthemorecomplexmixturesfoundinnature.Conditions:Warmthecarboxylicacidwiththealcoholinthepresenceofasmallamountofconcentratedsulphuricacidasacatalyst. Thereactionmixtureneedstoberefluxedbecausethereactionisfairlyslow.Separatingtheproduct:Thereactionisreversibleandatequilibriumtherewillbeproductsandreactantsbothpresent.Distillationisusedtoremovetheimpureesterfromthereactionmixture,beforepurification.Equations:conc.sulphuricacidcatalyste.g.CH3CH2COOH+CH3OH⇌CH3CH2COOCH3+H2Opropanoicacidmethanolmethylpropanoatewater Howitworks:TheH-fromthealcohol'sOHgroupandthe-OHfromthecarboxylicacidareremovedtomakewater.TheOfromthealcoholjoinstotheC=Oofthecarboxylicacidtoformanesterlink.

OCRChemistryAH432CarboxylicAcids,EstersandAcylChlorides Page 5 C H H H COH H H HO C O C H H HHC H H C H H O C O C H H H H O H

CH3CH2OH + CH3COOH ⇌ CH3COOCH2CH3 + H2O Note:Itisalsopossibleforamoleculecontainingbothanalcoholandacarboxylgrouptoreactwithitself,formingacyclicester,solongasthetworeactinggroupsarenottooclosetogetherthattheresultingringwouldbetoostrained. 4-hydroxybutanoic acid Practice:i)Usingdisplayedformulae,writeanequationforthereactionbetweenbutanoicacidandethanolinthepresenceofanacidcatalyst;nametheesterformedinthisreactionii)writeanequationfortheesterformedwhen5-hydroxyhexanoicacidiswarmedwithanacidcatalystReactionsofEstersEsterscanbehydrolysedtoformacarboxylicacid(oritssalt)andanalcohol.i)AcidhydrolysisConditions:heatunderrefluxdilutesulphuricacidorhydrochloricacidcatalystHCl(aq)Reaction:e.g.CH3COOCH2CH2CH3+H2O⇌CH3COOH+HOCH2CH2CH3propylethanoate+waterethanoicacid+propan-1-olii)AlkalinehydrolysisConditions:heatunderrefluxaqueoussodiumorpotassiumhydroxideDefinition:HydrolysisisareactionwithwaterorhydroxideionsthatbreaksachemicalcompoundintotwocompoundsHO

O OH O O conc. H 2 SO 4

OCRChemistryAH432CarboxylicAcids,EstersandAcylChlorides Page 6 Thereactioninthiscaseisnotreversible,andleadstotheformationofthesodiumsaltofthecarboxylicacid.CH3COOCH2CH2CH3+NaOH"CH3COO-Na++HOCH2CH2CH3propylethanoate+sodiumhydroxidesodiumethanoate+propan-1-olThisisthereactionthatisdoneinsoap-makingtoturnfatsintosoaps-calledsaponification.Practice:Butylhexanoatecanbehydrolysedwithaqueousacidorwithaqueousalkali.-drawthestructureofbutylhexanoate-writeequationsfortheacidandalkalinehydrolysisReactionsofAcylChlorides• Acylchloridesareveryreactive.Theyareusefulinorganicsynthesisastheyreacttoformcarboxylicacidderivatives:esters,amidesetc.withgoodyields.• Acylchloridesreactwithnucleophilesundergoingsubstitutionreactionsinwhichthecarbonylgroupisretained,andachlorideioneliminated.Preparationofacylchlorides:Acylchloridesaremadefromthecorrespondingcarboxylicacidsbyreactingthemwiththionylchloride,SOCl2.TheotherproductsareHClandSO2,whichasgaseswhichcanbeallowedtoescape(harmful!-inafumecupboard)leavingtheacylchlorideproduct.e.g.CH3CH2COOH+SOCl2"CH3CH2COCl+SO2+HClpropanoicacidthionylchloridepropanoylchlorideReactionwithwater:Whenwaterisaddedtoanacylchloride,aviolentreactiontakesplacewiththereleaseofsteamyfumesofhydrogenchloride.Acarboxylicacidisformed.e.g.CH3COCl+H2O"CH3COOH+HClethanoylchlorideethanoicacidMechanism:Inthefirststage:• Nucleophilesarelone-pairdonors.Thelonepaironthenucleophileisusedtoformadativebondtotheδ+carbonofthecarbonylgroup,anadditionstep.• Atthesametimethepi-bondoftheC=Obreaksheterolytically,formingC-O-.Inthesecondstage:• TheC=ObondreformsusingalonepairfromtheoxygenoftheC-O-.• TheC-Clbondbreaksheterolytically,eliminatingachlorideion,Cl-.

OCRChemistryAH432CarboxylicAcids,EstersandAcylChlorides Page 7 C 3 HC O Cl H O H C 3 HC O Cl O H H C 3 HC O OH Cl OCRChemistryAH432CarboxylicAcids,EstersandAcylChlorides Page 8 CH 3 O OCH 2 CH 2 CH 3 HO O CH 3

Equation:e.g.ethanoicanhydride+propan-1-ol"propylethanoate+ethanoicacidPractice:i. Writeanequationusingdisplayedformulaeforthereactionbetweenanacidanhydrideandanalcoholwhichwouldallowyoutomaketheestermethylpropanoate.ii. Writeanequationusingskeletalformulaeforthereactionbetween4-methylphenolandpropanoicanhydridetoform4-methylphenylpropanoate.O

O CH 3 O CH 3 HOCH 2 CH 2 CH 3quotesdbs_dbs17.pdfusesText_23

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