how can you prepare phenol from benzene write the steps only
Answers
Method I
First do chlorination of Benzene by reacting it with Chlorine gas in presence of either Ferric chloride or anhydrous Aluminium chloride or red Phosphorus to get chlorobenzene
C6H6+Cl2−→−−−−an.AlCl3C6H5Cl+HCl
Then heat the chlorobenzene with steam at 698K using calcium phosphate or silica to get required Phenol
C6H5Cl+H2O−→−−−−−−−−−Ca3(PO4)2/698KC6H5OH+HCl
Method II
First do chlorination of Benzene by above-mentioned reaction, then react this chlorobenzene with Sodium hydroxide at 613K under 300atm pressure to get Sodium phenoxide
C6H5Cl+2NaOH−→−−−−−−−613K/300atmC6H5ONa+NaCl+H2O
React this Sodium phenoxide with Hydrochloric acid to get required Phenol
C6H5ONa+HCl→C6H5OH+NaOH
Method III
First react Benzene with isopropyl chloride in presence of anhydrous Aluminium chloride to get isopropyl benzene (cumene)
C6H6+(CH3)2CHCl−→−−−−an.AlCl3C6H5CH(CH3)2
Then oxidize this cumene by passing air/oxygen over it in presence of cobalt naphthenate & alkaline medium at 423K to get cumene hydroperoxide
C6H5CH(CH3)2+O2−→−−−−−−−−−−−−cobalt napthenate/423KC6H5C(CH3)2−O−OH
Heat this cumene hydroperoxide with dilute sulphuric acid to get required Phenol & acetone
C6H5CH(CH3)2+O2−→−−−−−dil.H2SO4C6H5OH+(CH3)2C=O
Method IV
First react benzene with oleum (concentrated sulphuric acid) to get benzene sulphonic acid
C6H6+HO−SO3H→C6H5SO3H+H2O
Neutralize this benzene sulphonic acid by reacting it with caustic soda (sodium hydroxide) to get Sodium benzene sulphonate
C6H5SO3H+NaOH→C6H5SO3Na+H2O
Fuse this sodium benzene sulphonate with excess of caustic soda to get sodium phenoxide
C6H5SO3Na+2NaOH−→−−fused573KC6H5ONa+Na2SO3+H2O
Treat this sodium phenoxide with dilute sulphuric acid to get required Phenol
C6H5ONa+H2SO4−→ΔΔC6H5OH+Na