Question

The increasing order of reactivity of the following compounds towards reaction with alkyl halides directly is :
(A)(B)(C)
(D)
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• A. $\text{(B)<(A)<(C)<(D)}$
• B. $\text{(A)<(B)<(C)<(D)}$
• C. $\text{(B)<(A)<(D)<(C)}$
• D. $\text{(A)<(C)<(D)<(B)}$

Answer 1

The correct option is A $\text{(B)<(A)<(C)<(D)}$

Nucleophilicity order

For the reaction of a compound with alkyl halide directly, it should be a nucleophile.
Nucleophiles are the compound which have excess of electron and are electron donating group.
The lone pair pair of electrons on N of compound A and B is delocalised with the carbonyl group to form resonating structures.Hence, they are less basic/nucleophilic than C and D.

Since, in compound B, lone pair is delocalised between two carbonyl group, it is least basic/nucleophilic than others.

Also, in compound C, the electron withdrawing group, CN reduce the electron density on N.

In compound (d), lone pair is delocalised in benzene ring but it is readily available for nucleophilic reaction compare to others.

Hence, correct nucleophilic order is
$B<A<C<D$

Hence, option (b) is correct