Benzene and Alkyl Benzene - Result Question 48
####52. Answer the following with suitable equation wherever necessary
(i) How can you prepare benzene from lime?
(ii) How will you convert toluene to $m$-nitrobenzoic acid?
$(1987,2 M)$
Show Answer
Solution:
- (i) Lime is heated with coke at high temperature and then, hydrolysed to form acetylene. This acetylene on passing red hot tube polymerises to form benzene :
$$ \underset{\text { Lime }}{CaO}+\underset{\text { Coke }}{3 C} \xrightarrow{2000^{\circ} C} CaC _2+CO \uparrow $$
$$ \begin{gathered} CaC _2+2 H _2 O \longrightarrow Ca(OH) _2+\underset{\text { Acetylene }}{C _2 H _2} \ 3 C _2 H _2 \xrightarrow[\Delta]{Cu} \underset{\text { Benzene }}{C _6 H _6} \end{gathered} $$
(ii) $-CH _3$ in toluene is ortho/para directing group, first oxidised to $-COOH$ in order to make it meta directing and then nitrated.
