question_answer

Consider the following reaction     [AIPMT (S) 2009]

\[\text{Phenol}\,\xrightarrow[{}]{\text{Zndust}}X\xrightarrow[\text{Anhydrous }AlC{{l}_{3}}]{C{{H}_{3}}Cl}Y\xrightarrow[{}]{\text{Alkaline }KMn{{O}_{4}}}Z,\]     the product Z is

A) toluene

B) benzaldehyde

C) benzoic acid

D) benzene

Correct Answer: C

Solution :

[c] Key Idea (i) Zn dust converts —OH group into—H.

(ii) Reaction with \[RX+{{H}_{2}}\xrightarrow[{}]{{}}RH+HX\] in presence of anhy.

\[RX+Mg\xrightarrow[{}]{{}}RMgX\] is called Friedel—Craft's alkylation.

(iii) Alkaline \[\text{mo}{{\text{l}}^{\text{-1}}}\] converts complete carbon chain which is directly attached with benzene ring, into -COOH group.