C1-Allens Made Chemistry Theory {PART-1}

Another reasons is : The intermediates when an electrophile attack on alkene and alkynes are :(i)R—CC—R+HRC HCR +(ii)R—CHCH—R+HRCH CHHR+Stability of intermediates :R—CH C —R<R—C H —2CH —R(+) ve on more ENmore stableatoms is less stableSo we can say that alkenes are more reactive towards electrophilic addition reaction.( a )Addition of hydrogen : Alkynes reacts with hydrogen in presence of a catalyst.In presence of Pt., Pdor Ni alkynes give alkanes with H2R—CCH 2 Ni, H300 CR—CHCH22 Ni, H300 CR—CH —CH23In presence of Lindlar's catalyst [3 Pd / CaCO+ quinoline or Nickle boride] alkynes give cis – alkeneR—CC—R'2Lindlar's catalystHRCCR'HH(Stereo specific reaction) cis - alkeneIn presence of Na/NH alkynes give trans-alkene. (Birch Re-cuction)3R—C C—R'32Na / NHHRCCHHR'(Stereo specific reaction) trans-alkene( b )Addition of Halogens : Reactivity order of HalogensCl > Br > I222Alkynes react with Cl or Br in dark in presence of metal halide and form di and tetra halo derrivatives.22R—CCH232ClFeClRClC CClHClClMechanism :Cl + FeCl23Cl + +–4 FeClRC CH ClRC CH RC CHCl +: : Cl..less stable(Incomplete octet)of (+) ve C–atom)More stable(Complete octet)of (+) ve Cl–atom)RC ClCH + FeCl3ClRClC CClHClCl[FeCl ]4FeCl Cl32(Product)(Tetrachloride)(Cyclic cation is intermediate)+

Acetylene tetrachloride is also called as westron.When westron is treated with Ca(OH) then we get westrosol2Both westron and westrosol are used as solvents in cloth industries+ Ca(OH)2–HClCHClCCl2Westrosol or tricleneH C C HCl ClCl ClReaction with dilute Br or bromine water:2CHCH + Br22H OBr—CHCH—BrCHCH + Br2liquidBrC C—BrH HBr BrReaction with Iodine :CHCH + I2ethanolCHICHI (addition reaction)CHCH + I23 NHI—CC—I + NH I (substitution reaction)4Di iodoacetylene( c )Addition of halogen acids (H – X) : Addition according to Markowni-Koff's Rule.Reactivity order of H – X : HI > HBr > HCl > HFR—CC—HH X RH C CHHXX(Gem dihalides major product)Mechanism :R—CCHH[H X]RH C CH+(Intermediate is carbocation)R—C CH2–XRC XCH 2FurtherRC XCH 2H RC XCH 2H +RC XCH 2H(more stable(only –I of X)due to +M of X)soRC XCH 3+XRC XCH 3X(Major Product)

( d )Addition of HOX : Alkynes react with hypohalous acids according to markownikoff's rule and formgem diol, which are unstable, lose a molecule of water and form halo aldehyde or halo ketones.Reactivity order HOCl> HOBr > HOIRC CH + HOClR COCHCl2Mechanism :R—C CH Cl[HOCl]R: :C lC CH +..RClC CH+(Cyclic cation)RClC CH+HO RCOHCHClFurtherRCOHCHClClRC CHClCl OH+RCCHCl OHCl(more stable due(less + M of Cl - Atom)to +M of OH group)soRCClCHCl OH+HO RCCHCl2OHOH2H OR COCHCl2(Unstable)(Dichloro ketones)( e )Addition of BH / THF or B H (Hydroboration) : THF - Tetrahydrofurane is used as solvent.3263R—CC—R3 BHTHF(R CC ) BH R3Since BH is not available as monomer so a solvent THF is used for the stability of BH .33RC C R + B HHH –+ – – – +R CH CBH 2RR CH C BH + 2R C C2 RR(R CH C ) B3R(R CC ) BH R3HO( OH)22Basic oxidation(R C C OH + B(OH)H R3RCH 2COR(Ketones)(enol form)CCH HH HO/ 2RR+ B(OH)3(cis-Alkene)–+

Example : CH —C3C—CH33 BHTHF(CH C C ) B3H CH3322H O /HOCH 3CH C OHCH 3CH 3CH 2CCH 3O(enol form(keto formless stable) more stable)( 2 )Nucleophilic addition reaction : In these reactions some heavy metal cation like Hg , Pb , Ba are used.+2+2+2These cation attracts the  – e of alkynes and decrease the e density and hence a nucleophile can attack an––alkynes.( a )Addition of dil. H SO (Hydration) : The addition of water takes place in the presence of Hg and24+2H SO [1% HgSO +40% H SO ]. In this reaction carbonyl compounds are obtained .24424CH CH + H—OHCH2CH—OHCH —CHO3enol unstableCH —C3CH + H—OH CH 3C CHOH HCH 3C CH3Oenol (unstable)A structure in which –OH group is attached to double bond carbon is called as enol (ene + – ol).This reaction is used for preparation of aldehyde and ketone.R—C CH 244Hdil.SO (1% )dil. HgSO (40% )R C CH3OMechanism :R—CCH 2HgR CCH:Hg+RC CHHg +2R C CHHg +2H O H....RCCHHgH OH –HRCCHHgOH H–Hg+2RCCHHOHRC CH3O(enol)(Keto more stable)+++++Example : CH —C3C—CH322H / H OHgCH 3CC CHHOH3CH 3CCH 2OCH 3 2-butanone( b )Addition of HCN : The addition of HCN in presence of barium cyanide to form vinyl cyanide.CHCH + HCN 2 Ba(CN)CH2CHCNThe vinyl cyanide is used for making polymers such as orlon and Buna-N rubber.CH2CHCN PolymerisationCH 2CNCH )(n Orlon

( c )Addition of acetic acid : Acetate acetylene combines with acetic acid in presence of murcuricsulphate.It first forms vinyl acetate and then ethylidene acetate.CHCH + OOCCH3H2HgCHOOCCH3CH 23CH COOHCH(OOCCH)3 2CH 3vinyl acetateEthylidene acetateCH 2CHOC CH3OCH 2O CCH )(nCH 3OCH 2OHCH ) + nCHCOOH(n3PolymerisationHydrolysisVinyl Acetate(Monomer)Poly vinyl acetate(Polymer : adhesive compound)Poly vinyl alcoholWhen ethylidene acetate is heated it give acetaldehyde and acetic anhydrideOCCH 3OCH CH 3OCCH 3O CHO + CH 3CH 3C OCH 3COO( d )Addition of alcohols : In presence of BF and HgO alkynes react with alcohols and form acetal and ketal3CHCH + CH OH 33 BFHgOCH2CHOCH 33CH OHCH 3CHOCH3OCH3 Methylal (acetal)R—CCH + CH —OH 33 BFHgOR CCH 2OCH33CH OHR CCH 3OCH3OCH3 KetalAcetylene forms acetal while other alkynes form ketal.( 3 )Addition of AsCl : In presence of AlCl or HgCl acetylene combines with AsCl to yield Lewisite gas. It is3323four times poisonous than mustard gas.CHCH + Cl—AsCl 2CH ClCHAsCl22-Chlorovinyl dichloro arsine (Lewisite gas)The action of Lewsite may be checked by its antidote BAL (British Anti Lewisite). BAL combines with theLewisite to form a cyclic non toxic compound.CH 2CH CH2SH SHOH2, 3–Dimercapto–1–propanol [BAL]

( 4 )Carbonylation : Reaction of alkynes with CO in presence of Ni(CO)4Alkyne + CO + H O24 Ni(CO)Olefinic acidAlkyne + CO + R–OH4 Ni(CO)Olefinic esterCHCH + CO + H O24 Ni(CO)CH 2CHCOOHAcrylic acidCHCH + CO + R HO4 Ni(CO)CH 2CHCOORAlkyl acrylateOxidation reactions :( a )Combustion :C Hn2n-2 + 3n 12O 2nCO + (n-1) H O + Heat222HCCH + 5O24CO + 2H O + 312 K.cal22The combustion of acetylene is used for welding and cutting of metals in which oxy-acetylene flame having hightemp (30000C) is produced.( b )Oxidation with alkaline KMnO : Oxidation with alkaline KMnO gives carboxylic acids.44CHCH+4[O]4 alk.KMnOCOOHCOOHAcetyleneOxalic acidCH —C3CH + 4[O]4 alk.KMnOCH —COOH + HCOOH3( c )Oxidation with acidic KMnO or K Cr O : In presence of acidic KMnO or acidic K Cr O . Alkynes4227 4227are oxidised to monocarboxylic acids.R—CC—R' + 2[O] R CO OC R'2H O [O]RCOOH + R'COOHCHCH + 2[O]CHOCHO2H O [O]2HCOOHglyoxalCH —C3CH + 2[O] CH 3COCHO2H O [O] CH COOH + HCOOH3Ex.An alkyne on oxidation with acidic KMnO , only acetic acid is obtained what is given alkynes ?4Sol. In Oxidation of alkynes two moles of mono carboxylic acids are obtained.CH 3C OH + HOOOC CH3332 ButyneCH — C — C — CH—

( d )Oxidation with selenium dioxide : Selenium dioxide oxidises alkynes to the dicarbonyl compounds.CHCH22[O]SeOCHOCHOGlyoxalCH 3CCH 3C22[O]SeOCH 3COCH 3CO2–ButyneButane - 2, 3 -dione( e )Oxidation with ozone (O ) : In the ozonolysis both sp-C-atoms are converted into 3CO OCgroup.R CC R + O3RCCO OROR CC R + HOO O22RCOH+ R COOHO Ozonide (Addition of ozone)(Acids)In this reaction H O is oxidant which oxidise 22RCCO OR into acids.But if we use some amount of Zn as reductant with H O then it reduce H O so oxidation does not take place222H O + Zn 22ZnO + H O2Example :CH C3CH(i) O3(ii) H O2CH 3CCO OH+ H O22CH 3C OH + HCOOHOCH 3CC H+ ZnOO O(i) O3(ii) H O/Zn2Substitution Reaction : (Formation of metallic derivatives)Only 1-alkynes give substitution reaction and show acidic characters–C — H Acetylene is dibasic acid where as propyne is monobasic means acetylene can give two H where as propyne+can give one H .+( a )Formation of sodium acetylides : Acetylene and 1-alkynes react with sodamide to form acetylidesH—CC—H2 NaNHNaCC —H2 NaNHNaCCNaMono sodiumDisodium acetylide acetylideDry alkynides are generally unstable and explosive. These are easily converted in to original alkynes whenheated with dilute acids.NaCCNa + 2HNO 3 HCCH + 2NaNO3This reaction can be used for the purification, seperation and identification of 1-alkynes.

( b )Formation of copper and silver acetylides : Copper and silver acetylides are obtained by passing1-alkynes in the ammonical solution of cuprous chloride and silver nitrate (Tollen's reagent) respectivley.R—CC—H + Cu Cl + NH OH 224R—CCCu + NH Cl + H O42ammonical cuprous- copper acetylidechloride[Red ppt.]R—CC—H + AgNO + NH OH 34R—CCAg + NH NO + H O432Tollen's reagentWhite ppt.These reactions are used for detecting the presence of acetylenic hydrogen.These are test for distinguishalkenes and alkynes or 1-alkynes and 2-alkynes.Isomerisation : When alkyne-1 is heated with alc. KOH alkyne-2 is obtained.CH —CH —C32CHalc.KOHCH —C3C—CH31–Butyne 2–ButyneWhen alkyne -2 is heated with NaNH alkyne -1 is obtained2CH —C3C—CH32 NaNHCH —CH —C32CH2–Butyne1–ButynePolymerisation :( a )Linear polymerisation :Dimerisation : When two molecules of acetylene passed through a solution of Cu Cl and NH Cl a224vinyl acetylene is obtained.2HC C—H224Cu ClNH ClCH2CH—CC—Hmono vinyl acetyleneWhen vinyl acetylene react with HCl then chloroprene is obtained.CH2CH—CC—H HClCH 2CH C CHCl2Polymerisation Neoprenee (Synthetic rubber)p re n2- chloro-1,3-butadiene[chloroprene]Trimerisation : 3 molecules of acetylene.3CHCH 224Cu ClNH Cl CH2CH—CC—CHCH2Divinyl acetylene( b )Cyclic polymerisation : When alkyne is passed through red hot metallic tube, cyclic polymerisationtakes place with the formation of aromatic compound3CHCHRe d hotiron tubeBenzene3 CH —C3CHRe d hotiron tubeCH 3HC3CH 3Mesitylene3 CH —C3C—CH3Re d hotiron tubeCH 3CH 3CH 3CH 3CH 3CH 3Hexa methyl benzene

3 HCCH465 3(Ni(CO)C H ) P(triphenyl–1–phosphene)benzene (90% yield)4CHCH2 Ni(CN)HCHCCHCHCH CHCH CH 1,3,5,7–cyclooctatetraeneOther reactions of acetylene :NH 3Electric spark2HCNNH 3HCNCHN ,22CHN22SHigh temp.Red hot Fe–N 2cold ether solutionAl O, 400°C23CHCHCHCHNH PyrolePyridineCHCHCH 2Cyclo propeneCHN22–N 2CH ——––––CHCH 2CH 2Bicyclo (1,1,0) butaneCH CHCHNNH H 2CH 2CH N2CHNHPyrazolineCH CHCHCHSThiopheneHCCH..N ..........(v i)Reaction with HCHO : This reaction is called ethynylation.CHCH + HCHO CuHCCCH —OH2HCHOOHOHCC CHCH 22 propargyl alcohol(vii)Reaction with NaOCl : (Substitution reaction)H — CC—H + NaOCl 0 Cabsence of air and lightH—CC—Cl + NaOHH—CC—Cl + NaOCl 0 Cabsence of air and lightCl—CC—Cl + NaOHDichloro acetylene

Uses of Acetylene :(i)Oxyacetylene flame used in welding and cutting(ii)Acetylene is used as an illuminant(iii)Acetylene is used for artificial ripenning of fruits(iv)Used for manufacture of acetaldehyde, acetic acid, ethyl alcohol, westron, westrosol, PVC, PVA,Chloroprene, butadiene, Lewisite etc.(v)It is used as a general anaesthetic.Laboratory Test for alkynes : FunctionalReagentObservation ReactionR e ma r k s Group(1) Bayer'sPink ColourCH =CH +H O+O 2224 alk.KMnOReagentdisappearsOH OHCH–CH22 Hydroxylationalk.dil.Cold KMnO4– C C –(2) Br /H O22Red ColourdecolourisesBr +CH =CH 222BrCH–CH22BrWhite pptBromination(3) O (ozone)3Acid FormedR–C C–R'3 ORCOOH+R'COOH OzonolysisLaboratory test of terminal alkynes :When triple bond comes at the end of a carbon chain. The alkyne is called a terminal alkyne.acetylenic hydrogenH –C C–CHCH231-Butyne, a terminal alkyne Functional GroupReagentObservation Reaction(1) Cuprous chlorideRed ppt.R–C CH+CuCl NHOH4R–C C Cu (red)+ NH OH4R–C C–H(2) AgNO +NH OH34White ppt.R–C CH+Ag'  R–C C Ag (white)(3) Na in etherColourless gasHC CH + 2Na  Na – C C – Na + H 2(i)Decolourization of Br in CCl solution.24(ii)Decolourisation of 1% alkaline KMnO solution.4(iii)1- alkynes give white ppt. with ammonical AgNO and red ppt with ammonical cuprous chloride3solution.

Note :(i) and (ii) tests are used for determination of unsaturation (i.e, presence of double or triple bond in anycompound)(iii) Test is used for distinguish between alkenes and 1-alkynes or 1-alkyne and 2-alkyne.Seperation of ethane, ethene and ethyne :Passed through ammonical Cu Cl22red pptCuC CCuGaseous mixture(C H + CH)2624KCN solutionEthyneconc. HSO24Ethyl sulphateEthane (Gas)Ethene[C H + CH + CH]222426

SOLVED EXAMPLESEx.R—CH —CCl —R 22agentRe R—C C—R. The reagent is -(A) Na(B) HCl in H O2(C) KOH in C H OH25(D) Zn in alcohol.Ans.(C)Sol.Alcoholic KOH brings about dehyrohalogenationEx.Acetylene when treated with dilute HCl at 60 C (333 K) in presence of HgCl produces -02(A) Methyl chloride(B) Vinyl chloride(C) Acetaldehyde(D) FormaldehydeAns.(B)Sol.(B) H–C C – H + HCl 2 HgCl60 CH = CH – Cl2 Vinyl chlorideEx.When propyne is treated with aqueous H SO in the presence of HgSO , the major product is -244(A) Acetaldehyde(B) Propanal(C) 2-Propanol(D) PropanoneAns.(D)Sol.CH – C CH + H O 32CH 3CCH 2OHCH 3COCH 3Ex.Alkaline KMnO , oxidizes acetylene to -4(A) Acetic acid(B) Glyoxal(C) Oxalic acid(D) Ethylene glycolAns.(C)Sol.H – C C – H + 4[O] COOHCOOHEx.Which of the following is most acidic -(A) Ethyne(B) Propyne(C) 1-Butyne(D) 2-ButyneAns.(A)Sol.Because ethyne gives most stable anion.Ex.Ozonolysis of acetylene gives -(A) Oxalic acid(B) Ethylene glycol(C) Glyoxal(D) CH CHO3Ans.(C)Sol.HC CH 32(i)O(ii) H O/ ZnH C C HO OGlyoxalEx.Propyne on reaction with aqueous chlorine gives -(A) 1, 1, 2, 2-Tetrachloropropane(B) 1, 2-Dichloropropene(C) 1, 1-Dichloropropanone(D) 2, 2-DichloropropanoneAns.(C)Sol.CH –C CH + 2HOCl 3CH 3CHCl2COHOH 2H OCH–C–CHCl32OEx.Mesitylene can be obtained by polymerization of -(A) Ethyne(B) Ethene(C) Propene(D) PropyneAns.(D)

Sol.Propyne on trimerization yields mesitylene 3CH C CH 3H C3CH 3CH 3MesityleneEx.Excess of CH COOH is reacted with CH CH in presence of Hg , the product is -32+(A) CH CH(OOCCH )33 2(B) CH = CH(OOCCH )23(C) (CH COO)CH —CH (OOCCH )3223(D) None of theseAns.(A)Sol.H–C C–H + 2CH COOH 3 CH – CH(OCOCH )33 2Both the protons go to same carbon atomEx.A compound is treated with NaNH to give sodium salt. Identify the compound -2(A) C H22(B) C H66(C) C H26(D) C H24Ans.(A)Sol.Ethyne is acidic in characterH–C C–H + NaNH 2 H – C C Na + –+12H 2



ALCOHOL, PHENOL & ETHERHydroxy derivativesAliphatic hydroxy derivativesAromatic hydroxy derivatives( I )Aliphatic hydroxy derivatives :Hydroxy derivatives in which —OH is directly attached to sp C (Alcoholic compounds).3(II)Aromatic hydroxy derivatives :Hydroxy derivatives in which —OH is directly attached to sp C or benzene ring (Phenolic compounds).2 Aliphatic hydroxy derivatives :( a )Classification according to number of —OH groups :(i)Monohydric[one –OH]CH CH —OH32(ii)Dihydric[two –OH]CH 2CH 2OHOH(iiii)Trihydric[three –OH]CH CH CH 2OHOH OH2(iv)Polyhydric[n –OH]CH -------------CHCH 2OHOH2OH( b )Classification according to nature of carbon :(i)p or 1° – alcoholCH CH – OH32(ii)s or 2° – alcohol(CH ) CH – OH3 2(i)t or 3° – alcohol(CH ) C – OH3 3Structure of alcohol :Alcohols are bent molecules. The carbon atom (linked with: :O sp 3sp 31s sp 3HC3H 1ssp 3108.5°Structure of CHOH3'O' atom of –OH group) is sp hybridised. The central 'O'3atom is also in sp state of hybridisation. The bond angle is3108.5 . In sp hybridisation of O - 2s ,2p0 32x2 2p 2py1z1orbitals hybridised to form sp orbitals3  O2s 2p 2p 2pxyzsp hybridisation3In these four orbitals two containing one electronNon - bonding e pair—  bond bond O atomsp 3+ .× .S108.5° C atom× .S× .S× .SH HHhybridised orbitals sp3 H atomeach and two containing two electrons each.Orbitals containing two electrons do not take partin bonding. Other two half filled orbitals form bond with s-orbitals of H -atom and hybridisedorbital of C-atom (O—C).Due to lone pair effect the bond angle oftetrahedral oxygen atom is lesser than normaltetrahedral structure (109 28').0ALCOHOL

MONOHYDRIC ALCOHOLGeneral methods of preparation :( a )From alkanes (By oxidation) :(CH ) C—H 3 34 H /KMnO (CH ) C—OH3 3( b )From alkenes :( i )By hydration :CH —CH3CH22HH OCH CH CH 3OH3(ii)By hydroboration oxidation :CH —CH3CH2322BHH OHOCH 2CH 3OHCH 2 (1° alcohol)(iii)By oxymercuration demercuration :CH —CH3CH 2224,(i) Hg(OAc) H O(ii) NaBH ,HOCH CH CH 3OH3( c )From alkyl halides (By hydrolysis) :CH —CH —Cl322Aq. KOHor Moist Ag OCH CH —OH32( d )From carbonyl compounds (By reduction) :>COReducing agent>C H—OHReducing agents may be,LiAlH /H NaBH /H4 4Na + EtOH [Bouveault-blanc Reduction]NaH [Darzen reduction]Ni/H2R—CHO4 LiAlHH R—CH —OH2C R RO4 NaBHH CH ROHRC CH CH 3O34 LiAlHH  ?Mechanism :H C CH CH 33C CH CH 3HO3OLiAlH4H C CH CH 3HOH3OLiAlH4D NaBD4H ODHOHD

CH —CH3CH—CHO4 LiAlHH CH —CH3CH—CH —OH2CrotonaldehydePh—CHCH—CHO4/ OH–LiAlHH Ph—CH —CH —CH —OH222Cinnamaldehyde( e )From ethers :R — O — R24 dil.H SOR—OH + R—OHCH —O—CH CH 32324 dil.H SOCH —OH + CH CH —OH332( f )From acid and derivatives (By reduction) :R—COOH4 LiAlHH R—CH —OH + H O22C Cl RO4 LiAlHH R—CH —OH + HCl2C OR RO4 LiAlHH R—CH —OH + R—OH2C O C OR ROO4 LiAlHH R—CH —OH + R—CH —OH22C NH RO24 LiAlHH R—CH —NH +H O222( g )From esters (By hydrolysis) :( i )By alkaline hydrolysis :C OR RONaOHC ONa + R OH RO(ii)By acidic hydrolysis :C OR RO2HH O(excess)C OH + R OH ROC OCH CH 3O25183H OC OH + CHOH CH 3O2518This reaction is reversible reaction and it's order is 1 and it is also called Pseudo-Unimolecular reaction.( h )From p-amines :R—NH222NaNOHClor HNOR—OH + N + H O22CH CH —NH3222 HNOCH CH —OH + N + H O3222Mechanism :2232232NaNOHClCH CH — NH CH CH — N Cl232 CH CHNCl(Unstable)

CHCH32ClOHN OCHCH32OH [major]OH CHCH32ClCHCH32O N OCH 2CH 2Inter mediate is carbocation so rearrangement may be possible.Ex.CH CH CH —NH 32222 NaNOHCl ?Sol. Mechanism :CH CH CH —NH32222 NaNOHClCH CH CH —3222N Cl CH CH CH322CH CH CH 3OH3HO CH CH CH 33 H 23233HNOCH — NHCH — O — CHException :( i )From Grignard reagent :( i )p-alcohol :R—Mg—X + [O]R—O—MgX2H OR —O H[Same C-p-alcohol]C HR MgC H HROMg XOHO2X + HC H HROH [one C more p-alcohol]R MgCH 2ROMgXCH 2H O2X + CH2CH 2CH 2ROHCH 2[two C more p-alcohol]O(ii)s-alcohol :C HR MgC H RROMgXOH O2X + RC H RROH C ORR MgC R HO RX + HC R HROH OHO2MgX

(iii)t-alcohol :C RR MgC R RROMgXOH O2X + RC R RROH C ORR MgC R RO RX + RC R RROH OH O2MgXPhysical properties :(i)C to C are colourless liquids and high alcohols are solids.111(ii)Density of monohydric alcohol is less than H O.2(iii)Density  mol. wt. (for monohydric alcohol).(iv)Solubility : C to C and t-butyl alcohol is completely soluble in H O due to H–bonding.132solubility No. of side chainsc 1molecular weightOrder of solubility :C H OH49>C H OH511>C H OH613CH CH CH CH OH3222<CHCHCH OH32CH 3<C OH CH 3CH 3CH 3CHCHCH322OH<CH CH CH 3OH OH2<CH CH CH 2OH OH2OH[Number of —OH increases, H-bonding increases](v)Boiling points : B.P.  molecular weigntIf molecular wt. is same then 1B.P.branching Order of BP :C H OH49<C H OH511<C H OH613CH CH CH CH OH3222>CHCHCH OH32CH 3>C OH CH 3CH 3CH 3CHCHCH322OH<CH CH CH 3OH OH2<CH CH CH 2OH OH2OH[Number of OH increases, H-bonding increases]Ex.Boiling point of alcohol is more than corresponding ether. Why ?Sol. Reason : H-bonding in alcohol.H OR---------- H OR------------- H OR ------------- H OR ----------

Ex.Boiling point of alcohol is less than corresponding carboxylic acid. Why ?Sol. Reason : Dimer formation in carboxylic acid.RCOOHH OOCRChemical properties :Monohydric alcohol show following reactions(A)Reaction involving cleavage of OH(B)Reaction involving cleavage of COH(C)Reaction involving complete molecule of alcohol( A )Reaction involving cleavage of OH: Reactivity order (Acidic nature) isCH —OH3>CH CH —OH32>(CH ) CH—OH3 2>(CH ) C—OH3 3( i )Acidic nature :H O >2R —O H>CHCH>NH3(Acidic strength)Alcohols are less acidic than H O and neutral for litmus paper and gives H with active metals (Na, K)22R—OH + Na R—ONa + 12H 2R—OH + K R—OK + 12H 2(ii)Reaction with CS :2R—OH + NaR—ONa + 12H 2R—ONa + SCS ROCSNaSSodium alkyl xanthate (Used as floating agent)(iii)Alkylation:R —O H22 CH NR — O —C H — H2R —O HNaR—ONaR XR — O — R(Williamson synthesis)(i v)Acylation :ROH + ClCROROCRO(Acylation)ROH + ClCCH 3OROCCH 3O(Acetylation)OHCOOH2CH COClCOOHOCRO Salicylic acidAcetoxy benzoic acidAcetyl salicylic acidAspirin [Used as analgesic]

( v )Benzoylation : (Schotten Baumann's Reaction) :ROH + ClCPhOROCPhO(Benzoylation)(v i)Esterification : Conc. H SO is used as catalyst and dehydrating agent.24ROH + ROHCO24 conc. H SOROR + HO2COMechanism :H SO 24H + HSO +–4R—C—O—H + HR—C—O—H: :OOH+R—C—O—H+ ROHR—C—OHO OHOHHR'R—C—OH2R—C—OR'R—CR—COR'OOR'OR'OHOHOH–H+Note : This is a laboratory method to prepare ester.Example :CH 3OH + H OCH CO2524 conc. H SOCH 3OC H + HO252COExample :PhOH + H COOC H251824 conc. H SOPhOCH + HO252CO18Dry HCl can be used as dehydrating agent.Example :CH 3OH + H OCH CO25Dry HCl.CH 3OC H + HO252CO(i)Reactivity for esterification 1Steric hinderence.(ii)Reactivity of R – OH [If acid is same] : CH – OH > 1° > 2° > 3° alcohol3(iii)Reactivity of RCOOH [If alcohol is same] :H COHO > CH 3OH CO > CH 3CH CCH O3OH > CH 3C CCH O3CH 3OH

(vii)Reaction with CHCH :CHCH + 2CH —OH33BF / HgOCHCH3OCH3OCH3MethylalCH CH + 2CH CH — OH323BF / HgOCHCH3OC H25OC H25 Ethylal(viii) Reaction with carbonyl compounds :R—CHO + 2R—OHH CH RORORAcetalRR + 2R OH COH CORORRR KetalCH CHO + 2CH —OH 33H CHCH3OCH3OCH3 Methylal(ix)Reaction with Grignard reagent :R—Mg—X + H—OR H H + Mg RXOR( x )Reaction with Ketene : Ketene is used as acetylating agent.CH2CO + R—OH CH 2OROH CCH 3ORO CCH2CO + C H —OH 25CH 2OC H25OH CCH 3OCH25O CEthylacetate(xi)Reaction with isocyanic acid : Ethyl urethane is used in preparation of ureaNHC O + H—OC H 25NH COC H25OHNH 2OCH25O CEthyl urethane(xii)Reaction with oxirane :ROHOROH + CH2CH 2OCH 2CH 2H +( B )Reaction involving cleavage of OH C: Reactivity order or basic nature isCH —OH3<CH CH —OH32<(CH ) CH—OH3 2<(CH ) C—OH3 3

( i )Reaction with halogen acid :R—CH —OH + HCl 22 ZnCl R—CH —Cl2 + H O2R CH—OH + HCl 22 ZnCl  R CH—Cl + H O222 alcohol 0Reactivity of the acids is HI > HBr > HCl > HF(ii)Reaction with inorganic acids :O OH + H O N ROO + HO2O NOR Nitric acidAlkyl nitrateR—OH + HHSO4R—HSO + H O42Alkyl hydrogen sulphate(iii)Reaction with phosphorous halides :3R—OH + PCl33RCl + H PO33R—OH + PCl5 R—Cl + POCl + HCl3(i v)Reaction with thionyl chloride (SOCl ) :2R—OH + SOCl 2PyridineR—Cl + SO + HCl2 (gas)( v )Reaction with NH : Alumina (Al O ) is used as dehydrating agent.323OH + HNH2R23 Al O250 CR—NH + H O22(v i)Reaction with halogens : Oxidation and chlorination takes place simultaneously.CH CH OH + Cl (dry)322CH CHO + 2HCl (Oxidation)3CH CHO + 3Cl32CCl CHO + 3HCl (chlorination)3chloral( C )Reaction involving complete molecule of alcohol :( i )Dehydration : Removal of H O by two type2(a)Intermolecularly removal of H O [form ether]2(b)Intramolecularly removal of H O [form alkene]2(C H) SO25 24100°C140°C170°CC H OH + HSO25 24(conc.)0°CC HHSO254C H25O C H (Williomson's synthesis)25CH 2CH (Elimination)2250°C350°CC H OH +Al O25 23(Alumina)C H25O C H25CH 2CH 2Ease of dehydration follow the order : 3° ROH > 2° ROH > 1° ROH > CH OH3

(ii)Catalytic Dehydrogenation : This reaction is useful in distinction of 1°, 2° and 3° alcohols.CH CH OH32Cu300 CCH CHO + H32(p- alcohol )(Acetaldehyde)CH 3CH CHOH3Cu300 CCH 3CH + H32CO(s- alcohol) (acetone)CH 3C OHCH 3CH 3(t. alcohol)Cu300 CCH 3C CH + HO [dehydration]CH 322(Iso - butylene)(iii)Oxidation : This reaction is useful in distinction of 1°, 2° and 3° alcohols.R—CH —OH24722HKMnO orH / K Cr O RCHO[O]Room temp.RCOOH(p-alcohol)(same carbon acid)RR COR CH R'OH(s-alcochol)(same carbon)H /KMnO or4H /K Cr O 272[O]high temp.No reactionAcids (less carbon)Room temp.R C ROH(t-alcohol)[O]high temp.No reactionAcids (less carbon)Room temp.RCHCH32CH CHOH3[O]high temp.O CHCH32C CH3[O]CH COOH + CH COOH33Carbonyl group goes with smaller alkyl group(i v)Reaction with phosporous pentasulphide :R—OH + P S2 5R — S H+P O25Thio alcohol( v )Reaction with salts :CuSO. 2CHOH43CaCl2MgCl2CHOH3CuSO4CaCl . 4CHOH23MgCl . 6CHOH23(v i)Distinction between 1°, 2° and 3° alcohols :( a )Lucas test : A mixture of HCl(conc.) and anhydrous ZnCl is called Lucas reagent.2p-alcohol2 ZnClHClNo turbidity at room temp. [On heating within 30 minutes.]s-alcohol2 ZnClHClTurbidity appears within 5 minutes.t-alcohol2 ZnClHClTurbidity appears within 1 minute.

( b )Victor - Meyer test : This is colour test for alcohol (pri. sec. & tert.) .p-alcoholRed colours-alcoholBlue colourt-alcoholNo colourR—CH —OH [1°]2R CH—OH [2°]2R C—OH [3°]3 P + I2 P + I2 P + I2R—CH —I2R CH—I2R C—I3AgNO2AgNO2AgNO2RCH —NO22R CH—NO22R C—NO32 HNO2 HNO2 HNO2R—C—NO2R C—NO22No reactionN OHNNaOHNaOHNaOHSoluble (Red)Insoluble (Blue)Colourless (White)(vii) Dichromate test :1° Alcohol7226HK Cr Oorange [Cr] Acid + Cr+3 [green]2° Alcohol7226HK Cr Oorange [Cr]Ketone + Cr+3[green]3° Alcohol7226HK Cr Oorange [Cr] No oxidation, No green(viii) Test of alcholic group :R —O HNa R—ONa + 12H 2 [effervesence of H ]2R —O H5 PClR—Cl + POCl + HCl33 NHNH Cl4 [White fumes]R —O H Cerric ammonium nitrateRed colour(ix)Distinction between CH3 – OH and C H OH25CH OH3CH CH OH32B.P.65°C78°CI + NaOH2No pptYellow ppt of CHI3Cu/300°CSmell of formalin [HCHO]No smellSalicylic acidSmell of oil of wintergreenNo smell

OHCOOHOHCOOH3OHCOOPhO C CHCOOH3OMethyl salicylate(Oil of wintergreen)Phenyl salicylateSalol (Internal antiseptic)Aspirin(Analgesic)CH OH3Ph—OHCH COCl3Additional reactions :(a) Oxidation by HIO [per iodic acid] :4CH 2CH 2OHOH4 HIOCH 2OH + HO CHOHOH 222H O HCHO + HCHOCH 2CH CHOHOH OH2(Glycerol)4 HIOHOCH+HO CH OH + HO CH2OHOH2OH23H OHCHO+HCOOH+HCHOCondition for oxidation by HIO :4 At least 2 —OH or 2 >C=O or 1 —OH and 1 >C=O should be at adjacent carbons.Example :CHCH C CHOHOH OHCH 33CH 3CHCHO + HCOOH + CH33C CH3O2HIO4Example :CCH CH CO OH2CH 3OCHCOOH + CHO CH32CHOHHIO4Example :CHOOOOH HO CH22HIO4CHOOOH HO CH2C OH O(HCO)23–H O2CHOHO CH2CHOCOOH+HO + CO22OHOH+ HO( b )Pinacole - Pinacolone Rearrangement :C CH 3CH CH3OH OHCH 3C324 conc. H SOC CH 3O CHCH 3CCH 33PinacolePinacolone

Mechanism :C CH 3CH CH3OH OHCH 3C3H C CH 3OH OHCH 3CCH 32CH 3–HO2C CH 3OHCH 3C CH 3C CH 3:O HCH 3C CH 3CH 3..C C CH 3OHCHCH 33CH 3–HC CH 3O CHCH 3C3CH 3CH 3(Complete octet more stable) AROMATIC HYDROXY DERIVATIVESPhenolic compounds :Compounds in which —OH group is directly attached to sp c [Benzene ring]2OHCH 3OHOHCOOHPhenolo-cresolSalicylic acidOHOHOHOHOHOHcatecholresorcinolquinolAll phenolic compounds give characteristic colour with neutral FeCl .3Ph—OH3 neutral FeClViolet colourCH CH —OH323 neutral FeClNo colourPHENOL (C H OH)65Phenol is also known as carbolic acid or Benzenol or hydroxy benzene.In phenol —OH group is attached withsp hybridised carbon.It was discovered by Runge in the middle oil fraction of coaltar distillation and named it2carbolic acid (carbo = coal; oleum = oil) .It is also present in traces in human urine.General Methods of preparation :( 1 )From benzene sulphonic acid :When sodium salt of benzene sulphonic acid is fused with NaOH phenol is obtained.C H SO Na + NaOH 653C H OH + Na SO6523( 2 )From benzene diazonium chloride :When benzene diazonium chloride solution is warmed, phenol is obtained with evolution of nitrogen.NCl22(Steam distilled) H OOH + N + HCl2

( 3 )By distilling a phenolic acid with sodalime (decarboxylation):OHCOOHNaOH CaOOH + Na CO23Salicylic acid( 4 )From Grignard reagent : (The Grignard reagent on reaction with oxygen and subsequent hydrolysis by acidyields phenol)C H MgBr 65[O] C H OMgBr 652H O C H OH + 65MgBrOH( 5 )From benzene : + [O]25 V O300 COH( 6 )From chloro benzene :Ph—ClAq. NaOHNo NSR at normal conditionStable by resonanceR—ClAq. NaOHR —O H[NSR]Ph—ClAq. NaOH300 CPh—ONaOrder of NSR :ClClNO 2ClNO 2ClNO 2NO 2NO 2NO 2max. –I, –Mmin. edmin. ESRmax. NSRAq. NaOH25°C300°CAq. NaOHOHOHNO 2NO 2NO 2<<<2, 4, 6–Trinitrophenol (Picric acid)( 7 )Industrial preparation of phenol:Phenol can be prepared commercially by :(a)Middle oil fraction of coaltar distillation(b)Cumene(c)Raschig process(d)Dow's process

( a )Middle oil fraction of coaltar:CoaltarFractionaldistillationMiddle oil (170-230°)CoalNaphthaleneliquid(Solid crystals separate out)C HONa65NaOH (dil.)C HOH + Na CO6523CO /H O or sulphuric acid22(Phenol, cresols, Naphthalene)( b )From cumene (Isopropyl benzene) : Cumene is oxidised with oxygen into cumene hydroperoxide inpresence of a catalyst. This is decomposed by dil. H SO into phenol and acetone.24CH CH 3CH 3Cumene2 O130 CC(CH)3 2O OHCumene hydroperoxide242H SO ,H OH /100 C OHC CH + CH3O3( c )Raschig process : Chlorobenzene is formed by the interaction of benzene, HCl and air at 300 C ino presence of catalyst CuCl + FeCl . It is hydrolysed by superheated steam at 425 C to form phenol and23o HCl.C H + HCl + 6612O 2230CuClFeCl300 CC H Cl + H O652C H Cl + H O6520425 CC H OH + HCl65(super heated steam)( d )Dow process : This process involves alkaline hydrolysis of chloro benzene-(large quantities of phenolformed).C H Cl + NaOH650Cu — Fe300 COH+ NaClPhysical properties :(i)Phenol is a colourless, hygroscopic crystalline solid.(ii)It attains pink colour on exposure to air and light. (slow oxidation)C H OH--------65OO----------- HOC H65Phenoquinone(pink colour)(iii)It is poisonous in nature but acts as antiseptic and disinfectant.(iv)Phenol is slightly soluble in water , readily soluble in organic solvents.(v)Solublity of phenol in water is much lower than alcohols because of larger hydrocarbon part in themolecule.(vi)Due to intermolecular H-Bonding, phenol has relatively high boiling point than the correspondinghydrocarbons, aryl halides etc. but intermolecular H-bonding in o–derivatives is used in the preparationof dyes, drugs, bakelite and it's melting point (MP) is 43° C and boiling point (BP) is 182° C .

Chemical Properties :( A )Reactions due to –OH group :Acidic Nature : Phenol is a weak acid. The acidic nature of phenol due to formation of stable phenoxideion in solution. The phenoxide ion is stable due to resonance. The negative charge is spread through outthe benzene ring which is stabilising factor in the phenoxide ion. Electron withdrawing groups(–NO , –Cl) increase the acidity of phenol while electron releasing groups (–CH etc.) decrease the23acidity of phenol.65C H OH653C H OH O Phenol is stronger acid than alcohols but weaker than the carboxylic acids and even carbonic acidThe acidic nature of phenol is observed in the following:(i)Phenol changes blue litmas to red.(ii)Highly electro positive metals react with phenol.2C H OH + 2Na652C H ONa + H652(iii)Phenol reacts with strong alkalies to form phenoxides.65C H OH NaOH652C H O N a H O(iv)However phenol does not decompose Na CO or NaHCO because phenol is weaker than carbonic acid.233C H OH + Na CO or NaHCO65233No reactionPh—OH+NaHCO 3Ph—ONa+H CO23Acid-IBase-IBase-IIAcid-IIAcid-I < Acid-IIBase-I < Base-IIReaction in reverse direction.(v)Phenol does not react with NaHCO .3C OH CH 3O+NaHCO3C ONa CH 3O+H CO [H O + CO2322 ]Acid-IBase-IBase-IIAcid-IIAcid-I > Acid-IIBase-I > Base-IIReaction in forward direction.(vi)Acetic acid reacts with NaHCO and gives effervesence of CO .32Reaction with PCl : Phenol reacts with PCl to form chloro benzene. The yield of chlorobenzene is5 5poor and mainly triphenyl phosphate is formed.C H OH + PCl655C H Cl + POCl + HCl6533C H OH + POCl653(C H ) PO + 3HCl65 34Reaction with Zn dust: When phenol is distilled with zinc dust benzene is obtained.C H OH + Zn65C H + ZnO66Ex.OH CH 2Zn?Sol. No reaction

Ex.CH 3OHZn?Sol.CH 3Ex.CH 3CH 3Zn ?Sol. No reactionEx.COOHOHZn ?Sol.COOHReaction with NH ( Bucherer reaction): Phenol reacts with NH in presence of anhydrous ZnCl to332form aniline.C H OH + NH65324 233Anhydrous ZnCl or (NH ) SO / NH 150 C300 CC H NH + H O6522Reaction with FeCl : Phenol gives violet colouration with FeCl solution (neutral) due to formation of a33complex.C H OH + FeCl653Voilet colourThis reaction is used to differentiate phenol from alcohols.Acetylation (Schotten-Baumann reaction) : Phenol reacts with acid chlorides or acid anhydrides inalkali solution to form phenyl esters.C H OH + ClCOCH653NaOHHClCHO—C CH65O3C HOH + Cl65OC CH65NaOHHClCHO65OC—CH65Ether formation (Alkylation) : Phenol reacts with alkyl halides in alkali solution to form phenyl ethers.(Williamson's synthesis)C H OH + NaOH65alkali solutionC H ONa 65RXNaX C H OR65Sodium phenoxideC H OH + CH N6522C H OCH + N 6532Reaction with P S :2 5 5C H OH + P S652 55C H SH + P O6525

( B )Reaction of Benzene Ring : The —OH group is ortho and para directing. It activates the benzene nucleus.Halogenation : Phenol reacts with bromine in CCl to form mixture of o–and p–bromo phenol.4OH+ Br2324low.temp.CHCl or CS or CHClOHBr+OHBrPhenol reacts with bromine water to form a white ppt. of 2,4,6 tribromo phenol.OH + 3Br22H OOHBrBrBr + 3HBrNitration : Phenol reacts with dil. HNO at 0°–10° C to form o- and p- nitro phenols.3OH3 dil.HNO0 10 COHNO 2(40%) +OHNO (10%)2 When phenol is treated with nitrating mixture to form 2,4,6- trinitro phenol (picric acid)OH234Conc.HNOConc.H SOOHNO 2NO 2NO 2[2, 4, 6–Trinitrophenol (Picric acid)]Sulphonation: Phenol reacts with fuming H SO to form o–and p–hydydroxy benzene sulphonic acid24at different temperatures.OH+ conc. HSO2425°C100°COHSOH3OHSOH3Friedel-Craft's reaction : Phenol when treated with methyl chloride in presence of anhydrous AlCl3p-cresol is main product.OH+ CH Cl33 Anhydrous AlClOHCH 3OHCH 3+o-cresolp-cresol

OH + CH COCl33 Anhydrous AlClOHCOCH3OHCOCH3+o – and p – hydroxy acetophenoneGattermann aldehyde synthesis : When phenol is treated with liquid HCN and HCl gas in presenceof anhydrous AlCl yields mainly p- hydroxy benzaldehyde (formylation)3HCl + HCN3 AlClHNCHClOH + HNCHCl 3 AlClHClOHCH NH23H ONHOHCHORiemer-Tiemann reaction : Phenol on refluxing with chloroform and NaOH (aqueous) followed byacid hydrolysis yields o–hydroxy benzaldehyde. When CCl is used salicylic acid is formed.4OHCHCl360°C NaOH (aq.)CCl460°C NaOH (aq.)CHCl2OHNaOHCHOONa H +HO2CHOOHCCl3OHNaOHCOONaONa H +HO2COOHOHSalicylaldehydeSalicylic acidMechanism : CCl is neutral attacking electrophile (formed by 2 elimination reaction)CHCl3 KOH:CCl2O H HOO OO CCl2HClCl C OH–HO2CHOO OHOH CHH OH O ClCl CH:–H O2Kolbe 's Schmidt reaction : This involves the reaction of C H ONa with CO at 140 C followed by6520 acid hydrolysis salicylic acid is formed followed.O NaOHCOONa+ CO2140° C6 atm. pressureOCOONaRearrangement H +H O2OHCOOHSodium phenyl carbonateSodium salicylateSalicylic acid

Hydrogenation: Phenol when hydrogenated in presence of Ni at 150-200 C forms cyclohexanol.0OH+ 3H2Ni150 – 200° COHCyclohexanol. (C H OH)611(used as a good solvent)Fries rearrangement reaction :C H OH + CH COCl 6533 Anhydrous AlCl C H OCOCH65360°COHOHCOCH3anhydrous AlCl3C HOCOCH653Phenyl ester (acetate)COCH3Duff 's reaction: This method gives only the o-compound which is hindered by the presence of a –Igroup in the ring.OHOHCH NCH+(CH) N2 64GlycerolBoric acid HO2OHCHOacidified with HSOand steam distilled (15–20°C)243Hexamethylene tetramineCoupling reactions: Phenol couples with benzene diazonium chloride in presence of an alkalinesolution to form a dye (p- hydroxy azobenzene) red only.NCl +2OHNaOH–HClN NOHp–hydroxy azobenzene (Orange dye or Red dye)Phenol couples with phthalic anhydride in presence of conc. H SO to form a dye (phenolphthalien)24used as an indicator.O C C O HOHOHHOH SO24–H O2O C COHOHOPhenol (2 molecules)Phenolphthalien (Colourless in acidic medium and pink in alkaline medium)+Lederer Manasse (Condensation with formaldehyde) : Phenol condenses with HCHO (excess) inpresence of NaOH or weak acid (H ) to form a polymer known as bakelite (aresin).+

OHPolymer bakelite (Phenol formaldehyde resin)OHOHCHOH2+ HCHONaOHOHPolymerisationcondensation with HCHOCHOH(40%)2+(20%)CH 2CH 2CH 2HOOHCH 2OHCH 2CH 2Leibermann's nitroso reaction : When phenol is reacted with NaNO and conc. H SO it gives a224deep green or blue colour which changes to red on dilution with water. When made alkaline with NaOHoriginal green or blue colour is restrored.This reaction is used as a test of phenol.2NaNO + H SO2242HNO + Na SO224OHOHNOHON OHC H OH6 5H SO24Green phenolor blue colour H O2RedIndophenol ionNaOHBlue Sodium (original or blue is restored)Salt green colour HONOReaction with acetone: (Condensation with acetone)OHHOHHC CH CH 3O3con. HCl–HO2OHOHC CH CH 33Bis - Phenol-Ap-p'– Isopropylidene diphenolOxidation:OH(Phenol)CrO Cl2 2(O)Air [O]H/KMnO4K S O /KOH2 28OO + HO2HOOH(Elb's persulphate reaction)1, 4 – Dihydroxy benzeneHHOHOHCOOHCOOHp-Benzo quionone (Red)Meso tartaric acid(Quinol)

Test of Phenol :(i)Phenol turns blue litmus to red.(ii)Aqeous solution of phenol gives a violet colour with a drop of ferric chloride.(iii)Phenol gives Lieber mann 's nitroso test.Phenol in conc. H SO 242 NaNOexcess of water Red colour NaOH excess Blue colour(iv)Aqeous solution of phenol gives a white ppt. of 2,4,6 tribromophenol with bromine water.(v)Phenol combines with phthalic anhydride in presence of conc. H SO to form phenolphthalein which24gives pink colour with alkali.(vi)With ammonia and sodium hypochlorite , phenol gives blue colour.Differences between phenol and alcohol (C H OH) :25(i)Phenol is more acidic than aliphatic alcohol due to resonance in phenoxide ion.(ii)Phenol gives violet colour with FeCl while aliphatic alcohol does not give.3(iii)Phenol gives triphenyl phosphate with PCl while aliphatic alcohol gives alkyl chloride.5(iv)Phenol has phenolic odour whereas alcohol has pleasent odour.(v)Phenol on oxidation gives quinone while alcohol gives aldehyde or ketone and acids.Uses of Phenol : Phenol is used :(a)As an antiseptic in soaps and lotions. \"Dettol\" (2,4-Dichloro-3,5-dimethyl phenol)(b)In manufacture of azodyes, phenolphthalein , picric acid (explosive), cyclohexanol (Solvent for rubber),plastics (bakelite) etc.(c)In manufacture of drugs like aspirin salol, phenacetin etc.(d)As preservative for ink.

ETHERR—O—R (Dialkyl ether), alkoxy alkane. It's General formula is C Hn2n + 2O.CH —O—CH CH (Methoxy ethane) or ethyl methyl ether or 2–oxa butane323Ether is monoalkyl derivative of R–OH and dialkyl derivative of H O2R — O HHR R — O — R2H2R  H—O—HClassification : They may be classified as :(a)Simple or symmetrical ether. e.g. R–O–R(b)Mixed or unsymmetrical ether e.g. R–O–R'Structure :: : sp hybridizedO3RR  bondbond 110°The molecule of ether is bent due to lone pair of electron on oxygenatom- bond electron repulsion. The bond angle is 110 . It is greater0than that of water 105 due to the repulsion between bulky alkyl groups.0Due to bent structure, it posses dipole moment and hence are polarmolecules.General Methods of Preparation :( A )From alkyl halides :( i )By Williamson's synthesis :R—X + Na—O—RR—O—R + NaX [2N S Reaction]Example : CH —I + C H O Na325–+CH —CH O—CH + NaI323Mechanism : [2N S Reaction]C H O+ Na25C H ONa25HHHHC H —O—CH2+ I53C H O25C H O------ C ----- I25C— IHHSlowFastNa + INaIExample :CH 3CCl + CHONa3CH 3CH 3HC C3CH 3CH 2Example :CH 3CONa + CH3CH 3CH 3CH 2ClCH 3CCH 3CH 3O CH2CH 3Example : CH2CH—Cl + CH CH —ONa32No reaction[Stable by Resonance]

(ii)Reaction with Dry Ag O :22RX + Ag O2R—O—R + 2AgXExample : 2CH —CH —Cl + Ag O 322CH CH OCH CH + 2AgCl3223( B )From R–OH:( i )By dehydration :R —O H24 Con. H SO ?250°C350°CCHCH32OCHCH23CH 2CH 2Al O23CH 3CH 2OHconc. HSO24140°C170°CCHCH32OCHCH23CH 2CH 2(Willomson's synthesis)(Elimination)(ii)Reaction with CH N (diazomethane) :22R—OH + CH —N223 BF R—O—CH —H + N22Physical Properties :(i)CH OCH , CH OCH CH are gases and higher are volatile liquids.33323(ii)Ether are less polar [ =1.18D].(iii)Ethers are less soluble in H O.2(iv)Ethers have less BP then corresponding alcohol.Ex.Ethers are less soluble in H O . Why ?2Sol. Reason : Due to less polar, it forms weaker H–Bonding with H O.2Ex.Ethers have less BP then corresponding alcohol. Why ?Sol. Reason : No H–Bonding in ether molecules.Chemical properties :Ethers are less polar so less reactive and do not react with active metals [Na,K], cold dil. acid, oxidising andreducing agent.Reason : They do not have any active functional group.1 .Basic nature : Due to presence of .p on oxygen atom ether behave as lewis baseEthers react with cold conc. acid and form oxonium ionExample : cold ; conc. HClC HOCH2525C H25O C H ClH25....(diethyl oxonium chloride)Example : cold ; conc.C H25O C H HSOH25....4C H25O C H25HSO24(diethyl oxonium hydrogen sulphate)Ether form dative bond with Lewis acids like BF , AlCl , RMgX etc.33

Example : RRO ....R Mg XRR O ....O ..:RRBF FF[Ether is used as solvent] for Grignard reagent.2 .Halogenation :CHCH32O CHCH23Cl /dark210 Cl light2CHCH O CH CH3Cl3Cl'–Dichloro diethyl etherC Cl25O C Cl + 10 HCl25Perchlorodiethyl ether3 .Formation of peroxides : Ether add up atmospheric oxygen or ozonised oxygen. It is explained by Freeradical mechanism as intermediates is free radical.C H —O—C H25252O (nonpolar)Long contactCHCH32O CHCH3O O H(Non polar)sunlight or UVC HOCH + O2525........C HOCH or (CH) O2525 25 2....OO ....: :CH CH —O—CH —Ph 3222 Olong contactCH —CH —O—32CH —Ph 2 OCH 3O CH PhO O HCH 2stable by resonancePeroxides are unstable and explosives.43FeSO / KCNS+ 2+ 3CNSTest for peroxides ether (peroxide) Red colourether (Peroxides) + FeFeFe(CNS)(Red) 4 .Reaction with hot dil. H SO24 :R — O — R24hot dilH SO2R—OH5 .Reaction with hot conc. H SO : R — O — R2424 hot conc. H SO2RHSO4CH 3O CH2cold dil.cold conc.hot dil.hot conc.H SO24CH 2CH 3No ReactionOxonium saltEthyl alcoholEthyl hydrogen sulphate6 .Reaction with PCl5 :ROR + PCl5heat2RCl + POCl37 .Reaction with BCl :33ROR + BCl33RCl + (RO) B3

8 .Reaction with RCOCl :ROR + RCOCl 32AlClZnCl heatRCOOR +RCl9 .Reaction with CO :ROR + CO3BF / HgO 500 atm150 CRCOOR1 0 .Reaction with C H Na : 25CHCH22O CHCH + CH2225HHStrongerbase CH CH OH + CH322CH +C H2261 1 .Dehydration :CHCH32O CHCH 23Al O232CH2CH + HO2 21 2 .Reduction :CH CH OCH CH3223Red P HIheat2CH CH331 3 .Oxidation :CH CH —O—CH CH3223227 H / K Cr O 2CH CH OH32[O]2CH CHO 3[O] 2CH COOH31 4 .Combustion :C H OC H + 6O252524CO + 5H O22(explosive mixture)1 5 .Reaction with HX :Reactivity of HXHI > HBr > HClReaction with cold conc. HX :Ethers forms oxonium salt with cold and conc. HCl (less reactive)Cold conc. HI and HBr (more reactive) break C–O bond.Ex.CH 3CO CHCH 3CH 32CH 3Cold and conc.HI ?Sol. MechanismCH 3CO CHCHCH 3CH 323....H +CH 3CO CHCHCH H3CH 323CH 3CH 3CH 3(Oxonium ion)ICI + CHCHOH32CH 3CH 3CH 3If oxonium ion gives more stable carbocation [2 Ph CH ,CH2CH—C H , (CH )23 3C ] then SN reaction occurs.1If oxonium ion gives less stable carbocation [Ph , CH2C H, CH3C H ] then SN reaction occurs,22and X attacks at less hindered carbon.Ex.CH CH —O—CH Ph 322Cold con.HI CH CH —OH + PhCH —I, write mechanism of given reaction.322Sol. Mechanism :CHCHOCHPh322....H CHCH32O CHPh2H CH CH OH + Ph CH32I2 PhCH I + CH CH –OH232

Ex.CH CH —O—CH 323anhy.HI?Sol.CHCH32OH....HICH 3CHCH32O CH 3ICHI + CHCHOH332Oxonium ion gives less stable carbocationSN reaction I2attacks at less hinderd carbon.Ex.CH —CH —O—Ph 32(aq.)HBr ?Sol. Mechanism : CH 3OH.... H +PhCH 3O PhCH 2CH 2 BrCHCHBr + PhOH32CH 3CHCH32OCH CH3I cold and conc. HIS N 1CHCHOH + I32CH CH3CH 3CHCH32CH CH3CH 3I + HO2°1°S N 2If excess of HI is used then two moles of alkyl hallides are formed.CH CH —O—CH Ph322HI CH CH OH+PhCH I 322322HICH CH — IPhCH — I( B )Reaction with hot and conc. HX :CH CH —O—CH 323hot and conc HI CH CH —I + CH —I323Ex.C H —O—C H 2525hot and conc. HBr? + ?Sol. C H —Br + C H — Br2525 Uses of ether :(i)General anaesthetics agent.(ii)Refrigerant a mixture of ether and dry ice gives temperature as low 110°C.(iii)Solvent for oil, fats, resins, Grignard reagent.(iv)For providing inert & moist free medium to organic reaction example : Wurtz reactions.(v)In perfumery.(vi)Di-isopropyl ether Petrol as an antiknock comp.(vii)Mixture of alcohol and ether is used as a substitute of petrol. Trade name \"Natalite\"(viii)Halothane (CF CHClBr) used as an anaesthetic because it produces unconsciousness without affecting3lung and heat.Preparation of Epoxides :(i)Epoxidation of alkenes by reaction with peroxy acids(ii)Base-promoted ring closure of vicinal halohydrins(iii)Epoxidation of alkenes by reaction with peroxy acids

Epoxidation of alkenes by reaction with peroxy acids :C—CC=CO+ R–C–OHO+ R–C–OOHOEpoxidePeroxy acidExample :(a)CH–CH(CH) CH + CH–C–OH22 933OCH–C–COOH3OOCH= CH–CH) –CH+2(2 93 (b) + CH–C–OOH3O+CH–C–OH3OO(c)Epoxidation is a stereospecific syn addition :C = CC H65HC H65H+CH–C–OOH3OO HC H65HC H65+ CH–C–OH3O(E) -1,2-diphenyl ethenetrans -2,3-diphenyl oxiraneMechanism :CH–C3OOO HCCCH–C3OOOCCCH–C3OOH +O––C––CEpoxidetransition stateBase-promoted ring closure of vicinal halohydrins :R C = CR 2222xH oR C––CR22HO XR C–––CR22OHO –Vicinal halohydrinEpoxideMechanism :Step IRRC––CC––CR XXRRO ..O ......H HO – ....RR+ HO—H R..–Step IIRRC––CC––CXRRO ..O....RR....–RR + X–........

Example :(i)OHOHHBrNaOHOHHtrans-2-bromocyclohexanol1, 2-epoxycyclohexane(ii)HC3HC3HHBr /HO 22Anti additioninversion of BrOHHHHC3HC3HC3HC3OHHcis-2-butaneconfigurationcis-2, 3-epoxybutane(iii)HC3HHBr /HO 22Anti additioninversion of BrOHHHCH 3HC3CH 3HC3OHHtrans-2-butaneconfigurationtrans-2, 3-epoxybutaneCH 3Reaction of Epoxides :With Grignard reagent :RMgX + HC––CH22O3(1) diethylether(2) H ORCH CH OH (primary alcohol)22CHMgCl2+HC––CH22OBenzyl magnesiumchlorideEthylene oxide3-phenyl-1-propanol CHCHCHOH222(i) diethylether(ii) H O3+Nucleophilic ring opening reactions of epoxides :Y: + R C––––CR–22OR C–––CR22YO......2H OR C–––CR22YOH......HC–––CH22O223 KS CH CH CHethanol water, 0 CCH ––CH CH ––CH SCH CH OH3222222-(butylthio) ethanol

Note :Nucleophilic ring opening reactions of epoxides is the characteristic feature of 2N Sreaction.(i)HHO2332NaOCH CHCH CH OHOCHCH23HOH HHOHHC3HC3NH/HO32CH 3CH 3HHOHHN2(ii)C––––CHHC3CH 3OCH 333NaOCHCH OHCH––CH––C––CH33CHO3CH 3OHNucleophilic ring opening of epoxides :C H MgBr + 65HC–––CHCH23O31, diethyl ether2, H OCHCHCH––CH6523OHOORR–Y:Y.... –RO Y.... ..ROHY ––....epoxidetransition statealkoxide-substituted alcoholCH–––CH(CH) CH22 73O421. LiAlH2, H OCH––CH––(CH) CH32 73OH(i)HC–––CH22OHBr10 C BrCH CH OH22(ii)HC–––CH22O3224CH CH OHH SO , 25 C CH –CH OCH CH OH3222HC–––CH22O + H O 23H O HOCH CH OH22MechanismStep-1 :HC–––CH + H—O22O+HH :: :HC–––CH22+ HO:2:O+H..

Step-2 :HHC–––CH22O+HHO +....: :H—O+CH–CH–O–H22......HSlowStep-3 :HH—O+HO + : :CH–CH–O–H22......HHHO—H + HOCHCHOH22+..........Example :O HHHHOHOHHBr1,2-Epoxycyclohexanetrans -2-bromo cyclohexanolHC3HC–––COCH 3CH 3324CH OHH SOCH––CH––C––CH33OCH3CH 3HO2,2,3-trimethyl oxirane3-methoxy-3-methyl-2-butanol



Introduction :Organic Compounds having C O group are called carbonyl compounds and C O group is knownw nas carbonyl or oxo group. It's general formula is C H O (n = 1, 2, 3......) Carbonyl compounds aren2ngrouped into two categories.( a )Aldehydes : Aldehyde group is C HO (also known as formyl group). It is a monovalent group( b )Ketones : The carbonyl group ( C O) is a Ketonic group when its both the valencies are satisfiedby alkyl group. It is a bivalent group.Ketones are further classified as :(i)Simple or Symmetrical ketones : Having two similar alkyl groups. C O RR(ii)Mixed or unsymmetrical ketones : Having two different alkyl groups. C O RR'Example : (Ketones) : S ym me t ri ca lUnsymme trical C O CH 3CH 3 C O CHCH32CH 3(Acetone or Dimethyl ketone)(Ethyl methyl ketone)2–Propanone2–ButanoneSpecial Point : C OH, C X,O..O.. C NH,2O.. C OR,O..In all the compounds given above, lone pair of electrons and double bond are conjugate. C ZO .. so resonance occurs. These compounds have CO group still they are not carbonyl compoundsbecause carbonyl group takes parts in resonance with the lone pair of electrons.Structure :In C O compounds C-atom is sp hybridised which forms two bonds with C and H-atom respectively2and one bond with oxygen atom. The unhybridised atomic orbital of C-atom and the parallel 2p orbitalof oxygen atom give the  bond in C O group. C O CCsp 2 The C—C—O and H—C—O bond angles are of 120°.Due to electro-negativity difference in C & O atoms, the C O group is polar.. C O Hence aldehydes and Ketones posses dipole moment.ALDEHYDES AND KETONES

General Methods of Preparation :( A )For both Aldehydes and Ketones :( 1 )By Oxidation of Alcohols :( a )By K Cr O / H SO :22724Oxidation of primary alcohols gives aldehyde and oxidation of secondary alcohols gives Ketones.Here, (K Cr O / H SO ) is a strong oxidising agent.227242RCH OH22724[O]K Cr O / H SO (dil.)RCHO(Aldehyde) CH ROH R22724[O]K Cr O / H SO C RO R(Ketone)Aldehydes are quite susceptible to further oxidation to acids -RCH OH2[O] R—CHO[O]R—COOHThus oxidation of primary alcohols is made at the temperature much above the boiling point ofaldehyde and thus aldehydes are vapourised out and prevented from being oxidised. Note : Aldehydes can be prepared from 1° alcohol,secondary alcohols can be oxidized to ketones, by oxidationwith pyridinium chlorchromate (PCC) in CH Cl solvent, pyridinium dichromate (PDC) and with22 Jones reagent(CrO +H SO ) in acetone.324( b )Oppenaur Oxidation :The oxidation of secondary alcohols to ketones by heating them with specific reagent : [(CH ) CO] Al3 33(Aluminium-t-butoxide) in presence of acetone. Primary alcohols may also be oxidized to aldehydesif ketones is replaced by a better hydrogen acceptor, e.g. p-benzoquinone. The equilibrium can becontrolled by the amount of acetone, an excess of which favours the oxidation of the alcohol. CHOH RR + C O CH 3CH 33 33[(CH ) CO] Al C O + RR CH OH CH 3CH 32 Alcohol AcetoneO KetoneIsopropyl alcoholRCH OH + O2O 3 33[(CH ) CO] Al R—CHO + HO——OH1 Alcohol Quinone 0 Aldehyde Quinol Note :The reaction is the reverse of Meerwein-Ponndorf -verley reduction.( c )Mild Oxidising Agent :1 alcohols will get oxidised with CrO / Pyridine, collin's reagent Ag / O at 250 Co32oRCH OH + [O]2RCHO + H O2By this reaction, good yield of aldehyde is possible.( 2 )Dehydrogenation of alcohols :CH CH OH32Cu300 CCH CHO3(Acetaldehyde) CH3CHCH3OHCu300 CCH C CH3O3(Acetone)

CH C OH3 CH 3CH 3Cu300 CCH C + HO3 2CH 2CH 3(Isobutylene)( 3 )By Hydrolysis of gem dihalides :Terminal gem-dihalides on hydrolysis give aldehydes while the non-terminal dihalides give ketone. CHCH3ClClKOH(aq) CHCH3OHOH2H OCH CHO3Terminal gem-dihalide[unstable]AcetaldehydeCH C CH3 3ClClKOH(aq)CH C CH3 3OHOHunstable2H OCH C CH3 3OAcetone( 4 )By Oxidation of diols :With periodic acid (HIO ) & lead tetra acetate (CH COO) Pb vicinal diols gets oxidised to form carbonyl434compoundsR CH CH R' + HIOOH OH4RCHO + R'CHO + HIO + H O32R C C R' + HIOROH OHR4R C R + R' C R + HIO + HOO32O( 5 )By Ozonolysis of alkenes :This reaction is used to determine the position of double bond in alkene.RCH CH + O23 RCH OCH 2OOOzoneOzonideRCHO + HCHO –H O2ZnR CRCH + O23 R C COR RCH 2OOR–HO2ZnR CRO + HCHOUnb ranched alkenealdehyd eBranched alkeneketone( 6 )From Alkyne :( a )Hydration : With dil H SO & 1% HgSO at 60-80 C.2440CHCH + H O2[CH2CHOH] CH C H3O(Tautomerisation)

Other alkynes give ketone :CH C3OHCH 2CHC3CH + HO2CH C CH3O3(enol)( b )Hydroboration : Reaction with B H , 2BH or R BH give dialkyl borane.26321 – alkyne givesald ehyd eother alkyneketoneR CCH + R BH2CH C H + R BOH2O2R CH CHBR2HO22OH–RCH CHOHR TautomerismCH —C3C—CH + R BH 32  CH C CHBR 23CH 322 H O–OHCH C CHOH3R BOH+CH23CH C CH +R BOH 2O3CH 32( 7 )By Nef's reaction :Nitro alkanes are used in this reaction. The  of nitro alkane shows acidic nature.CH 2RCH N RNOOOHONaOHCH N RO NaO HO3CHO + N O + HO + NaOH22R(Nitro form)(Aci form) (Aldehyde)1° nitro alkaneCH NOORRCNOHORRNaOHCNO NaORRHO3C RRO + NO + HO + NaOH22 (Nitro form) (Aci form) (Ketone)2° nitro alkaneCNOORR RNaOHNo Reaction(3° nitro alkane)( 8 )By hydrolysis of carbonyl derivatives :R—CHN—OH2H O / HR—CHO + NH —OH2(Aldoxime)(Aldehyde) (Hydroxyl amine)CN OHRR2H O / HCO + NH2RROH (Ketoxime)(Ketone)C RHOROR2H O / HCO + 2ROHRH(Acetal)(Aldehyde) (Alcohol)C RROROR2H O / HCO + 2ROHRR(Ketal)(Ketone) (Alcohol)