The document summarizes the Friedel-Crafts reaction, which introduces an alkyl or acyl group into an aromatic ring using an acid catalyst. It describes the two main types of reactions - alkylation and acylation. The mechanism of the reactions involves electrophilic aromatic substitution through a Wheland intermediate for alkylation or reaction with an acyl cation for acylation. Common reagents, catalysts, and their reactivity orders are provided. Applications discussed include the synthesis of naphthalene, anthracene derivatives, pyrrole derivatives, muscone, dyes, and cyclopentanone derivatives.

1. Friedel Craft Reaction
SAKSHAM PALAWAT
2017H1470271P
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2. Friedel-Craft Reaction
Saksham palawat
2017H1470271P
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3. Introduction:-
• Introduction of alkyl or acyl group into an aromatic nucleus in the
presence of acid catalyst (usually Lewis acids) is known as
Friedel-Craft reaction.
• Friedel-Craft reactions are broadly classified into two categories: -
a) Friedel-Craft alkylation reaction.
b) Friedel-Craft acylation reaction
Brahmachari Goutam, “Organic Name Reaction, A Unified Approach”,page no- 251
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5. Mechanism:- Friedel- Craft Alkylation reaction
• The Friedel-Craft reaction follows the pathway of aromatic electrophilic substitution
reaction, involving the formation of Wheland intermediate. It is evident in most of the
cases the electrophile is carbocation
Brahmachari Goutam, “Organic Name Reaction, A Unified Approach”, page no- 252
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6. Mechanism of Electrophilic aromatic substitution reaction :-
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7. Mechanism of Friedel-Craft Acylation Reaction
Brahmachari Goutam, “Organic Name Reaction, A Unified Approach”, page no- 254
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8. Reagents and catalysts and reactivity order
Friedel-Craft alkylation reaction: -
Reagent and catalyst: -
• The generally used alkylating agents are alkyl halides, alkenes and alcohol
• The order of reactivity of alkyl halides: -
• F > Cl > Br > I
• However, order of reactivity of all type of reagent are: -
• Allylic ~ Benzylic > tertiary > secondary > primary
• Thus, benzene on treatment with FCH2-CH2-Cl in the presence of BCl3 yields chloroethyl benzene.
• The most common catalyst used in the reaction are anhydrous AlCl3 and BF3 both are Lewis acids.
sometime proton acid such as HF, H2SO4, H3PO4 are used.
• For more active halides, trace amount of catalyst is enough (e.g. ZnCl2) is enough. But in case of
lesser active halides, more active catalyst (e.g. AlCl3) is required in more amounts.
Brahmachari Goutam, “Organic Name Reaction, A Unified Approach”, page no- 253
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9. continued
• The order of effectiveness of Lewis acid catalyst are: -
Friedel-Craft acylation reaction: -
• This is a good method for the preparation of aryl ketones.
• Acylating Reagents: - acyl halides, carboxylic acids, acid anhydride, ketenes. Among acyl
halides, chlorides are most commonly used.
• Catalyst: - Polyphosphoric acid, Aluminum trichloride (AlCl3).
Brahmachari Goutam, “Organic Name Reaction, A Unified Approach”,page no- 251
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10. Friedel-Craft acylation reaction having other alternatives
• This electrophilic aromatic substitution allows the synthesis of monoacylated products from the reaction
between arenes and acyl chlorides or anhydrides. The products are deactivated, and do not undergo a
second substitution. Normally, a stoichiometric amount of the Lewis acid catalyst is required, because
both the substrate and the product form complexes.
• The Friedel-Crafts Alkylation may give polyalkylated products, so the Friedel-Crafts Acylation is a
valuable alternative. The acylated products may easily be converted to the corresponding alkanes via
Clemmensen Reduction or Wolff-Kishner Reduction.
http://www.organic-chemistry.org/namedreactions/friedel-crafts-acylation.shtm
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11. Types of Friedel-Craft Acylation Reaction
• Intermolecular Friedel-Craft Acylation Reaction: -
• Intramolecular Friedel-Craft Acylation Reaction: -
Jie Jack Li, Name Reaction , A detailed collection of Reaction Mechanism
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12. Applications:-
• Acylation of polycyclic aromatic hydrocarbons :
1. Synthesis of Naphthalene: -Friedel crafts reaction of succinic anhydride with benzene in presence of
AlCl3 gives a ketonic acid I which is reduced to II. This on cyclisation gives ketone III which on reduction
yields tetralin IV. Dehydrogenation of tetralin gives naphthalene.
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13. Synthesis of Poly Hydrocarbons
2. Synthesis of anthracene derivatives:-
Friedel crafts alkylation between two molecules of benzyl chloride gives 9.10-dihydroanthracene
which oxidized readily under the reaction conditions yielding anthracene.
www.devchandcollege.org/e-NOTES/SSD%2015.pdf
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14. Applications:-
• 3. Synthesis of pyrrole 3-acylated derivatives:
• Brahmachari Goutam, “Organic Name Reaction, A Unified Approach", page no- 251
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15. Reaction With new Catalyst Zinc oxide (ZnO)
4. Acylation Reaction over Zinc Oxide (ZnO) as a New Catalyst: -
• Zinc oxide (ZnO) catalyzes a rapid Friedel-Crafts acylation of various aromatic compounds
with acid chlorides in solvent-free conditions at room temperature.
• The ZnO powder can be reused up to three times after simple washing with dichloromethane.
http://www.organic-chemistry.org/namedreactions/friedel-crafts-acylation.shtm
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16. Synthesis of Muscone
5. Synthesis of muscone, an effective perfumery product: - Cyclododecene react slowly with crotonyl
bromide at -78°c to furnish ketone that is an important intermediate in the synthesis of muscone.
Brahmachari Goutam, “Organic Name Reaction, A Unified Approach”,page no- 258
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17. Dyes making
6. In making of Dyes: -
Friedel–Crafts reactions have been used in the synthesis of several triaryl methane and
xanthene dyes. Examples are the synthesis of thymolphthalein (a pH indicator) from two
equivalents of thymol and phthalic anhydride.
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18. Cyclopentanone derivatives synthesis
7. Synthesis of Cyclopentanone derivatives: - Cyclohexene on reaction with crotonyl
chloride yields cyclopentenone derivatives as one of the products, which is important
precursor of terpenoids.
• Brahmachari Goutam, “Organic Name Reaction, A Unified Approach", page no- 257
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19. Thank You
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