--%>
Assignment Help - homework help

Explain the preparation of phenols.

The methods used for the preparation of phenols are given below:
    
From aryl sulphonic acids

Aryl sulphonic acids on fusion with NaOH at 573 K followed by acidification yield phenols.

1616_Phenol preparation.png 

From aryl halides (Dow's process)

Phenol is obtained on a large scale by heating chlorobenzene with 10% NaOH solution at about 623 K and under a pressure of 300 atmospheres in the presence of copper catalyst.

1327_Phenol preparation1.png 

From diazonium salts

In the laboratory phenols are prepared hydrolysis of diazonium salts with water or dilute acids.

994_Phenol preparation2.png 
    
By decarboxylation of sodium salt of saclicyclic acid

Phenol can also be obtained by the decarboxylation of sodium salicyclate with soda lime (an equimolar mixture of NaOH and CaO).
                           
289_Phenol preparation3.png 
    
From Grignard's reagent

when oxygen is bubbled through the solution of phenylmagnesium bromide in ether, it forms an addition product which on acidification with dilute acid gives phenol.

1498_Phenol preparation4.png

   Related Questions in Chemistry

  • Q : Describe the properties of the

    Briefly describe the properties of the carbohydrates?

    		•
  • Q : What are lattices and unit cells? The

    The repeating, atomic level structure of a crystal can be represented by a lattice and by the repeating unit of the lattice, the unit cell.It was apparent very early in the study of crystals that the shapes of crystals stem from an ordered array of smaller

    		•
  • Q : What are isotonic and hypotonic

    The two solutions which are having equivalent osmotic pressure are called isotonic solutions. The isotonic solutions at the same temperature also have same molar concentration. If we have solutions having different osmotic pressures then the solution having different

    		•
  • Q : What are heterogenous catalysis? Give

    When the catalyst exists in a different phase than that of reactants, it is said to be heterogeneous catalyst, and the catalysis is called heterogeneous catalysis. For example, SO2 can be oxidized to SO3

    		•
  • Q : Number of mlecules in methane Can

    Can someone please help me in getting through this problem. The total number of molecules in 16 gm of methane will be: (i) 3.1 x 1023 (ii) 6.02 x 1023 (iii) 16/6.02 x 1023 (iv) 16/3.0 x 1023

    		•
  • Q : Why aryl halides are less reactive?

    Aryl halides are much less reactive towards nucleophilic substitution reactions than haloalkanes. The less reactivity of aryl halides can be described

    		•
  • Q : Electrochemistry ( electrolysis of

    1. Define Faraday's first law of electrolysis 2. define Faraday's second law of electrolysis

    		•
  • Q : Molar mass of solute The boiling point

    The boiling point of benzene is 353.23 K. If 1.80 gm of a non-volatile solute was dissolved in 90 gm of benzene, the boiling point is increased to 354.11 K. Then the molar mass of the solute is: (a) 5.8g mol-1  (b)

    		•
  • Q : Problem on reversible process a. For a

    a. For a reversible process involving ideal gases in a closed system, Illustrate thatΔS = Cv ln(T2/T1) for a constant volume process ΔS = Cp ln(T2/T1) for a constant pressu

    		•
  • Q : Hydroxide is highly insoluble in

     : 1) Chromium(III) hydroxide is highly insoluble in distilled water but dissolves readily in either acidic or basic solution. Briefly explain why the compound can dissolve in acidic or in basic but not in neutral solution. Write appropriate equations to

    		•