Question

The IUPAC name of

A. N-cyclohexyl benzamide
B. N-Phenyl-N-cyclohexylmethanamide

Answer 1

Hint: According to IUPAC (International Union of Pure and Applied Chemistry), whenever we are going to write the IUPAC name of a compound, we have to give numbering first to functional groups or highly substituted carbon. Means lower numbering should be comes to functional group or highly substituted carbon present in the molecule or compound

Complete Solution :
- In the question it is given to write the IUPAC name of the given compound.
- The structure of the given compound is as follows.

- We can write the above structure in an elaborate manner as follows.
 

- Means Amine is attached to a benzene ring and carbonyl functional group is attached to a cyclohexane ring.
- The functional group –CONH- together is called amide.
- Means to the amide functional group is hooked between benzene and cyclohexane rings.
- As we know the benzene is attached to nitrogen of the amide functional group and cyclohexane is attached to carbonyl of the amide functional group.
- We have to consider that cyclohexylmethanamide is attached to nitrogen and phenyl ring is attached to nitrogen to write the IUPAC name of the given compound.
- Then we can write N-Phenyl (benzene attached to nitrogen) and N-cyclohexylmethanamide.
- By combining both we will get N-Phenyl-N-cyclohexylmethanamide.
- Therefore the IUPAC of the given compound is N-Phenyl-N-cyclohexylmethanamide.
So, the correct answer is “Option B”.

Note: In case of cyclic rings the writing of IUPAC names is different when compared to aliphatic chains. We have to check through which functional group they are attached or through which atoms the cyclic rings are attached.