question_answer

                In Friedel-Craft?s synthesis of toluene, the reactants in addition to anhydrous \[AlC{{l}_{3}}\] are:

A)                                                                                                                                                                                           \[{{C}_{6}}{{H}_{5}}Cl+C{{H}_{4}}\]

B)                 \[{{C}_{6}}{{H}_{5}}Cl+C{{H}_{3}}Cl\]

C)                 \[{{C}_{6}}{{H}_{6}}+C{{H}_{4}}\]

D)                 \[{{C}_{6}}{{H}_{6}}+C{{H}_{3}}Cl\]

Correct Answer: D

Solution :

                Friedel-Crafts alkylation of benzene (Ar-H)                 Step (i)                \[\underset{Electrophile}{\mathop{C{{H}_{3}}ClAlC{{l}_{3}}\xrightarrow[{}]{{}}\overset{+}{\mathop{C}}\,{{H}_{3}}+AlCl_{4}^{-}}}\,\]                 Step (ii)                                 Step (iii)                                 Thus, \[{{C}_{6}}{{H}_{6}}\] and \[C{{H}_{3}}Cl\] are required in addition to \[AlC{{l}_{3}}\]