Question

The ortho/para directing group among the following is:
A)$COOH$
B) $CN$
C)$COC{H_3}$.
D) $NHCOC{H_3}$

Answer 1

Hint: We know that Electrophilic replacement reaction as perhaps the most central substance measures is influenced by particles or gatherings previously appended to the sweet-smelling ring. The gatherings that advance replacement at the ortho/para or meta positions are, individually, called ortho/para and meta coordinating gatherings, which are regularly portrayed by their ability to give electrons to or pull out electrons from the ring. Ortho/para coordinating gatherings have most adverse charges on the ortho/para positions, while meta coordinating gatherings frequently have the biggest negative charge on the meta position.

Complete answer:
We know that an electron withdrawing group (EWG) will have the opposite impact on the nucleophilicity of the ring. The EWG eliminates electron thickness from a π framework, making it less receptive in this sort of reaction, and subsequently called deactivating groups.
Since the $CO$ group is present in $COOH$ and $COC{H_3}$ they are Meta directing groups. Hence, option A and C are incorrect. Likewise, $CN$ is also a Meta directing group hence option B is also incorrect. In option D there is a presence of multiple bonds hence it is an ortho/para directing group. Thus, option D is correct.

Note:
In an electrophilic replacement response, existing substituent groups on the sweet-smelling ring impact the general response rate or directing affect positional isomer of the items that are shaped. An electron giving gathering (EDG) or electron delivering group (ERG, Z in underlying recipes) is a particle or utilitarian gathering that gives a portion of its electron thickness into a formed \[\pi \] framework by means of reverberation (mesomerism) or inductive impacts (or acceptance)— called +M or +I impacts, individually—consequently making the π framework more nucleophilic because of these electronic impacts, a fragrant ring to which such a gathering is joined is bound to partake in electrophilic replacement response. EDGs are in this way frequently known as initiating gatherings, however steric impacts can meddle with the response.
An electron pulling out group (EWG) will have the contrary impact on the nucleophilicity of the ring. The EWG eliminates electron thickness from a \[\pi \] framework, making it less receptive in this sort of reaction, and subsequently called deactivating gatherings.