Aryl Halides and Phenols - Result Question 4
####5. Which of the following compounds reacts with ethyl magnesium bromide and also decolourises bromine water solution
(2019 Main, 11 Jan II) (a)
(c)
(b)
(d)
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Answer:
Correct Answer: 5. $(b, d)$
Solution:
- Ethyl magnesium bromide is a Grignard reagent (GR), it constitutes $C _2 H _5^{-}\left[C _2 H _5^{-} \stackrel{\oplus}{M} gBr\right.$ in ether/aprotic medium $]$ which can act as nucleophile as well as strong base. Bromine water $\left(Br _2 / H _2 O\right.$, red $)$ gets decolourised with phenol derivatives (option, c), anisole derivatives (option, b) etc., as $>C=C<$ is present outside the ring (aliphatic, not aromatic).
(a)
(b)
(d)
Et group can react but $\left(Br _2 / H _2 O\right)$ does not react
