carboxylic acid and its derivative

8/13/2019 Carboxylic Acid and Its Derivative

1/52

1. INTRODUCTION 2

2. METHOD OF PREPARATION OF CARBOXYLIC ACID 3

3. PHYSICAL PROPERTIES OF CARBOXYLIC ACID 7

4. CHEMICAL PROPERTIES OF CARBOXYLIC ACID 7

5. ACID DERIVATIVES 11

6. METHOD OF PREPARATION OF ACID DERIVATIVES 12

7. PHYSICAL PROPERTIES OF ACID DERIVATIVES 12

8. CHEMICAL PROPERTIES OF ACID DERIVATIVES 15

9. ESTERS 15

10. METHOD OF PREPARATION OF ESTERS 15

11. CHEMICAL PROPERTIES OF ESTERS 16

12. ACID AMIDES 18

13. PHYSICAL PROPERTIES OFACID AMIDES 18

1

CONTENTS

S.NO. TOPIC PAGE NO


2/52

Carboxylic Acid & It's Derivatives

1. INTRODUCTION :The compounds containing C OH as the functional groups are called as carboxylic acids.

OCarboxylic acids may be aliphatic or aromatic depending upon the group available on the carboxylic group.

R COOHAliphatic carboxylic acid

Aliphatic carboxylic acids :

Ar COOHAromatic carboxylic acid

These are further classified into mono, di, or tri carboyxlic acids depending upon the number of carboxylicgroups present.(a) Monocarboxylic acids.

e.g. HCOOH,CH3COOH

C3H7COOHDicarboxylic acid

COOH

Formic acidAcetic acid

Butyric acid

Methanoic acidEthanoic acid

Butanoic acid(b)

Oxalic acidCOOH

CH2 COOHCOOH

COOHCOOH

Malonicacid

(CH2)2 Succinic acid

CH2 COOH

CH2 GlutaricacidCH2 COOH

CH2 COOH

CH2

CH2 Adipic acid

CH2 COOHCOOH

(CH2)5COOHCH2 COOH

(CH2)6CH2 COOHCH2 COOH

(CH2)7CH2 COOH

COOH(CH2)8

COOH

Pimelic acid

Suberic acid

Azelaic acid

Sebacic acid

3

CARBOXYLICACID & IT'S DERIVATIVES


3/52


Aromatic acids :

(a) Monocarboxylicacids

COOHCOOH COOH COOHOH NH2 CH3

Benzoic acid

(b) DicarboxylicacidsSalicylic acid Anthranillic acid Toluic acid

COOHCOOHCOOH

COOH

COOH

Isopthalic acidCOOH

Terpthalic acidPthelic acid

2. METHOD OF PREPARATION OF CARBOXYLIC ACID :1. From Aldehydes and Ketones : Aldehydes and ketones are oxidised to carboxylic acids

RCHO + (O)Aldehyde

RCOOH

R CH2 C CH 2 R R CH2COOH + R COOHMixtureof carboxylic acidsO

Ketone

The oxidising agents which could be used are HNO 3 , acidic KMnO 4, acidic K 2Cr 2O7, andMn(CH3COO)2, and mild oxidising agents for aldehydes only.

FromAlcohols : Alcohols can be oxidised to carboxylic acids using oxidising agents. p-alcohols are oxidised to single carboxylic acids via aldehydes.s-alcohols are oxidised to mixture of carboxylic acids via ketones.

K 2Cr 2O7 + H 2SO4

2.

CH3CH2 OH +2 (O) CH 3COOH

K 2Cr 2O7 + H 2SO4CH3 CH CH 2 CH 3 + 4 (O) 2 CH3 COOHOH

CH2 OH CHO COOHK 2Cr 2O7 + H 2SO4 (O)

3. From the Hydrolysis of nitriles and isonitriles :to form carboxylic acids.

H+/H2O

Nitriles may be hydrolysed with acids or alkali

R C NR C OH + NH 3

O

3


4/52

Carboxylic Acid & It's DerivativesMechanism :

HFrom H2SO4 R C NH R C NHR C N: +

HSO4 . .

R C NHR C = NH

OH

H O2 O

HH

H+

From H SOTautomerisation

R C NH 3R C NH 22 4

OOHSO 4 H

HR C OR C OH H O2

OH+/H2O

O

R NC R NH + H COOH2Formic acid4. From Hydrolysis of Acid Derivatives : All acid derivatives may be hydrolysed is the presence

of dilute acids or alkali to formcarboxylic acids.H2O+ H+(a) R C X RCOOH + HX

OH2OR C OR + H+ R COOH + R OH(b)

O

R C NH 2H O

+ H+ 2(c) RCOOH + NH 3O

R C O C R H2O+ H+(d) RCOOH + RCOOHO

For acid hydrolysis to take place the group mustO

Mechanism : have lone pai r of electrons

. .. . . .e.g. X. . : O. R . NH2, , etc.

H

+ HR C OR R C O R O O

R C = O + R OHR C O R

O H

H2O HSO4 R C = O

OH

+ H2SO4.R C = O R C = OO

HH

= O is the criteria of reactivity of RCOOR for acid hydrolysis.Hence stability of R CR

R

R R So the reactivity towards acid hydrolysis is R CH 2COOR < CH COOR < C COOR .R

4


5/52

Carboxylic Acid & It's DerivativesBase Hydrolysis

OH /H2O R COO + HXR C X

OR C OR OH / H2O R C O + R OH

O

RCOO + NH3

OR C NH 2 OH / H2O

O

R C O C R OH / H2O R COO + RCOO

O O

Mechanism :

OH

R C OR

O

+ OR + OH R C OHR C O R OO

Reactivity of esters towards base hydrolysis is increased by the presence of strong-I groups at the - positions.

CH2 COOR

Cl

CH2 COOR NO2 > CH3COOR .>

The general reactivity of the acid derivatives for hydrolysis isR C O C R R C OR R C NH 2RCOX > > >

OO O O

This is because the leaving group ability order is O C R X > > OR > NH 2.

OFrom Grignards Reagent :

CO2

5.

H+/H2OR C OMgXRMgX RCOOH + MgXOHDry ether O O

COOHC OMgX

CO2 H2O/H+C6H5MgX + MgX (OH)Dry ether

6. From Sodium Alkoxides :Under presure H+/H2ORONa + CO RCOONa RCOOH + Naand temperature

7. From Dicarboxylic Acids : When Dicarboxylic acids (geminal) are heated then they undergoeasy decarboxylation to form monocarboxylic acids.

COOH COOHR CH COOH

HCOOH + CO 2R CH2COOH + CO 2

COOH

5


6/52

Carboxylic Acid & It's DerivativesMechanism :

O

R CH C OR CH COOH

COOHH+

O C OH

O R CH HR CH C OH C = O HR CH C OH +

Stablized due to resonanceOH OH

R CH COOH

Z

CH2 Z + CO 2 where Z = OH, NH 2, C R , COOH,

Here it would be r ight to say tha t any molecule of the type would undergo

decarboxylation readily to form R

O

C H etc.O

e.g. COOH CH 2 COOH

From Alkane :

CH3COOH + CO 2

8.Mn (CH3COO)2

underureMn (CH3COO)2

underure

3R CH3 + 2 O2 R COOH + H 2O

3CH3 CH3 + 2 O2 CH3COOH + H 2O

9. From Alkene : Alkenes when heated with carbon mono-oxide and water at 573 K with H 3PO4as catalyst give carboxylic acid.

H3PO4(a) CH2 = CH2 + CO + H 2O CH3 CH2 COOH

CH3

573 673 K

H3PO4CH COOHCH3 CH = CH 2 + CO + H 2O 573 673 K CHUnder presure 3

(b) Alkenes on oxidation with hot KMnO 4 give carboxylic acids.R CH = CH 2 + Hot KMnO 4

Manufacture of HCOOH :RCOOH + CO 2 + H2O

Formic acid is manufactured by reacting sodium hydroxide and carbon monoxide at high prressureand temperature.

O+H /H2O6 - 10 atm

473 K H C OH

O NaOH + CO H C ONa

Manufacture of CH 3COOH :(a) From Methanol : Methanol and carbon monoxide when heated in the presence of Rhodium gives

acetic acid.

CH3 C O HRhCH3OH + CO O(b) Ethanol is converted to acetic acid by acetobector.

Acetobactor C2H5OH + O 2 CH3COOH + H 2O

6

St


7/52

Carboxylic Acid & It's DerivativesPreparation of Benzoic acid

COOHCH3

3 CoMn acetate+ 2 O2 + H2O

CCl3 COOHCa (OH) 2

Fe+ 3H2O + 3HCl

3. PHYSICAL PROPERTIES OF CARBOXYLIC ACID :

1. The first three acids are colourless, pungent smelling liquids. The next four smell like bitter goats butter where as higher members are colourless solids.Solubility, the lower aliphatic carboxylic acids are soluble in water. While the higher members areinsoluble.

The boiling points of carboxylic acids is even more than alcohols.The melting points of carboxylic acids show alteration effect or oscillation effect. The melting pointsof even members is always higher than the next higher or lower odd number acid. This is because evennumber acids is more symmetrical and fits well into the crystal lattice and more energy is required to

break them.

2.

3.4.

CH2 CH2COOH CH2

CH2

Butanoic acid

CH2

Pentanoic acid

CH3 CH3 COOH

Butanoic acid has higher melting point than pentanoic acid.

4. CHEMICAL PROPERTIES OF CARBOXYLIC ACID :

(A) Reactions : Due to R C O HbreakageO

1R C ONa1. RCOOH + Na + 2 H2O

2RCOOH + Zn R C O Zn + H2O 2

This shows the acidic character of RCOOH.2. With NaOH

RCOOH + NaOH RCOONa + H 2OAll carboxylic acids in alkali to form salt of metal.

3. With Na 2CO 3 and NaHCO 3Carboxylic acids decompose carbonates and bicarbonates to carbondioxide2RCOOH + Na 2CO3 2Na (COO R) + CO 2 + H2O

RCOONa + H 2O + CO2R C OH + NaHCO 3O

7


8/52


(B) Reactions involving R C OHbreakage

O1. Reactions with ammonia

O

H ORCOOH + NH 3 RCOONH 4 R C NH 2CH3 C NH2

2

CH3 C ONH 4CH3 C OH + NH 3 OO

2. Reactions with Alcoholsconc.H2SO4

O

R C OH + R OH R C OR + H2OOO

Mechanism :

R C O

OH

. .R C OH

+ HR C OO

R C OH R C = O H

OH OHOH

Resonance stablized

H R O

R C OH + R OH R C OH

OH OH

-HSO4 OHOHH

R H2OR C OR R C OR R C O + H2SO4

O H OOH

Hence the reactivity of ester depends upon the steric hindrance created by the alkyl group (R) in

R C O . Hence the reactivity of acids towards esterification reaction is

OH

R

R

R CH COOH R C COOR CH2COOH > > R

While the reactivity order of alcohol towards esterification reaction is p- > s- > t-.3. Reaction with P 4O 10

When carboxylic acids are heated with phosphorus pentaoxide, then dehydration of carboxylic acids toform carboxylic acid anhydride occurs.

R C O R C O R C O C R P4O10+ OO O O

O OCOOH P O C O C 4 102

8


9/52


4 . Reaction with PCl 5, PBr 5, PBr 3 or SOCl 2When reacted with PCl 5 or SOCl2 then carboxylic acids give acid chloride

R C OH R C Cl+ PCl5 + HCl + POCl 3O

R C OH

O

R C Cl+ SOCl2 + SO2 + HClO

3 R C OH

O

R C Br + PBr 3 + H3PO3O

(C) Reactions involving

O

R C OH

O

Decarboxylation Reactions : The removal of carboxylic acid is called decarboxylation. It can be brought about by two methods.

(i) Chemical Decarboxylation : (Soda lime decarboxylation) Sodium or potassium salts of carboxylicacids on heating with soda lime give alkane with one carbon atom less.

CaORCOONa + NaOH R H + Na CO .2 3

(ii) Electrolytic Decarboxylation :ElectrolysisRCOONa + 2H 2O R R + 2CO 2 + 2NaOH + H 2.

Reaction to Alcohols :

All carboxylic acids are reduced to alcohols using copper chromite, or LiAlH 4, or H2/Ni, or Pt or Pd, or

Na/EtOH.

CuO + CuCr 2O4R C OH RCH2 OHO

The catalyst copper chromite is called Adkins catalyst.

Reaction to Alkanes :All carboxylic acids are converted to alkanes on heating wtih HI/Red P.

Red PR C OH + 6HI R CH3 + 2H2O + 3I2473 K O

Reactions corresponding to Alkyl Groups Hell Volhard Zelinsky Reaction (HVZ Reactions)The carboxylic acids having -H atoms on halogenation in the presence of red phosphorus form a- haloacids

Red P R CH COOHR CH2 C OH + X2O

Mechanism 2P + 3X 23R CH2 COOH +

X

2PX3PX3 + H3PO33 R CH2 C X

O

+ HXR CH2 C X + X2 R CH C X

O OX

9


10/52


R CH C X + R CH2COOH R CH C OH + R CH2 C X

O OX O X

The compound R CH2 C X proceeds through enolization of acid halide which undergoes easyO

halogenation.R CH2 C X R CH = C X

OHO

R

CH = C X

:OH

X

R CH C XX

R CH C XX XO H O- OX

This is a very important reaction because the X (Cl or Br) can easily be replaced by strong nucleophiles likeCN, NH2, etc, form substituted acids.

R CH COOH

X

+ NH3 R CH COOH

NH2

R CH COOH

X

+ aq.NaOH R CH COOH

OH

+ alc.KOH R CH = CH COOHR CH2 CH COOH

X

KCNR CH COOH

X

R CH COOH

CNARNDT EISTERT SYNTHESIS : - It is the conversion of lower carboxylic acids to higher carboxylicacid

i) CH3 NH2ii) H2O

PCl5R C OH R C Cl R CH2COOH

O O

Ex.1 Anester ofmolecular formula C H O onhydrolysis affords anacid(A) and an alcohol (B). Oxidation8 16 2of alcohol (B) with Na Cr O gives rise to an acid (C). Sodiumsalts of acids (A) and (C) on fusion with

2 2 7

solid NaOH yield propane in each case. What is the structural formula of the originalester ?

O

CH CH CH C OCH CH CH CH H OH CH CH CH COOHSol. H3 2 2 2 2 2 3 3 2 2(A )

CH3CH2CH2CH2OH(B)

Compound (A), C H Cl, reacts with alcoholic KOH to form (B), C H . Compound (B) dischargesEx.2 3 7 3 6Br /CCl solution. Reaction of (A) with Mgin ether and subsequent treatment with CO and dilute acid2 4 2

gives (C). whose molecular formula is C H O . When we add compound (C) to aqueous NaHCO4 8 2solution, bubbles are evolved. What are (A) to (C)?

3

10


11/52


COOH

CH

CH3

Cl

CH

CH3

(A) H3C (B) H3C (C) H3CCHSol.CH2

5. ACID DERIVATIVES :General :

A functional derivative of a carboxylic acid is a compound formedby replacement of the hydroxyl group of theacid by some other group, say Z, that can be hydrolysed back to the parent acid.

Members :

Four important classes of acid derivatives are1.2.3.4.

EstersAcid anhydridesAcid chloridesAcid amides

RCOOR RCOOCOR RCOClRCONH

2Where R and R stand alkyl or phenyl groups.All these compounds contain the acyl group (RCO) and hencethey are also known as acyl compounds.

Nucleophilic Acyl substitution :

The presence of the carbonyl group in the acid derivatives brings on these molecules certain characteristicreactivity.

Thus theacyl compoundsundergo nucleophillic substitution inwhichOHof theacid, Cl of the acid chloride, OOCR of the acid anhydride, NH 2 of the amide and OR . of the ester is replaced by some other basicgroups. This is possible only due to the presence of the carbonyl group because nucleophillic substitution doesnot usually take place at a saturated carbon atom.

R C = O + Z R C Z + Nu

NuO

Where Z stands for OH, Cl, OOCR, NH 2 or OR .The above nucleophilic acyl substitution proceeds by two steps :Intermediate formation of a tetrahedral anion.

This step is affected by two factors :(a) Favoured by electron-wtihdrawl which stabilizes the developing negative charge on the oxygen

atom.(b) Steric hinderence by the presence of bulky groups which become crowded together in the transition

state.Ejection of Z group and returning to a trigonal compound.This step depends upon the basicity of the leaving group; Weaker the base, better the leaving group.

Non-Occurance of acyl nucleophillic substitution reactions in aldehydes and ketones.Acid derivatives show acyl nucleophillic substitution reactions while aldehydes and ketones do not show thesereactions. This is explained on the basis of following two reasons :

(1)

(2)

11


12/52

Carboxylic Acid & It's Derivatives(1) Stability of the intermediate tetrahedral anion :

Theattack of thenucleophile on theacyl carbonatom of the acid derviatives produces a less stable intermediate

:Z:

(tetra hedral anion R C O due to the presence of an additional electron with drawing group Z, while the-

Nu R

intermediate obtained during such an attack on aldehydes and ketones ( R C O ) where R and R may be alkyl

Z

or hydrogen) is more stable. This results in the ejection of group Z to form stable trigonal compound.

(2) Basicity of the leaving group :

The ease with which a group is lost depends upon its basicity; the weaker the base, the better the leavinggroup. The hydride ion (H O- ) or alkiyde ion (R O- ) are the leaving groups of aldehydes and ketones whereasClO- , RCOO , R O O- and NH2 are the leaving groups of acid derivatives i.e., acid chlorides, anhydrides,

ester and amides respectively. Cl , RCOO etc, are comparatively weaker bases than H O- or R O- ions. Rather HO- and R O- are the strongest bases of all. So aldehydes and ketones show nucleophillic addition reactions

instead.The order of reactivity of the acid derivatives towards nucleophillic acyl substitution has been found to be :RCOCl > RCOOCOR > RCOOR > RCONH 2.

Acid Chlorides

6. METHOD OF PREPARATION OF ACID DERIVATIVES :

(a) By the action of PCl 5 or PCl3 on the carboxylic acids.RCOOH + PCl 5 R C Cl + POCl 3 + HCl

O

C6H5COCl + POCl 3 + HCl

CH3 C Cl +H3PO3.

C6H5COOH + PCl 5CH3COOH + PCl 3

O

By the action of thionyl chloride on carboxylic acids.

CH3 C Cl

(b)

CH3COOH + SOCl 2 + SO2 + HClO

(c) From benzaldehyde : By passing chlorine through benzaldehdye .

CHO COCl

+ Cl2 + HCl

7. PHYSICAL PROPERTIES OF ACID DERIVATIVES :

Hydrolysis :Acid halides are hydrolysed by water to the parent acid.

R C Cl + H2O + HClR C OHO O

12


13/52

Carboxylic Acid & It's DerivativesAliphatic acid halides are hydrolysed in cold water but benzoyl halide is hydrolysed very slowly in cold water in alkaline medium.

Alcoholysis :Treatment of acid halides with alcohols, give esters.

PyridineR C Cle.g. + R OH R C OR + HClO O

Pyridine C OR C Cl + R OH + HClOO

OH O C Cl aq.NaOH C O + + HCl

O

The function of pyridine is to remove HCl.

Ammonolysis :

With ammonia acid halides give amidesR C NH 2R C Cl + 2NH3 + NH4Cl

OO

R C Cl R C NH R + R NH2 + NH4ClO O

NH2O O

C Cl C NH +

In all these reaction aliphatic acid halides react faster than aromatic acid halides.Reactions with carboxylic acid or sodium carboxylate.

Acid halides form anhydrides with carboxylic acids or sodium carboxylates.

R C O C R R C OH + R C Cl Pyridine + HClO O OO

R C ONa R C O C R + R C Cl + NaClO OO

Reaction with KCN :

O

Since cyanide ion is a strong nucleophile than water, therefore it reacts with acid chlorides to form alkanoylcyanides.

R C Cl R C CN+ KCN + KClO O

The hydrolysis of alkanoyl cyanides give keto acidsH+/H2O

R C COOHR C CN

OO

13


14/52


Reaction reactions :When reduced with hydrogen in the presence of finely-divided polladium on BaSO 4 and sulphur acid chloridesare reduced to aldehydes (Rosenmund Reaction)

Pd/BaSO 4 + SR C Cl + H2 RCHO + HCl

O CHOCOCl Pd/BaSO4 + S

+ H2 + HCl

Reactions of Benzene ring in aromatic acid halides :Since COOH, COCl, COOR , C O C C groups are all strong deactivating groups and electophillic

O Osubstitution reactions take place at meta position.

AcidAnhydrides :

Acid anhydrides may be regarded as derived by the removal of one molecule of water from two molecules ofcarboxylicacids.

Preparation :

(a) From carboxylic acids

R C OH + P2O5 + HPO3 Metaphosphoric acidR C O C R O O O

(b) From sodium carboxylate and acid chlorides

R C ONa + R C Cl + NaClR C O C R

OFrom Acetylene

O O O(c)

O

O C R

O C R HgSO4 + SH C C H + 2 R COOH + CH CH3

O

O

O C R

O C R distill CH3CHO + R C O C R CH3 CH

O OO

(d) From acetic acid and ketones:AlPO4

CH3COOH CH 2 = C = O + H 2O970 K

CH3 C O C CH 3CH2 = C = O + CH 3COOH O O

14


15/52


8. CHEMICAL PROPERTIES OF ACID DERIVATIVES :

(a) Hydrolysis :All acid anhydrides undergo hydrolysis both acid catalysed and base catalysed to give acids. The basecatalysed hydrolysis is more rapid..

R C O C R + H2O RCOOH + RCOOHO O

(b) Alcoholysis :Acid anhydrides react with alcohols to form esters.

R C O R R C O C R + R OH + RCOOHOO O

(c) With ammonia :Acid anhydrides react with ammonia to form amides.

CH3 C O C CH 3 + NH3 CH3 C NH 2

O O Oacetamide

+CH3 C O NH 4

OAmmonium acetate

(d) Friedal Crafts Acylation :

OAnhyd.AlCl 3 C R + R C O C R

O O

9. ESTERS :Nomenclature

O

Common name IUPAC name

Methyl formate MethylmethanoateH C OCH 3

OEthyl acetate EthylethanoateH3C C OC 2H5

OMethyl benzoate MethylbenzoateC6H5 C OCH 3

10. METHOD OF PREPARATION OF ESTERS :

(1) From diazomethaneEther N2

RCOOH +Carboxylic acid

CH2 N2Diazomethane

RCOOCH 3Methyl ester

CH2 N2Diazomethane

H3CCOOHAcetic acid

Ether N2

+ H3CCOOCH3Methyl acetate

15


16/52

Carboxylic Acid & It's Derivatives(2) By Tischenko reaction

OEther

Aluminiumethoxide

H3C CHO + CH 3CHOAcetaldehyde

(two molecules)

H C C OC H3 2 5 H2O Ethyl acetate

11.

(1)

CHEMICAL PROPERTIES OF ESTERS :

Hydrolysis : It is the reverse of esterification.They undergo hydrolysis both in acidic as well as in basic medium.

OOH+

R C OR' + H OH R C OH + R'OHAlcoholEster Carboxylic acid

OOH+ H C C OH + CH OHH3C C OCH 3 + H OH 3

Acetic acid

3

Methyl alcoholMethyl acetate

(2) Ammonolysis : It leads to the formation of acid amides.

OO

R C NH 2Acid amide

+ R'OHAlcohol

R C OR' + NH 3 NH2 H

Ester

O O

H3C C OC 2H5 + H NH 2Ethyl acetate

H3C C NH 2 + C2H5OHAcetamide Ethyl alcohol

(3) Alcoholysis or trans-esterification

O O+H or

RO Na+R C OR"

New Ester + R' OH

New AlcoholR C OR'

Ester + H OR"

Alcohol

O O+H3C C OC 2H5 + H O C 4H9 H H3C C OC 4H9 + C2H5OH

n-Butyl alcoholEthyl acetate n-Butyl acetate Ethyl alcohol

(4) Reaction with Grignards reagent : Esters, react with Grignards reagent to form alcohols,

16


17/52


18/52


19/52

Carboxylic Acid & It's Derivatives(4) Dehydration :

OP2O5/ H2O

R C NAlkyl cyanideR C NH 2

Acid amide

OP2O5/ H2O

H C C N3H3C C NH 2 Ethane nitrileAcetamide

OP2O5/ H O

C6H5 C NBenzene nitril

C6H5 C NH 2Benzamide

Reaction :

O

2

(5)

LiAlH4/ether R CH2 NH 21 AmineR C NH 2

Acidamide H2O

OLiAlH4/ether H3C CH2 NH2

Ethyl amineH3C C NH 2Acetamide

H O2

19


20/52


Ex.1 Treatment of 2, 4-pentanedione with KCN and CH COOH, followed by hydrolysis yields two prod-3ucts, (A) and (B). Both (A) and (B) are dicarboxylic acids of formula C H O . (A) melts at 98C.7 12 6Whenheated,(B)gives first a lactonic acid (C H O ) and finally a dilactone (C H O ).7 10 5 7 8 4

(a) What structure must (B)have that permits readyformation ofbotha monolactone and a dilactone?(b) What is the structure of (A) ?

CH3 CH3 CH3 CH3C O HO C COOH HO C COOH HOOC C OH

CH2( i ) K CN / CH3 COO H CH2 CH CH22(ii)H3O

C O HO C COOH HOOC C OH HO C COOHSol.CH3 CH3

(A) Meso

CH3 CH3Racemic

(B )

Compound (B) is a recemic modification. It gives monolactone (II), but the remaining OH and COOHare cis; (II) canreact further to form the dilactone.

OOH OH OH COOH

C

O CCH2

C O

CH2

C OH3C C CH2 C CH3 C C C H2 O

COOH COOH H3C O CH3 H3C O

CH3

(B) (II) Monolactone Dilactone

(A) is the meso compound. It gives monolactone (III); here, the remainingOHand COOHaretrans, and further reaction isnot possible.

OH COOH OH CH3CH2

C O H2O H3C C CH2 C COOH C C

COOH OH H3C O COOH

(A) Monolactone

Ex.2Sol.

Acarboxylic acid does not forman oximeor phenyl hydrazone. Explain.It is because, carboxylic group does not have a free carbonyl group. Actually carboxylic acidsundergoes resonance.

..O: .. :O :

.. +R C = O HR C O.. H

Due to resonance bond of COOH group acquires partial double bond character andC = O

cannot show reactions with hydrazine, hydroxylamine etc.

20

SOLVED EXAMPLE


21/52

Carboxylic Acid & It's DerivativesThe reaction between H 3CCOOC2H5 + H2O CH3COOH+ C2H5OH is slow to start with, but

becomes fast later on. Why?Ex.3

Sol. H3CCOOH + C 2H5OHAcetic acid Ethyl alcohol

H3C COOC 2H5 + H2OEthyl acetate

CH3COO + H+H2CCOOH

Acetic acid produced in the above reaction,providesH+ ions and catalyses the hydrolysis of ester. This isanexample ofauto catalyst.

(a)Acid halides of formic acid are unstable. Why ?(b)Formic anhydride cannot be prepared by heating.

Ex.4

C O bond is a very stable bond due to large Hf of CO so the decomposition reactionO

Sol. (a)

C O + HX is favoured. Formyl chloride is not stable above 60C.H C X(b) This isbecausedehydration occurs intramolecularly rather thanintermolecularly.

HCOOH CO + H 2O

Ex.5 Anorganic compound (A)of formula C H O decolourises Br /CCl colour but has no reaction with6 10 2 4ammonical cuprous chloride solution. (A) reacts withSchiffs reagent andalso reduces Fehlings solu-

tion. (A) on treatment with silver oxide suspended in aqueous base gives compound (B). C H O ,6 10 2which evolves CO from aqueous NaHCO . (B) on ozonolysis yields one mole each ofpropanal

and2

pyruvic acid. What are (A) and (B) ?3

Sol. Compound (A) contains olefinicdouble bond asit discharges the redcolour ofBr /CCl . It alsocontains2 4 CHO group as it gives positive tests for this group. Since comound (B) liberates CO from NaHCO2 3hence it contains COOHgroup. the structure of (B) isdetermined fromits productsofozonolysis asfollows :

H H COOHCOOHC

C2H5

O O C 2[O ] CC2H5

CCH3 CH3

(A)Pyruvic acidPropanal

Since (B) isobtained by the oxidation of (A) hence (A) is :H CHO

CC2H5

CCH3

Ex.6 Asalt (A) of the formula C H O Ag on refluxingwith bromine gives (B), C H Br. Compound (B) on4 5 2 3 5heating with alcoholic KOH yields (C), C H , which decolourises Br /CCl and cold dilute KMnO3 4 2 4 4solution, but doesnot react with ammonicalAgNO or Cu Cl . (C)on ozonolysis gives (D),C H O ,3 2 2 3 4 4which on heating eliminates CO to give acetic acid. What are (A) to (D)?2

H2CH2CKOH Br 2 CH COOAg CH Br Sol. C2H5OHReflux

H2C H2C(A) (B)

H2C COOH (i) O 3 H2C CH3COOHCH CO 2(ii) H 2O

Acetic acidCOOHHC(C) (D)

21


22/52

Carboxylic Acid & It's DerivativesEx.7 Fluorine is more electronegative than chlorine even then, p-fluorobenzoic acid is a weaker acid than

p-chlorobenzoic acid. Explain.Since the compound aremore electronegative than carbonand also possesses lone pairs of electrons,therefore, they exert both I and +R effects. Now in F, the loneof electrons are present in 2p-orbitals

but inCl, theyare present in3p orbitals. Since 2p-orbitals of F and C areof almost equal size, therefore,

the +Reffect ismore pronounced inp-Fluorobenzoic acid thaninp-Chlorobenzoic acid.

Sol.

2 p 2 p2 p 3 p

COOH COOHF Cl

Stronger +R-effect Weaker +R-effect

Thus inp-Fluorobenzoic acid +Reffect outweighs the I effect but inp-Chlorobenzoic acid, it is the Ieffect whichout weighs the +R effect. Hence p-Fluorobenzoic acid is weaker thanp-Chlorobenzoicacid.

Benzamide is lesseasily hydrolysed thanmethyl benzoate. Why ?

..

Ex.8

..O : : O:.. +

NH2C6H5 CSol. C6H5 C NH 2(I) (II)

Resonating structures of Benzamide

.. ..O : : O:

.. +C6H5 C O.. CH3C6H5 C O.. CH3

(III) (IV)

Resonating structures of methyl benzoate

Since N is less electronegative thanoxygen, therefore, N can donate a pair of electrons more readilythan oxygen. Therefore,magnitude of positive charge on carbonyl carbonin benzamide is less than inmethyl benzoate. Thus duringhydrolysis, attack of OH ion on carbonyl carbon inbenzamide isdifficultthan inmethyl benzoate.An organic acid (A) on heatingwith AlPO 4 at 700C forms (B). Compound (B) also reacts with(A), togive (C). Compound(C) on reaction with 1, 3, 5-trimethyl benzene in presence ofAlCl 3 gives a ketone(D) and CH3COOH. (D)on treatment with Na(Hg)/HCl gives anaromatichydrocarbon E. Givestructuresof (A) to (E) with proper reasoning.

Ex.9

Sol. (a) The reaction of compound (B) with (C) to form a ketone (D) and acetic acid is an example

of Friedal Craft acylation. Hence (C) should be an acyl chloride or an acid anhydride.Since CH 3COOH ia also formed in the reaction (C) must be acetic anhydride. Had these been acetyl chloride or any other acid chloride HCl should have been there instead toCH3COOH.So the reaction canbe represented as under.

CH3

(b)

CH3

AlCl3 H3C CH3+ (CH3CO)2O + CH3COOHCOCH3

(D)

H3C CH3

22


23/52


24/52


Q.1 Two isomeric carboxylic acids H and I, C H O , react withH /Pdgiving compounds C H O . H gives9 8 2 2 9 10 2a resolvable product and I gives a nonresolvable product.Both isomerscan be oxidizedto C H COOH.6 5Give the structure ofH and I.

Identify the products (A), (B), (C) and (D)in thefollowing sequence :C15H31COOH (A) (B) ( ii) O (C) (D)

Q.2LiAlH4 KMnO 4 conc.H 2SO4HCl (i )Mg , ether

Q.3 A neutral liquid (Y) has the molecular formula C H O . On hydrolysis it yields an acid (A) and an6 12 2alcohol (B). Compound (A) has a neutralization equivalent of 60.Alcohol (B) is not oxidized byacidifiedKMnO , but givescloudiness immediately with Lucas reagent. What are (Y), (A)and (B) ?4Esterification does not take place inthe presence of ethyl alcohol and excessof concentrated H SO atQ.4 2 4170C. Explain.Whydoes carboxylic acid functions as bases though weakones?

Which ketoneof the formula C H O will yield an acid onhaloform reaction?Q.5

Q.6

Q.7

Q.8

Q.9

Q.10

Q.11

5 10

Highly branched carboxylic acids are lessacidic thanunbranched acids.Why?

Acarboxylic acid doesnot formanoxime or phenyl hydrazone. Why?

Formicacid reduceTollens reagent. Why?

The K for fumaricacid is greater thanmaleic acid.Why.2dentify the finalproduct inthe followingsequence of reaction.

O

H2C CH2C H3 CH 2 MgBr X

H3O Y K Mn O 4Z

Q.12 What is (Z) in thefollowing sequence of reactions?

(i ) NaOH / B r 2(ii ) H 3O

( i ) 2 NaN H 2(ii) 2CH 3

HgSO 4 (Y)HC CH (X) (Z)H 2SO4Q.13

Q.14

Acetic acid has a molecular weight of 120 inbenzene solution why ?Place the following in the correct orderofacidityCH CCOOH;

( )CH2=CHCOOH;

(CH3CH2COOH

( )Q.15

Q.16

Q.17

Phenol isa weaker acid than acetic acid why ?Which acid derivative show most vigorous alkaline hydrolysis ?

59 g ofamide obtained from thecarboxylic acid RCOOH,onheating with alkali gave 17gofammonia.What is theformula ofacid ?

Which carboxylic acid (X)of equivalent mass of52g / eq loses CO 2 whenheated to give anacid (Y) ofequivalent massof 60g/eq.Which of thereagent reacts with C 6H5CH2CONH2 to form C6H5CH2CN.

Consider the following ester

Q.18

Q.19

Q.20

(I) MeCH COOH (II) Me CHCOOH2(III) Me CCOOH2

(IV) Et CCOOH3 3Correct order of therateof esterification

24

EXERCISE-I


25/52

Carboxylic Acid & It's DerivativesQ.21 Anorganic compound (A) on treatment with ethyl alcohol gives a carboxylic acid (B)and compound

(C). Hydrolysis of (C) under acidic conditions gives (B) and (D). Oxidation of (D) with KMnO also4

gives (B). (B)on heating with Ca(OH) gives (E) (Molecular formula C H O) (E) doesnot givesTollens2 3 6test and doesnot reduce Fehling solution but forms 2, 4dinitrophenylhydrazone. Identify (A) to (E).

Two mole of an ester (A) are condensed in presence of sodium et ho xide to give a

B -keto ester (B) and ethanol. On heating in an acidic solution (B ) gives ethanol and a -keto acid (C).On decarboxylation (C) gives 3-pentanone. Identify (A), (B) and (C) with proper reasoning and givereactions.

Compound(A) (C H O ) on Reaction with LiAlH yielded two compounds (B) and (C). The com-

Q.22

Q.23 6 12 2 4 pound (B) on oxidation gave (D) 2 moles of (B) on treatment with alkali (aqueous) and subsequentheating furnished (E).The later on catalytic hydrogenation gave (C).Thecompound (D) wasoxidizedfurther to give(F) whichwas found to bemonobasic acid (m.wt.60.0). Deduce structures of(A) to (E).

Compound (A) C H O liberated CO on reaction with sodium bicarbonate. It exists in two formsQ.24 5 8 2 2neither of which isoptically active. It yielded compound (B). C H O on hydrogenation. Compound5 10 2(B) canbe separated into enantimorphs. Write structuresof (A) and (B).

The sodium saltof a carboxylic acid, (A) was producedbypassing a gas (B) into aqueous solution of caustic alkali at anelevated temperature and pressure (A) on heating in presence of sodiumhydroxidefollowed bytreatment with sulphuric acid gave a dibasic acid (C).Asampleof 0.4g of (C) on combus-tiongave 0.08 g ofH Oand 0.39 g ofCO . The silver salt of the acid,weighing 1.0g,on ignition yielded

Q.25

2 20.71 g ofAgas residue. Identify (A), (B) and (C).

Anorganiccompound(A) on treatment with acetic acid inpresence of sulphuricacid produces anester (B). (A) on mkild oxidation gives (C). (C) with 50% KOH followed by acidification with diluteHClgenerates (A) and (D). (D)_ with PCl followed byreaction with ammonia gives (E). (E) on dehydration

Q.26

5

produceshydrocyanic acid. Identify (A) to (E).

Acetophenone on reactionwithhydroxylamine-hydrochloride can produce two isomericoximes.Writestructures oftheoximes.

Anacidic compound (A),C H Oloses itsoptical activity on strong heating yielding (B).C H O which

Q.27

Q.28 4 8 4 6 2reacts readilywith KMnO . (B) formsa derivative (C)with SOCl , whichon reaction with (CH NH4 2 32gives (D). Thecompound (A)on oxidation with dilute chromic acid gives an unstable compound (E)which decarboxylates readily to give (F), C H O. The compound (F) gives a hydrocarbon (G) on

3 6

treatment withamalgamated ZnandHCl. Givestructures of (A) to (G)with proper reasoning.

Anorganic acid (A),C H O reacts with Br in thepresence ofphosphorus to give (B).Compound(B)Q.29 5 10 2 2contains an asymmetric carbon atom andyields (C) on dehydrobromination. Compound (C) doesnotshow geometric isomerism and on decarboxylation gives an alkene (D) which on ozonolysis gives (E)and (F). Compound (E) gives a positive Schiffs test but (F) does not. Give structures of (A) to (F) withreasons.

Anliquid (X)having molecular formula C H O ishydrolysed with water inpresence ofanacid to giveQ.30 6 12 2a carboxylic acid (Y)and an alcohol (Z). Oxidation of (Z) withchromic acid gives (Y). What are (X),(Y)and (Z) ?

25


26/52


Q.1 (a) Give the structuresof the four optically-active isomers of C H O (D through G) that evolve CO4 8 3 2with aq. NaHCO .3(b) Find the structure of (D), the isomer that reacts with LiAlH to give anachiral product.4

(c) Give chemical reactions to distinguish among (E), (F) and (G).Complete thefollowing equation:

CH3

Q.2

HCl Mg CO2 H2 O/ H ? ? ? ?Peroxide Ether H3C C CH2

Q.3 Give structuresof compounds:

(G) C O2 (H) H 3O ( I)Acetylene + CH MgBr (C H O )3 CH 4 3 2 2H 2 O , H2S O4 (J) (C H O ) K Mn O4 CH (COOH)HgSO4 2 23 4 3

Q.4 Anester C H O washydrolysed with water anacid (A), and analcohol (B), were obtained. Oxidation6 12 2of (B)with chromicacid producedA.what is the structureof theoriginal ester? Write equationsfor allthe reactions.

Complete thefollowingequation :

RCO 2H ? ? ( inert solv ent ) ? ?

Acid halides of formic acid areunstable. Why?

What is theproduct of thefollowing reaction?

Q.5SOCl2 NaN3 D Hydrolysis

Q.6

Q.7

CHOH ( i ) Silver oxide in a.q. ba se ?C C (ii)H

CH3H3C2-Methyl-2-pentenal

Q.8 Anunsaturated acid(A)of molecular formulaC H O eliminates CO easilyand gives anotherunsatur-5 6 4 2ated acid (B) of formula C H O . Bysaturation with H /Pt (B)gives butanoic acid. Neither (A) nor (B)4 6 2showscis-trans isomerism. What are (A) and (B)?

2

Q.9 Anorganic compound Aon treatment with ethyl alcohol gives a carboxylic acid Band compoundC, Hydrolysis of Cunder acidic conditions gives Band DOxidation of D, with KMnO also

4

gives B. Bonheating with Ca(OH) gives E(molecular formula C H O). Edoesnot giveTollens2 3 6test anddoes not reduceFehlings solution but forms a 2,4-dinitrophenyl hydrazine. Identify A. BCDand E.

Two moles of an ester (A) are condensed in the presence of sodium ethoxide to give a -keto ester (B)and ethanol. On heating in an acidic solution (B) gives ethanol and -keto acid (C). On decarboxylation(C) gives 3-pentanone. Identify (A), (B) and (C) with proper reasoning. Name the reaction involved intheconversion of (A) to (B).

Analkali salt ofpalmitic acid is knownas ?O||

Acid do not react with sodium bisulphite though they have C group why ?

Q.10

Q.11

Q.12

26

EXERCISE-II


27/52


n thereaction sequence

X C a( O H ) 2Y

Q.13dry conc Acetone H 2SO 4 Zdistillation

X,Y and Z are ?

[ o]Q.14 CH3

CH2

COOH X, Product X is SeO 2

Q.15

Q.16

Whichof the reagent attack onlythe carbonyl group of a fattyacid ?

In thesequenceCH 3 C H3CH

|| | | |ZX YCH CHO COOH CH 4

The reagent X,Y, and Z are

In thereaction sequenceQ.17 NH Br 2Y 3 Z CH3 NH2X H3 O KOH

X,Y and Z are ?

An acid X react with PCl 5 to forma compound (Y). X also react with NaOHto forma compound(Z).Both Y and Z react together and from (E), E react with a reagent (F) to givebackcompound(Y) whatare X,Y, Z, E and F ?How willyou synthesise ?

(A)Acetyl chloride frommethyl chloride(B)Acetamide from ethyl alcohol(C) Ethyl acetate from acetic acid

Complete thefollowing reaction ?

Q.18

Q.19

Q.20

OOCH3

(a) X +CH3

O NHY O + Z NHOOO

NH 2(b) O + E F + C2H5OH

P C l 3 NH2

NH 2(c) X + O H Cl Y Z C H 2 O

NH2

Resin U rea

Q.21 Complete thefollowing equations: (i) CH CH CH CH Br C N ? H 2 O / H ?3 2 2 2

CH3

CN ? ? H OH ?

H2SO4

C old conc . S OC l2 ? Mg ? ( i) C O2H3C C Br ?(ii) (ii) HEther CH3

Identifythecompounds:

1, 4-Cyclohexadiene + CHBr t Bu OK (D) (C H Br ) K Mn O4 (E) (C H Br O ) H 2Q.22

7 8 2 7 8 2 4 Ni3

(F) (C H O ).7 10 4

27


28/52

Carboxylic Acid & It's DerivativesQ.23 Compound(A)C H O liberated carbon dioxide on reaction with sodium bicarbonate. It exists intwo5 8 2

forms neither of which is optically active. It yields compound (B) C H O on hydrogenation.5 10 2Compound(B) can beseparated into two enantiomorphs. Write the structural formulae of (A) and (B)giving reason.

Anacidic compound (A), C H O loses itsoptical activity onstrongheating yielding (B), C H O whichQ.24 4 8 3 4 6 2reacts readily with KMnO . (B) forms a derivative (C) with SOCl , whichon reaction with (CH ) NH4 2 3 2gives (D). Thecompound (A)on oxidation with dilute chromic acid gives an unstable compound (E)which decarboxylates readily to give (F), C H O. The compound (F) gives a hydrocarbon (G) on

3 6

treatment withamalgamated ZnandHCl. Givestructures of (A) to (G)with proper reasoning.

Apleasant smelling optically active ester (F) has M.W. = 186. It does not react with Br in CCl .Q.25 2 4Hydrolysis of (F) gives two optically active compounds, (G) soluble inNaOH and (H). (H) gives a

positive iodoformtest and on warming with conc. H SO gives (I) (Saytzeff-product) with nogeometri-2 4

cal isomers. (H)on treatment with benzene sulfonyl chloride gives (J), which on treatment with NaBr gives optically active (K). When theAg + salt of (G) is treated with Br racemic (K) is formed. Give2structuresof (F) to (K) and explain your choices.

Q.26 Compound(A), M.FC H O reduces ammoniacal silver nitrate to metallic silver andloses its optical6 12 2activity on strong heating yielding (B), C H O which readily reacts with dilute KMnO . (A) onoxida-6 10 4tionwith KMnO gives (C)having M.FC H O which decarboxylates readily on heating to 3-pentanone.4 6 10 3The compound (A) can be synthesized from a carbonyl compound havingM.F. C H Oon treatment3 6with dilute NaOH. Oxidationof (B)with ammonical silver nitrate followed byacidification gives (D). (D)forms a derivative (E) withSOCl which on reaction with H CNHCH CH yields (F). Identify (A) to2 3 2 3(F) giving proper reaction sequences. What is the name of the reaction involved in the conversion of C H O to (A)? Give the IUPACnomenclature of compounds(A) to (F).

3 6

Asolidorganiccompound (A), C H O is insoluble indilute NaHCO . It produces a dibromoderivativeQ.27 9 6 2 3(B), C H O Br on treatment with Br /CS . Prolongedboilingof (A) with concentrated KOH solution9 6 2 2 2 2followed byacidification gives a compound (C), C H O . Thecompound (C)giveseffervescence with9 8 3aqueousNaHCO . Treatment of (C) withequimolar amount of Me SO /NaOH gives (D), C H O .3 2 4 10 10 3The compound (D) is identical with the compound prepared from ortho-methoxy benzaldehyde bycondensation with acetic anhydride in the presence of sodium acetate. Treatment of (C) with alkalineC H SO Clproduces (E) whichon vigorous oxidation with KMnO gives (F). Hydrolysis of (F) gives6 5 2 4a steamvolatile compound(G) havingM.F. C H O . Give thestructuresof(A) to (G) giving theproper 7 6 3reaction sequences.

Q.28 Aneutral compound (A) C H O on refluxingwith dilute alkali followed byacidification yields (B)9 16 2C H O and (C) C H O. (B) liberates CO from bicarbonate solution. (C) on dehydration yields5 8 2 4 10 22-buteneas themajor product. B on treatment with OsO followed byreactive hydrolysis gives (D)4C H O (D)when treated with leadtetraacetate furnishes acetone and (E) C H O . (E) isacidic and5 10 4. 2 2 3reducesTollens reagent. Identify (A), (B), (C), (D)and (E) and write the reactions involved.

Anorganic compoundAon treatment with ethyl alcohol gives a carboxylic acid B and compound C.Hydrolysis of C under acidic conditionsgives B and D. OxidationofD with KMnO alsogives B. The

Q.29

4compound B onheating with Ca(OH) gives E (molecular formula C H O). E doesnot giveTollens test2 3 6and doesnot reduce Fehlings solutionbut forms a 2, 4-dinitrophenylhydrazone. IdentifyA, B, C, DandE.

Anaqueous alcoholic solution ofacetoacetic ester imparts a blue colour with a solution ofFeCl .To thisQ.30 3solution ifbromine solution is added carefully, the initial colour disappears and the brown colour of

bromine appears,which fades soonand thesolution after remaining colourless for some time regainsthe blueviolet colour. Explain.

28


29/52


EtO H3O Zn(Hg) (X)Q.1 HCl

Product (X)ofabovereaction is:

(A) (B) (C) (D)

Q.2 Correct order of reactivity of following acid derivatives is

MeCOClI MeCON3 MeCOOCOMeIII

(C) I > III > IIII

(A) I > II > III (B) II > I > III (D) II > III > I

H3O N aO EtI

EtOH

Q.3 CH (COOEt) + (CH ) Br II2II is:

2 2 3 2

(A) (B) (C) (D)

Q.4 Find thereagent used to bringabout following conversions.

(A) ClCOCH 2 CH2 COCl(C) CH3 COCl

(B) CH3COOCOCH3(D) ClCO COCl

( i) C H 2 N 2 ( 4 m o le ) (A), Product (A) of reaction is ?Q.5(ii)Ag 2O; / MeOH

(A) (B)

(C) (D)

29

EXERCISE-III


30/52


Q.6 X.X will be

(A) (B) (C) (D) None

O|| 18 dil.H SOQ.7 Me3C C O CMe3 2 4

Product of this reaction and themechanism is:

O 18O||(A) Me3C C OH

O||

(C) Me3C C OH

Guess theproduct

||Me3C C OH

O

18+ Me3C OH , A 1AC (B) + Me3COH, A 1AL

||18+ Me3C OH ,

18A 2AC A 2AL(D) Me3C C OH + Me3COH,

Q.8PClCH3CH2CONH2

(A) CH3CH2 CN

5 ?

(B) CH3CH2COCl (C) CH3CCl2CONH2 (D) CH3CH2CONHCl

Q.9 Endproduct dueto hydrolysis of (A) and subsequent heating is

(A) (B) (C) (D)

O||

Q.10 N aO H Q, Q is?

Me C O CH CH NH2 2 3

O||

(B) Me C NH CH 2 CH 2 OHO||

Me C O CH2 CH 2 NH2(A)

(C) (D) MeCOONa + HOCH 2CH2 NH2

30


31/52


(i)LAH

(Y) ( i i )H 3O (Z)(iii)dilOH

S OC l2Q.11 4-Pentenoicacid (X)

Identifyfinal (major) product:

O||(A) CH 2 CH CH 2 CH 2 C

N

OH

(B) CH2=CHCH 2 CH2 CH2 N

|CH 2 CH 2 CH 2 CH 2 CH

N(C) (D) CH3 CH2 CH2 CH2 CH2 OH

O O|| ||

Q.12 H2 N C CH 2 CH 2 C N3

P; P is

(A) (B) (C) (D)

N aN O2 (S)HCl

H 2O (R)(P) A g 2O (Q)Q.13 N a N3

Identify (S)major product:

(A) (B) (C) (D)

Q.14 Which of the following given two alcohol when it reacts withLiAlH4. O OO

||CH3 C O CH3

O||

CH3 CH C O CH 2 CH3|CH3

|| ||(A) (B) CH 3 C O C CH 2 CH3

(C) (D)All

Q.15 In which of following reaction CO 2 gas will beevolved. O OCO2H || ||

CO2H (A) (B) Ph C CH C OH 2CO2H

N aH C O3(C) (D)All

31


32/52


33/52


O||C NH 2

Product is:

O

(i)CH MgBr ( i) I2 C a(O H )2(ii)

P O 2 5 A 3 B

(ii)H3O

Q.20 C

O||C OH

||C CH3(A) (B)

C CH 2CH 3||O

(C) C||O

(D)

Q.21

A ( i) I2 O H B B r 2 H 2O C(ii)H3O

'C' form white precipitate compound 'C'is:

(A) (B) (C) (D)

Q.22 Which of thefollowing esters cannot undergo selfclaisen condensation(A) CH3CH2CH2CH2CO2C2H5(C) C6H5CH2CO2C2H5

18

(B) C6H5CO2C2H5(D) CH3CH2CO2C2H5

c onc .H 2 SO 4OHQ.23 P.+COOH

18CO

O

CO

O(A) (B)

18CO

O

CO

O(C) (D)

Q.24 Method to distinguished RNH 2 & R 2 NH(A) NaNO 2 / HCl(C) Hinsberg test

(B)Hoffmann'smusturd oilreaction(D)All of the above

33


34/52


O

I 2 , N aH CO 3OHQ.25 Product.

Major Product isI

I OIO O(A) (B) OH

IOI OIO(C) (D) ONa

Q.26 Which molecule will give the following dicarboxylic acid onheating with acidic solution of KMnO 4?

O

||O

CH2COOHHOOC

(A) (B) (C) (D)

OO O ( i ) H / H 2O

(ii)O OQ.27 Product:

OO

O OO O COOHCOOH(A) (B) (C) (D)

COOH COOH

A lC l3 [X]H / H2O

Q.28 + Z n / Hg / H Cl [Y] H F [Z].The structure of [Z] is

(A) (B) (C) (D) none

34


35/52


Q.29 + P (Product). Pis:

(A) (B) (C) (D)

Q.30 Which will elimination CO 2 only onheating

(A) Me C CH2 COOH(B) Ph C CH2 SO2H

||O

||O

OHCOOH

(C) (D) CH 2 = CHCH 2 COOH

Q.31 Methanoic acid and Ethanoic acid canbe differentiated by:(A) Fehling test (B) Iodoformtest

Assertion and Reason :

(C)Shiff's test (D) NaHCO 3 test

Q.32 Statement-1 : is optically inactive, it is taken ina glass container and plane polarized light

(PPL)is passed through itafter heating it for several minutes. The PPLshows significant optical rotation.

Statement-2 : Like -keto acid, gem dicarboxylic acid eliminates CO 2 on heating.(A)Statement-1 is true, statement-2 is trueandstatement-2 iscorrect explanation forstatement-1.(B)Statement-1 istrue, statement-2 istrue andstatement-2 isNOT thecorrect explanationfor statement-1. (C) Statement-1 is true, statement-2 is false.(D)Statement-1 isfalse, statement-2 is true.

Comprehension 1:

An unknown compound having molecular formula C 8H4O2Cl2 cangivefollowingset of reactions.C8H4O2Cl2

AC8H4O2Cl2

B

MgX N H 3 (C H O N) C8H6O4C

C H O N R M gX8 5 2D

8 4 2E

CH5 NG

+ C8H6O4C

H O

C9H7O2 NF 3

35


36/52

Carboxylic Acid & It's DerivativesQ.33 What could bethestructure ofA:

(A) (B) (C) (D)

Q.34 What could be the structure ofB

(A) (B) (C) (D)

Q.35 Structure of D is(stable one)

(A) (B) (C) (D)

Comprehension 2 :Ozonolysis of a compoundAgathene dicarboxylic acidgives following compounds:

HCHO, CHO|COOH

&

On complete Reaction by Na-EtOHAgathene dicarboxylic acid give hydrocarbon C 20H38 which have5 chiral carbon in it.

Q.36 The structure ofAgathene dicarboxylic acid is

(A) (B)

(C) (D)

36


37/52

Carboxylic Acid & It's DerivativesQ.37 How manychiralcarbon are present inAgathene dicarboxylic acid:

(A) 2 (B) 3 (C) 4 (D) 5

Q.38 Total stereoisomers possible forAgathene dicarboxylic acid are:(A) 16 (B) 18 (C) 32 (D) 64

Q.39 Structureof product formed whenAgathene dicarboxylic acid isheated with sodalimeis:

(A) (B) (C) (D)

Comprehension 3 :

18OMe

( i ) O3 A + B OH/(ii) H2O /Zn+

H / H2O EC + D +H /

F

Q.40 Product C and D are

O O|| ||

O O|| || 18

(A) H C C OHO O|| ||

H C C OH

+ MeOH (B) H C C OHO O

+ MeOH

|| ||HO C C OH

18+ MeOH

18+ MeOH(C) (D)

Q.41 Mechanism for hydrolysis ofAwill be

(A) A (B) (C) (D) A 2ALA A2 1 1AC AL ACQ.42 F is

(A) (B) H C C OH|| ||

H C CH C CH|| | || ||

O OO OH O O

OO

O(C) (D) C

OO

O

37


38/52

Carboxylic Acid & It's DerivativesComprehension 4 :

O||

H C O CH CH2

KOH H 3O A+B

?

MnO

Red KOHC ?

Q.43 Mechanism offormation ofAandB is

(A) A 2AC (B) A 1AC (C) (D) A 2ALA 1ALQ.44 Select true statement:

(A) BothB and C give same name reaction with KOH (B) BothB and C give iodoformtest(C) Both B and C give chiral product with PhMgCl followed by NH 4Cl(D) BothB and C are redox reactionBest method out of the given to prepare B isQ.45

O||

H C Cl M e2 Cd

O

O||

H C Cl

O

M eM g Br (A) (B)

||(D) H C OMe M e 2 Cd

||H C OMe M eM g Cl(C)

Match the Column :Q.46 Match reactions given in column I with names in II.

Column I

COOEt

ColumnII

(A) E tO Na

O(P) Knovenagel reaction

COOEt ( i) E tO K

(ii) H O ,(B) CH2(COOEt) 2 +Br

(Q) Perkin reaction3

O ( i) Zn(C) O (R) Reformatskyrecation

(ii)H3OO

OMeO(D) M eO K (S) Dieckmann's condensationOEt

OColumn IQ.47 Column II

(Product differentiate by)

O3Zn

(A) CH3 CH=CH2CH3

(U) + (V) (P) ByHaloform test

|CH3 C CH CH3

O

O3(B) (W) + (X) (Q) ByFehling test Zn

||Ph C O Ph (C) H 3O (Y) + (Z) (R)(S)

By aq. NaHCO 3ByTollenTest

38


39/52


Q.48 (Reactions)CH3 CH = CH 2 + HCl

CN

(Type of reaction)Regioselective(A) (P)

(B) (Q) Stereoselective+

CN

H ClCH2D(C) (R) Stereospecific

H

HCl (D) (S) DiastereomersCH2CMe3

H

(T) Cyclic addition

ColumnIIQ.49 Column I

( i) A l(O Et) 3 ,(ii)H3O

(A) CH 3 C H Products (P) Oneofthe organic product||O formed will decolourise

bromine water COOMe

( i) M eO (ii)H3O /

CH + CH2(B) Product(s) (Q) One ofthe organic productCOOMeO

formed willgive brisk effervescence withNaHCO 3

One ofthe organic product(C) PhMgCl ( i) C O2 Products(ii)H(iii) SOCl2(iv) MeMgCl

(R)

formed willgive haloformtest.One ofthe organic productformed will give2,4DNPtest

(S)

Q.50 (Reaction)

R C OR'||O

(Product obtained by reaction)

( i) L A H(ii)H 2O

(A) (P) R'CH 3

(i)LAH (ii)H 2O

(B) R ' C OH||O

R'CH2 Br

(Q) R'OH

(C)

(D)

L A H (R)(S)

R'CH2 OH

R'HR ' C H||O

S BH / E tO H

(E) R C OR'||O

R e d P / HI (T) RCH3

39


40/52


ANSWER KEY EXERCISE -I

Q.1 The uptakeof2 H atoms shows the presence ofone>C= C


41/52

Carboxylic Acid & It's DerivativesQ.8 It is because carboxylic group doesnot havea true carbonyl group due to resonance.

OO

R C O H R C OHDue to resonance >C= O bond of COOH develops partial doublebond character and cannot show

reactions with hydroxylamine, phenyl hydrazine, etc.It is because formic acid combines theproperties of bothan aldehyde and anacid.Q.9

Aldehyde

H COH

Hence it hasreducing character of aldehydes.HCOOH 2[Ag(NH 3 )2 ] OH HCOONH 4 3NH 3 H 2O 2Ag

or HCOOH Ag 2O CO 2 H 2O 2Ag Q.10 Both these unsaturated acids have two ionisable hydogens.After the release of first hydrogen, second

hydrogen ofmaleiate ionis involved inH-bonding, whereas noH-bonding ispossibleinfumarate ion.

O HO

CO

H C CO

HCH-bond OH

H C C OH

O(Maleiate ion)

O(Fumarate ion)

(H-bond not possible)

Due to the formation of H-bond in maleiate ion more enegy is required to remove H fromit than fromfumarate ion, inwhich H release is easycomparatively. Thus,K 2 for fumaric acid ismore than maleicacid.

OCH3 CH2 MgBr H 2C CH2Q.11

OHCH3 CH2 CH2CH2 O MgBr 3 (X)CH3 CH2 CH2CH2 OH(Y)CH3CH2 CH2COOH(Z) Butanoic acid

K Mn O 4

41

O


42/52


43/52

Carboxylic Acid & It's DerivativesQ.19 Dehydration occur with all the three reagent

C6H5CH2CONH2 P 2 O5 C H CH CN + H O6 5 2 2C H CH CONH C6H5CH2CN + 2HCl + SO 2SOCl2 26 5 2

P OC l3 Or C6H5CH2CONH2 C H CH CN+H O6 5 2 2PCl5Q.20 Themechanismofesterification

OH|

R'O H R C OHOH|H + R C OH 2|

OR'Slow

O||

R C OR'

O||

R C OR'H H 2O

As the size ofthe substituent on carbon increases, the tetrahedral bonded intermediate becomemore crowded.The greater the crowding the slower is the r reaction(A) (CH CO) O (Acetic anhydride)Q.21 3 2(B) CH COOH (Ethanoic acid)3(C) CH COOC H (Ethyl ethanoate)3 2 5(D)C H OH (Ethanol)3 5(E) CH COCH3 3

Q.22 (A) CH CH COOC H (Ethyl propanonate)3 2 2 5(B) CH3.CH2.CO.CH.COOC 2H5 (Ethyl (2-methyl, 3-ketopentanoate)

CH3

(C) CH3.CH2.CO.CH.COOC 2H5 (2-methyl, 3-ketopentanoic acid)

CH3

Q.23 (A) CH .CH .CH .CH COOCH .CH or CH COOCH CH CH CH3 2 2 2(B) C H OH

2 3 3 2 2 2 3

2 5

(C) CH .CH .CH .CH OH3 2 2 2(D) CH CHO3(E) CH CH==CH.CHO3(F) CH COOH3

CH3 CCOOHQ.24 (A) CH3 CCOOH

CH3 CHCis

HCCH3Trans

H

(B) CH3.CH2.C*COOH (2-methylbutanoic acid)CH3

Q.25 (A) HCOOH (B) CO (C) COOH.COOH

43


44/52

Carboxylic Acid & It's DerivativesQ.26 A

BCDE

=====

CH OH (Methanol)(Methyl ethanoate)(Methanal)(Methanoic acid)(Formamide or methanamide)

3

CH COCH3HCHOHCOOHHCONH

3

2

Q.27

OH

Q.28 A = B = H2C OHO OH

CH3CH3 O

D = H2C NC = H2C ClCH3

OO

E = H3C OH F = H3C CH3

OO O

G = H3C CH3

Q.29

H3CH3C

O OQ.30 X = H3C Y=CH3HO

propionic acidO propyl propionate

H3CH3C

Z = D = CH2OH propan-1-ol H3C

44


45/52


EXERCISE - II Q.1 (a) The isomers have 1of unsaturation that must be due to COOH,since CO isevolved on2

adding NaHCO . The remaining oxygen may be present asOHor OR.3

COOH COOHCH2COOH COOH

H3C CHCH2OH

H3C CHOCH3

(G)

H3C CHOH

(E)

H2CH3C CHOH

(D) (F)

(b) LiAlH converts COOHto CH OH. Only(D) is reduced to anachiral product.4 2

Not chiral

COOH CH2 OH

H C CHH3C CH L iAlH 4 3

HO(D)

HO

(c) The ether (G) differs from(E)and (F) in that it is inert to oxidation by KMnO or CrO . (E)gives a4 3 positive iodoformtest.

CH3 CH3 CH3CH3CO2Cl H3CEther

Mg C MgCl H3C H3CPeroxideHCl C C COOMgClH3C CQ.2

CH3CH2 CH3 CH3

CH3

H2 O / H H3C C COOH Mg (OH )ClCH3

COH C C H CH MgBr H C CMgBr 2 H C C.COOMgBr Q.3 3 CH 4 (G) (H)

H H C CCOOH H gSO 4 / H 2SO 4 H C C COOH T auto mer ism H2O(I )

OH H

COOH

K Mn O4 H2CH C CH2 COOH (O )COOH

O (J)

O

C OCH CHQ.4 CH H 2O CH CH COOH CH CH CH OHCH CH3 2 2 2 3 H 3 2(A )

3 2 2(B )

OH C hro mic a cid CH

CH CHO ( O ) CH CH COOHCH CH CH3 2 2 (O) 3 2 3 2(A )

45


46/52

Carboxylic Acid & It's DerivativesSOCl2 NaN3 D HYdrolysisQ.5

Q.6

RCO 2H RCOCl RCON 3 RNCO RNH 2 bond is very stable due to large Hf of CO; so the decomposition reactionC O

O

H C Cl C O HCl is favoured. Formly chloride is not stable above 60C.Q.7 Anextremelymild but selective oxidizing agent foraldehydes issilver oxide suspended inaqueous base.Anunsaturated acid isobtained with this reagent because the>C=CC= O group because ofresonance stabilization.Q.12Theresonance takeplace as follows.

Q.13 CH3COOH(X)Acetic acid

CH 3

(CH3COO)2 Ca(Y)

Cal. acetate

C a( O H ) 2

d rydistillati on

C = O Conc. H SO 2 4CH3Acetone

CH 3

CH3

(Z) Mesitylene

CH3

[o]Q.14 CH3CH2COOH CH CO COOH+H O3 2SeO2Propionic acid Pyruvic acid

46


47/52

Carboxylic Acid & It's DerivativesQ.15 Acidaredirectlyreducedto the corresponding primaryalcohol with powerful reactant like LiAlH 4. It

attack only on the carbonyl groupofa fatty acid.O||

R C OH+4H L iAl H 4 RCH2OH + H2O

AlkanolCH3|

CHO

CH||CH

2 2H g / H 2S O 4(x )

H

/ Cr 2 O 7(Y)

Q.16

AcetyleneCH3

N aO HCaO

||COOH

CH4

Ethanoic acid Methane

CH3CN 3 CH3COOHOH NHQ.17 3Ethane nitrile

(X)CH3COONH4

Ethanoic acid

(Y) CH3CONH2

Ammoniumethanoate EthanamideBr 2 /KOH CH NH 3 2

Amino methaneQ.18 CH3COONa

(Z) PCl 5

CH3COOH N aOH (X)

CH3COCl(Y)

CH3COCl(Y)

O

+ CH3COONa(Z)

O

O|| || ||CH3 C O C CH3 2CH3 C Cl

(E)(a) CH3Cl

(Y)Q.19 CH3COCl

Methyl chloride Acetyl chloride

CH3Cl M g CH3MgCl

Methyl chloride

CO 2

H2O / H

CH3COOH CH3COCl S OC l 2Acetyl chlorideCH3CONH2(b) C2H5OH

Ethyl alcohol Acetamide[O] CHCH3OH + CHO

[ O]3K 2Cr 2 O7 / HMethyl alcoholCH3COOH CH3COCl

S OC l 2

CH3CONH2 Acetamide N H3

47


48/52


(c) CH3COOHAcetic acidCH3COOHAcetic acid

CH3COOC2H5Ethyl acetate

CH3CH2OH LiA IH 4

3

CH

3COOC

2H

5Ethyl acetate

O

CH COOH / H

|| NHH CH3CH 2 OC

CH2+O = CQ.20 (a) NHH CH 3 CH2 OC||O

(X)Urea

O||

NH C

P C l3 O =C

(Y)

CH2+2C2 H5OH

NH C||O

(Z) Ethanol

NHH C2H 5 O C = O|+

C H = O C = O(b) O = C 2 5 NHH

Urea (E) Diethyl oxalate NH C = O

| NH C = O

P C l 3 O =C

+ 2C2H5OH

(F) Parabanic acid(Oxalyl urea)

NH2 H Cl(c) CH2=O + O = C NH2

Formaldehyde (X) Urea

CH2 (OH) NH CONH 2 C H 2 OMonomethylol urea

CH2(OH)NHCONH (OH) CH 2 U rea ResinDimethylol urea ureaformaldehyde

(i) CH CH CH CH Br CN CH CH CH CH CN

Q.21 3 2 2 2 Br 3 2 2 2

2 HO H / H CH CH CH CH COOH3 2 2 2n Pen tanoic acid

CH3 CH3CH3

(ii) H3C C Br

H2SO4 H CMR 3 CN H C C HSO 4 H OH C HCN 3 Br

CH3 CH3CH2

48


49/52


CH3 CH3CH3 CH3

H3C C OH S OCl 2 Ether Mg MgCl (i) C O2 H3C C COOHH C C Cl H C C3 3 (ii) H O3

CH3 CH3CH3 CH3

HH

HOOCCH2

HOOCCH2

HOOCCH 2

HOOCCH 2

Br Q.22 2 H CH2C 2 NiBr

HF

Meso compound

HE

Meso compound

CH3 CH 3and

CH 3 COOHC = C C = C

Q.23 H COOH H CH3

(A) Geometrical isomers

CH3 CH3

C2H5 CCOOH HOOCCC 2H5or

H H

B

Q.24 (A) CH CHOHCH COOH (B) CH CH=CHCOOH3 2 3(D) CH CH = HCON(CH )(C) CH CH = CHCOCl3

(E) CH COCH COOH3

(F) CH COCH3 2

3 2 3 3(G) CH CH CH3 2 3

Q.25 is a saturatedmonoester with M.W = 186

CH3 O CH3 CH3 O

CH3 HH3C OF = G = H3C O

CH3 CH3 CH3OH

CH3H = H3C I =

CH3

OSO2C6H5 Br

CH3

CH3H3C H3CJ = K =

CH3 CH3

49


50/52


CH3CH3O

Q.26 A= H3C B = OH3C

OH

CH3 CH3

O OH3C H H3C HC = D =

O O O

CH3 CH3CH3

NClH3CE = H3C F =

O CH3O

Q.27

CH3CH3Q.28 A C = CHCOCHCH 2CH3 ;or C = CHCOCH 2CH2CH2CH3

O H3CCH3 O CH3

CH3

H3C

CH3CHCH2CH3OH

CH3CH2CH2CH2OH ;

DehydrationB C = CHCO 2H ; C

2 - Butene

CH3

H3C

D O=CHCO 2H

MF : C2H2O3CCHCO 2H ; E

OH OHM.F C5H10O4

50


51/52

Carboxylic Acid & It's DerivativesQ.29 The given reactions are as follows.

C 2H 5O H B A + C(Carboxylic acid)

H BC + D

KMnO 4

Ca( OH )2 C HO

B 3 6(E)

The compound E must beketonic compound as it doesnot give Tollens test and does not rceFehlings solutionbut formsa 2, 4-dinitrophenyl-hydrazone. Therefore, its structurewould beCH COCH

3 3(acetone).Since E isobtained byheating B with Ca(OH) , the compound B must be CH COOH(acetic acid).2 3Since B is obtained byoxidation ofD with KMnO, the compound D must beanalcohol with molecular 4

formula CH CH OH (ethanol).3 2Since B and D are obtained byacid hydrolysis of C, thecompoundC must be anester CH COOC H3 2 5(ethyl acetate).Since thecompounds B (acetic acid) and C (ethyl acetate) are obtained bytreatingAwith ethanol, thecompoundAmust be an anhydride (CH CO) O (acetic anhydride).

3 2Thegiven reactionsare

(CH 3CO)2O C 2 H 5 O H ` CH3COOH + CH 3COOC 2H5acetic anhydride

(A)acetic acid

(B)ethyl acetate

(C)

H+

CH3COCH 3acetone

(E)

CH3C OOH + C 2H5OHeth anol

(D)acetic acid

(B)KMnO 4

Q.30 Acetoacetic ester shows tautomerism and the two forms arecalled as keto and enol forms.OH OO O

C2H5C2H5 H3C OH3C O

Keto form Enol form

OH

)gives blue-violet colour with FeCl 3 solution. When Br 2 is added,

of the enol form.

The enol (H3C C CH

it reacts at once with

Br OH O HO

C2H5C2H5 Br 2 O

H3C O H3CBr O

51

Ca(OH) 2


52/52

Carboxylic Acid & It's DerivativesAssoonasenol formisconsumed, its colouration with FeCl disappearsand excessofbromine gives3

browncolour.Asketoand enol formsareinequilibrium, whenenolformisused, theequilibriumshifts toright handside to give moreenol formwhichdischarges thecolourofexcessofBr and gives blue violet2colour withexcessof FeCl present inthe reaction mixture.3

EXERCISE - III Q.1Q.8

Q.15Q.22Q.29Q.36Q.43Q.46Q.48Q.50

BA

DBAAA

Q.2Q.9

Q.16Q.23Q.30Q.37Q.44

AB

BBA,C,DCD

Q.3Q.10

Q.17Q.24Q.31Q.38Q.45

DB

ADA,CCB

Q.4Q.11

Q.18Q.25Q.32Q.39

DB

BADA

Q.5Q.12

Q.19Q.26Q.33Q.40

BC

CDCC

Q.6Q.13

Q.20Q.27Q.34Q.41

CB

CCCA

Q.7Q.14

Q.21Q.28Q.35Q.42

BD

CDBD

(A) S, (B) P, (C) R, (D) S(A) P, (B) Q,R,T(C) P,S (D) P,Q,S(A) QR(B) R (C) P (D)R (E) ST

Q.47Q. 49

(A) P, (B) Q,S (C) R (A) Q,R (B) P,Q (C) R,S

carboxylic acid and its derivative

Documents