Which is the only alcohol that can be prepared by the indirect hydration of
alkene?
A. Ethyl alcohol
C. Isobutyl alcohol D. Methyl alcohol
B. Propyl alcohol
Which is the only alcohol that can be prepared by the indirect hydration of
alkene?
A. Ethyl alcohol
C. Isobutyl alcohol D. Methyl alcohol
B. Propyl alcohol
Among the alkenes which one produces tertiary butyl alcohol on acid
hydration?
D. CH3CH=CH2
A. (CH3)2C=CH2 B. CH3-CH=CH-CH3
C. CH3CH2CH=CH2
Among the alkenes which one produces tertiary butyl alcohol on acid
hydration?
D. CH3CH=CH2
A. (CH3)2C=CH2 B. CH3-CH=CH-CH3
C. CH3CH2CH=CH2
In the reaction given below, the molecular formula of X is;
A. C4H6O
C. C2H4O D. C2H6O
B. C4H10O
Solution:
Chemical Reactions
Halogenation
Nitration
Sulphonation
Kolbe's reaction
Friedel crafts
reaction
Phenols
Reimer-Tiemann
reaction
Claisen
rearrangement
Mercuration
Hydrogenation
Gattermann's
reaction
Electrophilic Substitution Miscellaneous Reactions
Reaction with Zn
dust Coupling reaction
Condensation with
formaldehyde
Chemical Reactions of Phenols
Electrophilic Substitution Reactions
• The –OH group attached to the benzene ring activates phenols towards
electrophilic substitution.
i) Nitration
Chemical Reactions of Phenols
Electrophilic Substitution Reactions
ii) Halogenation
• Bromine water on reaction with phenol gets decolorized and a white ppt of
2,4,6-Tribromophenol is formed.
Chemical Reactions of Phenols
Electrophilic Substitution Reactions
iv) Friedel–Craft Alkylation Reaction
Chemical Reactions of Phenols
Electrophilic Substitution Reactions
iv) Friedel–Craft Acylation Reaction
Phenol on treatment with conc.HNO3 gives:
A. Picric acid
C. Ortho and para-
nitrophenolD. None of the above
B. Ortho and meta-
phenol
Phenol on treatment with conc.HNO3 gives:
A. Picric acid
C. Ortho and para-
nitrophenolD. None of the above
B. Ortho and meta-
phenol
Solution:
Chemical Reactions of Phenols
1. Kolbe-Schmidt reaction/ Kolbe's reaction
• Reaction of sodium phenoxide with carbon dioxide at 130-140°C under
pressure of (4-7) atmospheres followed by acid hydrolysis forms salicylic acid
(o-Hydroxy benzoic acid).
Miscellaneous Reactions
Chemical Reactions of Phenols
1. Kolbe-Schmidt reaction/ Kolbe's reaction
Mechanism
• Nucleophilic addition of phenoxide to carbon dioxide yields salicylate.
• The salicylate formed further reacts with the acid to form salicylic acid
Chemical Reactions of Phenols
2. Reimer-Tiemann reaction
• When phenol is treated with chloroform in the presence of NaOH, a –CHO group
is introduced at ortho position of benzene ring and salicylaldehyde is formed.
Chemical Reactions of Phenols
2. Reimer-Tiemann reaction
• When carbon tetrachloride is used, salicylic acid (predominating product) is
formed.
Chemical Reactions of Phenols
3. Gattermann’s reaction
• Phenol on reaction with liquid hydrogen cyanide and hydrochloric acid gas in
presence of anhydrous aluminium chloride yields p-hydroxy benzaldehyde
(Formylation).
Chemical Reactions of Phenols
4. Mercuration
• Phenol when heated with mercuric acetate undergoes Mercuration to form o- and p-
isomers.
Chemical Reactions of Phenols
5. Hydrogenation
• Phenol, when hydrogenated in presence of a nickel catalyst at about 150-200°C,
forms cyclohexanol.
A new C-C bond formation is possible in:
A. Cannizaro reaction
C. Clemmensen reduction D. Reimer-Tiemann
reaction
B. Rosenmund’s reduction
A new C-C bond formation is possible in:
A. Cannizaro reaction
C. Clemmensen reduction D. Reimer-Tiemann
reaction
B. Rosenmund’s reduction
Chemical Reactions of Phenols
5. Claisen rearrangement
• Rearrangement of allyl aryl ethers to allyl phenols.
• The reaction takes place when the substrate is heated alone to about 200°C or in
some inert solvent like diphenyl ether.
• Allyl group migrates to ortho-position and if ortho-position is already occupied,
para-isomer is obtained.
Chemical Reactions of Phenols
7. Reaction with zinc dust
• When phenol is distilled with zinc dust, benzene is obtained.
Chemical Reactions of Phenols
8. Coupling Reaction
• Phenol couples with benzene diazonium chloride in presence of slightly
alkaline medium at low temperature to form a red dye (p-hydroxy
azobenzene).
Chemical Reactions of Phenols
8. Coupling Reaction
• Phenol couples with phthalic anhydride in presence of concentrated H2SO4 to
form a dye, (phenolphthalein)used as an indicator.
Chemical Reactions of Phenols
9. Condensation Reaction with Formaldehyde
• Phenol condenses with formaldehyde (excess) in presence of sodium
hydroxide or acid to form a cross-linked polymer known as Bakelite.
• Bakelite is used to manufacture electrical goods.
Identification Tests for Phenols
1.Reaction with ferric chloride.
• Aqueous solution of phenol gives a violet coloration with a drop of ferric
chloride.
Identification Tests for Phenols
2. Reaction with bromine water
• Aqueous solution of phenol gives a white precipitate of 2,4,6-tribromophenol
with bromine water.
Identification Tests for Phenols
3. Liebermann's nitroso reaction
• When phenol is reacted with NaNO2 and concentrated H2SO4, it gives a deep
green or blue colour which changes to red on dilution with water.
• When made alkaline with NaOH original green or blue colour is restored.
Identification Tests for Phenols
4. Reaction with phthalic anhydride
• Phenol combines with phthalic anhydride in presence of conc. H2SO4 to form
phenolphthalein which gives pink colour with alkali and is used as an indicator.
Phenol can be distinguish from ethyl alcohol using:
A. Na
C. NaOH D. FeCl3
B. AlCl3
Solution:
Phenol with FeCl3 gives violet colour. This test is not given by ethyl alcohol.
SOME COMMERCIALLY IMPORTANT ALCOHOLS
• The simplest monohydric alcohol.
• Also referred as wood alcohol or wood spirit or wood naphtha.
• It occurs in combined state in some essential oils, e.g., oil of winter green
(methyl salicylate), oil of cloves (methyl benzoate), oil of orange flowers
(methyl anthranilate), etc.
SOME COMMERCIALLY IMPORTANT ALCOHOLS
2. Ethyl Alcohol
• Glucose and fructose undergo fermentation in the presence of enzyme zymase
to form ethyl alcohol
Uses of Phenols
Phenol
Antiseptic
Dyes
Picric Acid
Cyclohexanol
Phenol-formaldehyde plastic
Drugs
Disinfectant
Phenol on distillation with zinc dust gives:
AIIMS 2018
D. zinc powder
A. benzene B. diphenyl ether
C. biphenyl
Phenol on distillation with zinc dust gives:
AIIMS 2018
D. zinc powder
A. benzene B. diphenyl ether
C. biphenyl
Solution
:Identify X and Y in the above reaction
NEET 2021
D. X is phenols, Y is Zinc
powder
B. X is Phenol, Y is
Na2Cr2O7/ H2SO,
C. X is cyclohex-2-ene-1-
ol,Y is Na2Cr2O2/H2SO4
A. X is cyclohexanol, Y is
Zn
:Identify X and Y in the above reaction NEET 2021
B. X is Phenol, Y is
Na2Cr2O7/ H2SO,
C. X is cyclohex-2-ene-1-
ol,Y is Na2Cr2O2/H2SO4
A. X is cyclohexanol, Y is
Zn
D. X is phenols, Y is Zinc
powder
Solution
Chloroform gives salicylaldehyde on treatment with phenol in the presence of
a base. This reaction is called as:
[ NEET 2018]
D. Cannizaro’s reaction
A. Wurtz reaction B. Reimer-Tiemann
reaction
C. Friedel-Crafts
reaction
Chloroform gives salicylaldehyde on treatment with phenol in the presence of
a base. This reaction is called as:
[ NEET 2018]
D. Cannizaro’s reaction
A. Wurtz reaction B. Reimer-Tiemann
reaction
C. Friedel-Crafts
reaction
Solution
Summary
Reactions of Phenols
Electrophilic Substitution Reactions
iii. Sulphonation iv. Friedel–Craft
reaction
Summary
Reactions of Phenols
Miscellaneous Reactions
1. Kolbe-Schmidt reaction 2. Reimer-Tiemann reaction
Summary
Reactions of Phenols
Miscellaneous Reactions
7. Reaction with zinc dust 8. Coupling Reaction
SummaryTest for Phenols
Importance of:
• Methanol
• Ethyl Alcohol
• Phenols
1. Reaction with Ferric chloride
2. Reaction with bromine water
3. Liebermann's nitroso reaction
4. Reaction with phthalic anhydride