Phenols Flashcards
Coupling Reaction
Phenol and benzene diazonium chloride
Forms:
p-hydroxyazobenzene
Dow’s Process
Chloro benzene and NaOH followed by treatment with dil. HCl
Forms:
Phenol
Reimer Tiemann’s Reaction 🌚
or
Formylation reaction
Phenol and chloroform in presence of NaOH/KOH at 67•C
Forms:
Salicyaldehyde
If CCl4 is used then salicylic acid is formed
Kolbe’s Reaction
or
Carboxylation Reaction
Sodium phenoxide with CO2 at 127•C and 4-7 atm
Forms:
Salicylic acid
Libermann’s Test
Test of phenol
Phenol+ HNO2 in presence of conc H2SO4 gives red and brown colouration. It changes to blue or green when NaOH is added.
Preparation of phenol from sodium benzene sulphonate?
1) Benzene sulphonic acid + NaOH —> sodium benzene sulphonate
2) Fusion with Na —> sodium phenoxide
3) Treatment with dil. NaOH —> phenol
Preparation of phenol from Benzene diazonium chloride?
Heat with water
Acidic strength compared to alcohol?
More acidic since -OH group activates benzene ring and decreases electron density around O and alkyl group is electron donating group that increases electron density around O.
Reaction of phenol with Zn dust?
Benzene
Reaction of phenol with NH3?
Aniline
Reaction of phenol with pthalic anhydride?
Phenolphthalein.
Acylation of phenol?
R- COCl—> phenyl ethanoate + HCl
R-CO-O-CO-R—> phenyl ethanoate + carboxylic acid
Halogenation of phenol?
(Aquarius bromine test)
2,4,6 tribromo phenol gives white ppt.
Nitration of phenol?
Picric acid.
Sulphonation of phenol?
At lower temp.
o-hydroxy benzene sulphonic acid
At higher temp.
p- hydroxy benzene sulphonic acid
