Question

The IUPAC name of ${\text{C}}{{\text{H}}_3} - {\text{NH}} - {({\text{C}}{{\text{H}}_2})_6} - {\text{NH}} - {\text{C}}{{\text{H}}_3}$ is:
A.N, N – dimethyl hexylamine
B.N – methyl, methyl hexylamine
C.N, N – dimethyl – 1,6 - hexanediamine
D.None of the above

Answer 1

To write the IUPAC name follow the nomenclature given by IUPAC. The name will contain a similar number of carbon as prefix as in the given molecule. The functional group used here is amine and N is used to define the group attached with nitrogen atoms. For each different nitrogen atom we use dash as superscript to distinguish.

Complete step by step answer:
Let us first count the number of carbon atoms in the parent chain. Parent chain is that chain that contains the maximum possible number of carbon. The two methyl groups attached with each of the nitrogen will not be counted in the parent chain because they are the part of the functional group.
Hence the number of carbon is 6 and for 6 carbon atoms we use the suffix ‘hex’. Since it is an alkyl group we will call it hexyl.
Since two methyl groups are there and that too on different nitrogen so we will it as,
N, N – dimethyl.
Amine functional group is ${\text{N}}{{\text{H}}_2}$ and in the question secondary amine is given to us in which one hydrogen atom is replaced with any alkyl group. The name of the functional group will still be the same that is amine. To specify the position of the alkyl group we put the number of carbon to which it is attached. In our case it is attached to the first and the sixth Carbon.
Functional group is written at the end and the substituent is written at first. Amine is a functional group whereas methyl is a side substituent. Hence combining the above we will get the IUPAC name as:
N, N– dimethyl – 1,6 – hexanediamine

Thus, the correct option is C.

Note:
IUPAC stands for international union for pure and applied chemistry. The nomenclature has been set up by IUPAC so that all the compounds can be named under a standard set of rules and is acceptable worldwide.