Q20 of 26 Page 1

How do you convert the following:

(i) Phenol to anisole


(ii) Propan-2-ol to 2-methylpropan-2-ol


(iii) Aniline to phenol


OR


(a) Write the mechanism for the following reaction:



(b) Write the equation involved in the acetylation of Salicylic acid.


(i) Phenol(is initially reacted with sodium hydroxide(NaOH) to give sodiumphenoxide ( which readily reacts with alkylhalide to give ether. This reaction is called Williamson ether synthesis. In this case we require phenylmethlyether. So is reacted with methylbromide (CH3Br).


(ii) Propan-2-ol( is first oxidised to propanone (using potassium dichromate(K2Cr2O7), which on reacting with Grignards reagent(and hydrolysis gives 2-methylpropan-2-ol(




(iii) Aniline( on treatment with gives benzene diazonium chloride( which is highly unstable and gets hydrolysed to give phenol(



OR


(a) Two molecules of primary alcohol condense in presence of acid to give ether.


Step1: The proton from acid gets attacked by the alcoholic oxygen to form alkyloxonium ion.



Step 2: Alkyloxonium ion formed in step 1 undergoes nucleophilic attack by another alcohol molecule.



Step 3: The hydrogen attached to oxygen is lost as proton to give di ethyl ether.



(b)


Step 1: Acetylation of salicylic acid is done in the presence of a little acid. The protons from the acid are attracted towards the oxygen in carbonyl carbon which polarises the anhydride.



Step2: This polarised anhydride is attacked by the hydroxyl oxygen from salicylic acid to give aspirine.



More from this chapter

All 26 →