AROMATIC
COMPOUNDS
CONTENTS
EXERCISE - I
EXERCISE - II
EXRECISE - III
EXRECISE - IV(A)
EXRECISE - IV(B)
ANSWER KEY
ORGANIC CHEMISTRY

Exercise -I
Q1. + CHCl3
+ KOH  + B
un ected product
exp
What areA& B?Explainwithmechanism.
Q2. PhCH2
MgCl + MeCHO  PhCH2
CHOH Me + A
Aisanisomer oftheother product &undergoesthe haloformreactionto give o-toluic acid. What isA?
Suggest a mechanismfor its formation.
Q3. 2, 4 dinitrophenyldiazonium ion couple with PhOMe whereas 2, 4, 6 compound couple with 2, 4, 6
trimethylbenzene. (mesitylene). Explain.
Q4. Ifthere iskinectic isotope effect what willhappenwhen
(a) C6
H6
& C6
D6
are allowed to react separatelybut under identicalcondition with E+
.
(b) a 50 : 50 mixture ofC6
H6
& C6
D6
is allowed to react with a limited amount ofreagent.
(c)Anisole & 4D anisole are allowed to react with E+
separately.
Q5.
EtOH
H
 


 A
1
2
.
.
NaH
MeI
 

 B
1
2
.
.
NaOH
H
 

 C
1
2
2
3
.
.
SOCl
AlCl
 
 D
What areAto D?
Q6. The following diacid undergo intramolecular FridelCraft acylationwith
concentrated H2
SO4
to givetwo products. Give their structures withproper mechanism.
Q7. Mesitylene + HF + BF3
 Ayellow colored compound (A) where mesitylene : HF : BF3
=1 : 1 : 1.
Give proper reasoning.
Q8. What isthe attacking site ofdiazocoupling of
(i) napthol (ii)  napthol (iii)resorcinol.
Q9. Account forthefollowingfacts
(a) whyPhNO2
acting as suitable solvent inFridelCarftAlkylation.
(b) The diazo coupling ofphenolis carried out at pH = 9.
(c) Biphenylis more reactive thanbenzene towards EAS.
Q10. The nitrationoffuranwithacetylnitrateproceeds via 2,5additionintermediate withthereagent.Suggest
a plausible mechanismfor this product formation.

Q11. HClO4
 

 Product. What type ofreaction it is? Give proper mechanism.
Q12. when reacts with NO BF
 
2 4 two products & are formed with
44% &56% respectively whereas whentreated with NO BF
 
2 4 onlyone product
is formed as sole product. The structure ofthe products givenas follows .
Q13. IodinationofPhenol& 2, 4, 6 trideuterophenolwhencarried out separatelyKH
/KD
ratio is found to be
4. Explain.
Q14. No reaction furan
 

 CH2
O +
What areA&B? What explanationcanyougive forunreactivityoffuranw.r.t. reagents ascomparedto
2 Me-furan & pyrrole.
Q15.
AcCl
AlCl
 


3
A AcCl AlCl

 

3 B (disubstituted product)
(monosubstituted
product)
What areA& B? Explainwith reason.
Q16. Kolbe Schmidt reaction if carried out in presence of soidum phenoxide product will be exclusively
sodium ohydroxy benzoate whereas if reaction is carried out in presenceofK+
OPh–
, salt of p acid
becomes majorproduct. Explain.
Q17. Heating acetone with an excess of phenol in presence of HCl produces bisphenolA (C15
H16
O2
) &
reactioninvolvedinitsformationare similarto thoseinvolvedinsynthesis ofDDT. Explainstructure ofA
withmechanism.
Q18. Whenamixture ofN chloro 2, 4 dichloro acetanilide & anisole is dissolved inHClamongthe products
isolated are o & p chloroanisole . Discuss.

Q19. What are the products inthefollowing reaction?
+ (AcO)2
Hg NaOH
 

 A NaCl
 

 B.
What are A & B?
Q20. What are the products inthefollowing reaction?
(a) + MeCO2
H ZnCl2
 

 (b) + NaNO2

 


HCl
(c) Aq NaHCO
. 3
 

 A
A Br
AcOH
2
 
 B Boil in
H O
 

2
C
Exercise - II
Q1. Write anequation for the formationformH2
SO4
ofeachofthe followingsulfonating eletrophiles.
(a) H3
SO4
+
(b) HSO3
+
(c) H2
S2
O7
Q2. When phenol is treated with D2
SO4
in D2
O there is formed phenolcontaining D instead ofH at o & p
to the –OH group. Benzene undergo similar exchange but at a muchlower rate;under same conditions
PhSO3
H does not undergo exchange at all.
(a) Outline aplausible mechanismfor H–D exchangein aromatic compounds.
(b) What is the attacking reagents in each case.
Q3. Outlines alikelymechanismfor thefollowing reaction.
PhCMe3
+ Br2
(AlBr3
)  PhBr + HBr + Me2
C = CH2
Q4. Treatment of sulfanilic acid (p NH2
C6
H4
SO3
H) with 3 moles of Br2
yields 2, 4, 6 tribromo aniline-
explain.
Q5. Resorcinal when reacts with PhthalicAnhydride in presence ofH2
SO4
what will be product? Explain
withmechanism.
Q6. Benzene, toluene, xylenes (o, m, p) &mesitylenes dissolved inHBF4
to formsalts. Explain the order of
basicitymesitylene > mxylene > o & p xylene > toluene > benzene.
Q7. Synthesize butter yellow from Benzene & N, N dimethyl aniline. Structure is given below.
Ph – N = N – – NMe2
.
Q8. Synthesize orangeII fromBenzene usinganyother reagent. Structureis givenbelow.

Q9. What willbethe products inthefollowing reaction ?
(i) COCl2
+ 2 equivalent of PhNMe2
 (ii) + 2ICl 
(iii) + NaNO2
+ HCl  (iv) + Br2

(v) + 2ICl  (vi) HNO3
 


Q10. What willbe the products inthe following reaction
(i) + Ac2
O AlCl3
 

 (ii) + Br2

(iii)ArH + SO2
Cl2
AlCl3
 

 (iv) + Cl SO3
H 
(v) PhNH2
+ PhSO2
Cl  ? NaOH
Me SO
 


 2 4
? H O
3

 

 ?
(vi) + HCl + HCN
AlCl
H O
3
2
 


Q11. Synthesize
(i) NapthalenefromBenzene (ii)AnthracenefromBenzene (iii)  tetralonefromBenzene
Q12. Synthesize
(a) fromPhOMe (b) from PhOMe
Q13. Conversion
(i) (ii)
(iii)
(iv) o hydroxyacetophenone  2, 5 dihydroxyacetophenone

Q14. Conversion
(i)  (ii) 
Q15. Convert
(i) PhNH2
 1, 3, 5 tribromobenzene (ii) PhH 2, 4, 6 tribromo 1, nitrobenzene
(iii) Nitrobenzene Pentabromobenzene
Q16. Conversion
(i)  (ii)  (iii) 
(iv)  (v) 
(vi) Benzene trinitrostilbenewiththe help of benzaldehyde formation.
Q17. Conversion
(i)  (ii) 
(iii)  (iv)  (v) 
Q18. (i)  (ii) 
(iii)  (iv)  (v) 

Q19. Conversion
(i)  (ii) 
(iii)  (iv)  (v) 
Q20. Conversion
(i) 
(ii) 
(iii) 
(iv) Benzene  m cresol
(v) Benzene  m- iodophenol
(vi) Benzene  3, 4, 5 tribromophenol
Exercise - III
Q.1 Whichofthe followingstructures correspond to the product expected, whenexcess ofC6H6 reactswith
CH2Cl2 in presence ofanhydrousAlCl3:
(A) (B)
(C) (D)
Q.2 Inthesulphonation,acetylationandformylationofbenzene the groupofeffectiveelectrophileswould be:
(A) O
C
H
,
O
CH
,
SO 3
3



 (B) O
C
H
,
O
C
CH
,
SO 3
3




(C) SO3, CH3CHO, CO + HCl (D) HSO3, CH3CO, HCO
Q.3 In the reactionofp-chlorotoluene with KNH2 inliquid NH3, the major product is:
(A)o-Toluidine (B)m-Toluidine (C) p-Toluidine (D) p-Chloroaniline

Q.4 Anaromaticcompound 'A'C7H6Cl2, givesAgClonbonding withalcoholicAgNO3 solution, and yields
C7H7OClontreatment withsodiumhydroxide. 'A'onoxidationgives a mono chlorobenzoic acid which
affords onlyone mononitro derivative. ThecompoundAis:
(A) (B) (C) (D)
Q.5 Benzyne intermediate isnot observed in:
(A) (B) (C) (D)
Q.6 

 
 2
NaNH
A, major productAand reaction R are:
(A) , eliminationaddition (B) , eliminationaddition
(C) , cine substitution (D) , additionelimination
Q.7 Chloral+ Cl 


 
 4
2SO
H
.
Conc product. The product is:
(A) Lindane (B) DDT (C)Tefflon (D)Ethaneperchlorate
Q.8 The reaction ofbenzene with CO and HClinthe presence ofanhydrousAlCl3 gives:
(A) Chlorobenzene (B)Toluene (C) Benzylchloride (D) Benzaldehyde
Q.9 The highest yieldofm-product is possiblebythe electrophilic substitutionofthe following:
(A) C6H5CH3 (B) C6H5CH2COOC2H5
(C) C6H5CH(COOC2H5)2 (D) C6H5C(COOC2H5)3
Q.10 Benzeneonreactionwith'A'forms whichonreactionwith'B'forms
'A' and 'B' are:
(A) Zn(Hg) + conc. HCl, (B) , LiAlH4
(C) , NaBH4 (D) , Zn(Hg) + conc. HCl

Q.11 Fortheelectrophilicsubstitutionreactioninvolvingnitration,whichofthefollowingsequenceregarding
the rate ofreactionis true?
(A) 6
6H
C
k > 6
6D
C
k >
6
6T
C
k (B) 6
6H
C
k < 6
6D
C
k <
6
6T
C
k
(C)
6
6H
C
k =
6
6D
C
k =
6
6T
C
k (D)
6
6H
C
k >
6
6D
C
k <
6
6T
C
k
Q.12 For theelectrophilic substitutionreactioninvolvingsulphonation, whichofthefollowingsequence
regarding the rateofreactionis true?
(A) 6
6H
C
k > 6
6D
C
k >
6
6T
C
k (B) 6
6H
C
k < 6
6D
C
k <
6
6T
C
k
(C) 6
6H
C
k = 6
6D
C
k =
6
6T
C
k (D) 6
6H
C
k > 6
6D
C
k <
6
6T
C
k
Q.13 Which ofthe following is ortho-para directing group?
(A) CF3 (B) CCl3 (C) –CH=CH–COOH (D) – C
N 

Q.14 Matchthe column:
ColumnA ColumnB
(A) + CrO3 in CH3COOH  ? (P) Tropyliumion
(B) + Ph3C? (Q) Benzaldehyde
(C) + n-Pr Br + ZnCl2  ? (R) Two typesofproducts
(D) + Br2 ? (S) Cumene
Q.15 Matchthefollowing:
ColumnI ColumnII
(A) CO2is evolved from (P)
NaHCO3 bythe reaction of
(B) Libermann nitroso test is givenby (Q)
(C) Compounds givesyellow oily (R)
liquid on reaction with NaNO2 + HCl
(D) Compounds evolvea colourless gas (S)
onreactionwithactive metals

Q.16 Matchthefollowing:
ColumnI ColumnII
(A) Compounds whichonreaction (P)
with neutralFeCl3 gives
violet /Blue colour are
(B) Compounds whichonreaction (Q)
with
gives para red dye.
(C) Compounds whichdo not give (R) 3
2
2 CH
CH
C
CH
Ph
|
|
O



yellow ppt. Onreaction with NaOI
(D) Compound whichhave maximum% (S)
ofenolform
Q.17 Matchthefollowing:
ColumnI ColumnII
(A) Compounds whichgives Diels (P)
Elder's reactioningreater extent
withdienophile
(B) Compounds whichundergoes (Q)
ArSN reaction are
(C) Compound whichhas highest (R)
aromatic characters
(D) Strongest Base (S)
Q.18 Write the principalorganic product ineachofthe following reactions:
(i) + C6H5CH2SNa  H (ii) +
heat
THF
,
Mg


 


EXERCISE - IV(A)
Q.1 The chlorinationoftoluene inpresence offerric chloride gives predominatly:
(A) Benzylchloride (B) m-chlorotoluene (C) Benzalchloride (D) o-and p-chlorotoluene
Q.2 Aryl halidesarelessreactivetowardsnucleophilicsubstitution reaction ascompared to alkyl halidedueto
(A) Theformation of lessstablecarbonium ion (B) Resonancestabilization
(C) Longer carbon-halogen bond (D) Theinductiveeffect
Q.3 Themost basic compound among thefollowing is:
(A) Benzylamine (B)Aniline (C) Acetaniline (D) p-nitro aniline
Q.4 Chlorination of toluenein thepresenceof light and heat followed by treatment with aqueousNaOH
gives:
(A) o-cresol (B) p-cresol
(C) 2,4-dihydroxytoluene (D) Benzoic acid
Q.5 When nitrobenzene is treated with Br2 in presence of FeBr3 the major product formed is
m-bromonitrobenzene. Statements which are related obtainthe m-isomer are:
(A) The electrondensityonmeta carbonis more thanon ortho and para position.
(B) The intermediate carboniumionformed after initialattack ofBr+ attack the meta positionis least
destabilized.
(C) Loss ofaromaticitywhen Br+ attacks at the ortho and para positions and not at meta position
(D) Easier loss ofH+ to region aromaticityformthe meta positionthanfromortho and para position.
Q.6 Choose the correct statement fromthe ones givenbelow for two aniline in:
(A) II is not an acceptable canonicalstructure because carboniumions are less stable than ammonium
ions
(B) II is not an acceptable canonicalstructure because it is non aromatic
(C) II is not an acceptable canonicalstructure because the nitrogenhas 10 valence electrons
(D) II is an acceptable canonicalstructure
Q.7 Most stablecarboniumion is:
(A) p – NO2 – C6H4 – +CH2 (B) C6H5
+CH2
(C) p – Cl – C6H4– +CH2 (D) p – CH3O – C6H4 – +CH2
Q.8 Arrange in order ofdecreasing trend towards SE reactions:
(I) Chlorobenzene (II) Benzene (III)Aniliniumchloride (IV)Toluene
(A) II > I > III > IV (B) III > I > II > IV (C) IV > II > I > III (D) I > II > III > IV
Q.9 Among the followingstatements onthe nitrationofaromatic compounds, thefalse one is:
(A) Therate ofbenzene isalmost the same asthat ofhexadeuterobenzene
(B) The rate ofnitration oftoluene is greater thanthat ofbenzene.
(C) Therate ofnitration ofbenzene is greater thanthat ofhexadeuterobenzene
(D) Nitrationisanelectrophilic substitutionreaction
Q.10 Nitrobenzene can be prepared frombenzene byusing a mixture ofconc. HNO3 and conc. H2SO4. In
the nitrating mixture HNO3 actsas a:
(A) Base (B)Acid (C) Reducing agent (D) Catalyst
Q.11 Benzylchloride (C6H5CH2Cl) canbe prepared fromtoluenebychlorination with:
(A) SO2Cl2h (B) SOCl2 (C) Cl2 h (D) NaOCl

Q.12 The most unlikelyrepresentationofresonance structure ofp-nitrophenoxide ionis:
(A) (B) (C) (D)
Q.13 Asolutionof(+) -2-chloro-2-phenylethane intoluene racemises slowlyn the presenceofsmallamount
ofSbCl5, due to the formationof:
(A) Carbanion (B) Carbene (C) Free-radical (D) Carbocation
Q.14 Toluene, whentreatedwithBr2/Fe, givesp-bromotolueneasthe major product,because theCH3 group:
(A) is para directing (B) ismeta directing
(C) activates the ring byhyperconjugation (D) deactivatesthe ring
Q.15 Amongst thefollowingthe strongest base is:
(A) C6H5NH2 (B) p-O2NC6H4NH2 (C) m-O2NC6H4NH2 (D) C6H5CH2NH2
Q.16 Identifythe correctorderofreactivityinelectrophilic substitutionreactions ofthefollowing compounds:
(I) (II) (III) (IV)
(A) I > II > III > IV (B) IV > III > II > I (C) II > I > III > IV (D) II > III > I > IV
Q.17 F NO2 DMF
NH
)
CH
( 2
3



 
 A
Reduction
Catalytic
H
(ii)
C
5
0
HCl
NaNO
(i)
2
2






 




B
(A) O2N NH2 (B) N NH2
(C) N NO2 (D) N NO2
Q.18
Fe
Br2



Major product ofabove reaction is:
(A) (B) (C) (D)

Q.19 Whichofthefollowing is obtained when4-Methylbenzenesulphonic acid is hydrolysed with excess of
sodiumacetate?
(A) CH3
a
N
O
CO
— 
(B) CH3 + SO3
(C) CH3
a
N
SO3


+ CH3COOH (D) CH3 SO2O. COCH3 + NaOH
EXERCISE - IV (B)
Q.1 C6H5C2H5 NaCN
)
ii
(
Light
,
Heat
,
Br
)
i
( 2




 

Q.2 An organic compound (A). C8H6 ontreatment with dilutesulphuric acid containing mercuric sulphate
gives a compound (B), which can also be obtained froma reactionofbenzene with anacid chloride in
the presence ofanhydrous aluminiumchloride. Thecompound (B), whentreatedwithiodine inaqueous
KOH, yields (C) and a yellow compound (D). Identify(A), (B), (C) and (D) with justification. Show
how (B) is formed from(A) ?
Q.3 Toluene reacts withbromine inthe presence oflight to give benzylbromine while inpresence ofFeBr3 it
gives p-bromotoluene. Give explanationfor theabove observations.
Q.4 Show thesteps to carryout the following transformations:
(a) Ethylbenzene benzene
(b) Ethylbenzene 2-phenylpropionic acid
Q.5 C6H5CH2CHClC6H5 




 

heat
,
KOH
alcoholic (A) + (B)
Q.6 C6H5CH = CH2 

 2
Br (A)
I
CH
)
ii
(
)
equiv
0
.
3
(
NaNH
)
i
(
3
2






 
 (B)
Q.7 Normally, benzenegiveselectrophilicsubstitutionreactionratherthanthuselectrophilicadditionreaction
although it has double bonds.
Q.8 How would you synthesis 4 methoxyphenolfrombromobenzene in NOT more thanfive steps? State
clearlythe reagents used in eachstep and show the structures ofthe intermediate compounds in your
synthetic scheme.
Q.9 Carryout following conversions in3 or less steps.

Q.10 A compound C9H7O2Cl exists in keto form A and enolic form B. Enolic form B predominates at
equilibrium. On oxidationwith KMnO4 t gives m-chlorobenzoic acidgives structures ofAand B.
Q.11 7-bromo-1, 3, 5-cycloheptatrieneisioniccompound, whereas5-bromo-1,3-cyclopentadiene can't ionise
even n the presence ofAg, Explain why?

ANSWER KEY
EXERCISE - III
Q.1 D Q.2 B Q.3 B Q.4 A Q.5 B Q.6 A Q.7 B
Q.8 D Q.9 D Q.10 D Q.11 C Q.12 A Q.13 C
Q.14 (A) Q, (B) P, (C) R, S, (D) R Q.15 (A) Q, (B) P,R,S, (C) R,S, (D) P,Q,R,S
Q.16 (A) P,Q,R,S, (B) Q, (C) P,Q,R,S, (D) Q Q.17 (A) R, (B) S, R, (C) P, (D) S
Q.18 (i) (ii)
EXERCISE - IV(A)
Q.1 D Q.2 B Q.3 A Q.4 D Q.5 A,B Q.6 C Q.7 D
Q.8 C Q.9 C Q.10 A Q.11 A,C Q.12 C Q.13 D Q.14 A,C
Q.15 D Q.16 C Q.17 B Q.18 D Q.19 C
EXERCISE - IV (B)
Q.1 




h
,
Br2

 

NaCN
Q.2 (A) (B) (C)
Q.3 Inpresence ofFeBr3, Br2 produces Br+(anelectrophile) whichattacks the benzenering at o-,p-position
to give p-bromotoluene. In presence oflight, side chainis attacked to produce benzylbromide.
Q.4 (a) (i) C6H5CH(OH)CCH 
 


O
H3
C6H5CH=CHCHO C6H5CH=C=
OH
|
CH 
 


OH C6H5CH=C= H
C

(b) (i) 

]
O
[


 

e
lim
Soda
(ii)
hv
X2

 
 

KCN

 

HOH
Q.5 C6H5CH2CH2CHClC6H5 



 
 .)
alc
(
KOH
C6H5CH= CHC6H5
(Cis and trans forms)
Q.6 

 2
Br



 

.
eq
3
NaNH2

Q.7 Benzenehasresonance stabilizationduetodelocalisationof-electrons.Alsoduringelectrophilicaddition
reactions, it loses its aromaticity. Inelectrophilic substitutionreactionaromaticityis retained.
Q.8 essure
Pr
high
NaOH



 
 

 

4
2SO
Me 


 
 4
2SO
H
.
conc

 

NaOH

 


O
H3
Alternativerout



 
 4
2SO
H
.
conc

 

NaOH 

 

4
2SO
Me essure
Pr
high
NaOH



 
 
 


O
H3
Q.9




 
 4
2SO
H
.
conc




 
 2
4 KHF
/
HBF
Q.10 l
(A) (B)
Keto Enol
Enolformis more stable dueto extended conjugation
(A) 

 
 4
KMnO
Q.11 Onionization7-bromo-1,3,4-cycloheptatriene gives tropoliumionwhichis aromatic with6 electrons.
l + Brr
5-bromo-1,3-cyclopentadiene can't ioniseas it willinthat case give highlyunstable antiaromatic cation
with 4  electrons.
+ Brr