This presentation includes all the preparations and reactions of various Polynuclear hydrocarbons as naphthalene, Phenanthrene, anthracene,diphenylmethane,triphenylmethane and their derivatives.This is made by the b Pharmacy 2 year students of Gurunanak College of Pharmacy Nagpur as a group activity which focussed on student participation.

1. (Synthesis and Reactions)
Presented by-
Parul Babhulkar
Mariya Amravatiwala
Kartik Kanugo
Vinayak Laghate
Vaishnav kore
2nd year B.pharm, Gurunanak college of pharmacy,
Nagpur
Guided by: Prof. Pradyna Gondane

2. 
Classification:

3. 
1. Haworth Synthesis:
Synthesis of Naphthalene:
Benzene
Succinic
anhydride
3-Benzoyl
propanoic acid
(Clemmenson
Reduction) 4-phenyl
butanoic acid
-tetralone
Tetralin
Napthalene
(for ring closure of
acids,
sulphuric,phosphor
ic,HF and PPA are
commonly used as
catalyst.)

4. 
2. From 4-phenyl-3-enoic acid(Fitting reaction):
Synthesis of Naphthalene:

5. 
3.From 4-phenylbut-1-ene:
Synthesis of Naphthalene:

6. 
 Naphthalene is more reactive than benzene
because it undergoes more easily oxidation,
reduction,addition reactions, and
electrophilic substitution reactions as
compared to benzene.
1. Oxidation of naphthalene: These are
Various oxidation reactions of naphthalene.
Chemical Reactions of Naphthalene:

7. 
2. Reduction reactions of naphthalene:
Chemical Reactions of Naphthalene:

8. 
3.Addition reactions of naphthalene:
Further dehydrohalogenation of these (di and tera) napthalene halides results
in the formation of substituted halo-napthalene derivatives which on
oxidation gives pthalic acid.
Chemical Reactions of Naphthalene:

9. 
 In naphthalene electrophile attack preferably at C1
position( -carbon).the various electrophilic
substitution reactions are as follows:
a) Nitration: nitration of naphthalene occurs at room
temperature.
Electrophilic substitution reactions of
naphthalene:

10. 
b)Halogenation:
c) Friedel-crafts Alkylation: It is carried out in mild
conditions(low temp.)
Electrophilic substitution reactions of
naphthalene:

11. 
 In case of naphthalene react with bromopropane yields 2-isopropyl
naphthalene a the propyl cation formed during reaction rearranges to
a more stable isopropyl cation.
d)Friedel-crafts acylation:It depends upon nature of solvent used.
Electrophilic substitution reactions of
naphthalene:

12. 
e)Sulfonation:
Electrophilic substitution reactions of
naphthalene:

13. Orientation of Electrophilic substitution in Naphthalene:
Naphthalene Nitration Nitronium ion (NO2
+)
Halogenation Chloronium ion (Cl+ )
Halonium ion ( X +)
α- position of
Naphthalene
+ E+ Electrophilic substitution reaction
More preferable
α-position
β
So, attack of electrophile can occur at α-position or β-position.
α

14. Conjugated system
Regular conjugation
(alternate single-double bonds)
More stable
Cross conjugation
(not a continuous chain)
Less stable

15. As per Morrison:-
Like benzene, the polynuclear hydrocarbon naphthalene typically undergoes
electrophilic substitution which entitle it to be "aromatic".
Nitration and halogenation occur almost exclusively in the α-position.
When we consider nitration, attack by nitronium ion at the α-position of
naphthalene yields an intermediate carbocation that is a hybrid of structures I
and II in which the positive charge is accommodated by the ring under
attack, and several structures like III in which the charge is accommodated by
the other ring.

16. Attack at the β-position yields an intermediate carbocation that is a hybrid of IV
and V in which the positive charge is accommodated by the ring under attack,
and several structures like VI in which the positive charge is accommodated by
the other ring.
In structures I, II, and IV, the aromatic sextet is preserved in the ring that is not under
attack; these structures thus retain the full resonance stabilization of one benzene ring
(36 kcal/mol). In structures like III, V, and VI, on the other hand, the aromatic sextet is
disrupted in both rings, with a large sacrifice of resonance stabilization. Clearly,
structures like I, II, and IV are much the more stable.
But there are two of these stable contributing structures (I and II) for attack at the α-
position and only one (IV) for attack at the β-position. On this basis we would expect the
carbocation resulting from attack at the α-position (and also the transition state leading
to that ion) to be much more stable than the carbocation (and the corresponding
transition state) resulting from attack at the β-position, and that nitration would
therefore occur much more rapidly at the α-position.

17. Orientation of Electrophilic Substitution in Naphthalene
Derivatives:
• Activating group(e¯ releasing ) Further substitution Same ring
1st position further substitution on 4th position (and, to a lesser
extent on 2nd position).
2nd position further substitution on 1st position.
For example:

18. • Deactivating group (e- withdrawing) Further substitution other ring
at α- position in nitration or halogenation.
At α- or β- position (depending upon temperature) sulfonation.
For example:
These rules do not always hold in sulfonation , because the reaction is
reversible and at high temperatures tends to take place at a β-position .

19. 
 Naphthol
Synthesis:
i.Two types of naphthols (i.e. or β-naphthol) occurs in
small quantities in coal tar.
Derivatives of naphthalene:

20. 
ii.1-Naphthol can also be prepared by hydrolysis of 1-
Napthylamine with sulfuric acid at 180◦C.
Derivatives of naphthalene:

21. 
Chemical reactions of naphthol: Naphthols undergo coupling
reactions with benzene diazonium salts and forms azo dyes.
-Naphthols gives violet color whereas β-Naphthol gives green
color with ferric chloride solution. This reaction is used for
quantitative estimation of and β-naphthols.
Derivatives of naphthalene:

22. 
 Naphthylamines
Synthesis:(a) From Naphthol(Bucherer reaction):
(b)From 1-Nitronaphthalene:
Derivatives of Naphthalene:

23. 
Chemical reactions:
(a)When 1-napthylamine is reacted with sulfuric acid it yiels naphthionic acid
,which is used in dye industry.
(b)Diazonium salts of naphthylamine:
Derivatives of Naphthalene:

24. 
The diazonium salt of
naphthylamine can be used for
preparation of other substituted
naphthalene derivatives .
Derivatives of Naphthalene:

25. 
 Naphthanoic acid
Synthesis
(a)From Grignard Reagent:
(b)By idoform reaction:
Derivatives of Naphthalene:

26. 
(c) Kolbe Schmitt reaction:
Derivatives of Naphthalene:

27. 
 Naphthoquinones
(1) 1,2-Napthoquinone
Derivatives of Naphthalene:

28. 
(2) 1,4-Naphthoquinone
Derivatives of Naphthalene:

29. 
(3)2,6-Napthoquinone- it is strong oxidising agent of all
naphthoquinones.
Chemical reaction of 1,4-Naphthoquinones:
Derivatives of Naphthalene:

30. 
1.Friedel-crafts reaction:
i)From benzyl chloride:
ii)From benzene and 1,1,2,2-tetrabromoethane:
iii)From benzene and phthalic acid:
Synthesis of Anthracene:

31. 
2.Elbs reactions: by this methods anthracene is prepared by pyrolysis
of o-methylbenzophenone.
3.Diels-Alder reactions:
Synthesis of Anthracene:

32. 
a)Electophilic substitution reactions:
Chemical reactions of anthracene:

33. 
(b) Diels-Alder reaction:
Anthracene undergoes Diels-Alder reaction at 9,10
positions and forms endo-anthracene maleic anhydride.
Chemical reactions of anthracene:

34. 
(c)Other reactions of anthracene:
Chemical reactions of anthracene:

35. 
i)Anthrone: It is stable,colourless solid having m.p. 154◦C.It is
synthesized by heating anthranol.
It can also be prepared by heating o-benzylbenzoic acid with HF.
Derivatives of anthracene:

36. 
Or it may be prepared by reduction of anthraquinone with tin and
HCl in glacial acetic acid.
ii)Anthraquinone: Among the various isomeric quinones of
anthracene only three isomers are well known i.e 1,2-,1,4- and 9,10.
But only 9,10- compound is referred simply as anthraquinone.
Derivatives of anthracene:
HCl,CH3COOH

37. 
Synthesis of anthraquinone:
(a)
(b)
Derivatives of anthracene:

38. 
 Chemical reactions of Anthraquinone:
1) Reduction reactions:
Derivatives of anthracene:

39. 
2)Electrophilic substitution reactions: The outer rings of
anthroquinone are aromatic in nature and capable for substitution
reactions. But the presence of two electron withdrawing carbonyl
groups deactivate the aromatic rings towards electrophilic
substitution. However under vigrous conditions anthraquinone
undergo nitration and sulfonation.
Derivatives of anthracene:

40. Electrophilic substitution reactions:

41. 
iii)2-Aminoanthraquinone:
Synthesis
The sodium arsenate oxidises the liberated sulphite which other wise
would attack the amine product.
Derivatives of anthracene:

42. 
Reactions of 2-Aminoanthraquinone:
Derivatives of anthracene:

43. 
1)Haworth Synthesis:
Synthesis of Phenanthrene:
3(1-napthyol)propanoic
acid
4-(1-napthyl)butanoic
acid
Cyclic ketone

44. 
2)Pschorr synthesis: O-nitrobenzaldehyde is heated with sodium
B-phenylacetate in the presence of acetic anhydride gives a-
phenyl-o-nitro cinnamic acid (1) which is diazotised with
NaNO,/H.SO, followed by treatment with sulphuric acid and cop
per powder phenanthrene-9-carboxylic acid is obtained (2). The
compound (2) on strong heating give phenanthrene.
Synthesis of Phenanthrene:

45. 
Chemical reactions of Phenanthrene:

46. 
 Phenanthraquinone : It is an orange solid which is
odorless and not steam volatile.It can be synthesized
as follows:
Derivatives of Phenanthrene:

47. 
Reactions of Phenanthraquinone:
Derivatives of Phenanthrene:

48. 
1.Friedel-Crafts condensation:
2.Condensation of Formaldehyde:
Synthesis of Diphenyl Methane:

49. 
3.From Grignard reagent:
4.Wolff-Kishner reduction :
Synthesis of Diphenyl Methane:

50. 
Chemical Reactions of Diphenylmethane:

51. 
1.Friedel-Crafts reaction:
a)
b)
2.Triphenylmethane can also be prepared by reacting the benzaldehyde
with benzene in presence of ZnCl2 as catalyst.
Synthesis of Triphenylmethane:

52. 
Chemical reactions of Triphenylmethane: