Question

$(RCO)_2NH$ is
A. Primary Amine
B. Secondary Amine
C. Secondary Amide
D. Tertiary Amide

Answer 1

Hint: Amides are organic compounds containing nitrogen atom. In amides nitrogen atom is attached to an acyl group (R-C=O). Basically, amide group is $R—CO—NH_2$ so when one hydrogen of ammonia is replaced by amide group, they can be called as derivative of ammonia $(NH_3)$.

Complete step by step solution: As we know the amide group is-









Here R can be any substituent like alkyl group, amide group, hydrogen, etc.
On the basis of the number of carbon groups attached to nitrogen, the amides are classified into three types.
1. Primary Amide


When only one hydrogen is replaced by the amide group it is called primary amide. The examples of primary amide are acetamide $(H_3C—CONH_2)$, benzamide $(C_6H_5—CONH_2)$
2. Secondary Amide


When the second hydrogen of attached to nitrogen is replaced by any alkyl, aryl, or amide group is called a secondary amide. The examples of secondary amides are acetamide $(C_2H_5—CONH—CH_3)$, N,N-dimethylformamide $(H—CON(CH_3)_2)$.

3. Tertiary Amide








When all Hydrogens connected to Nitrogen are replaced by carbon-containing groups they are called tertiary amides. The examples of tertiary amides are N,N-dimethylacetamide $(CH_3—CON(CH_3)_2)$, N,N-dimethylbenzamide $(C_6H_5—CON(CH_3)_2)$.
In $(RCO)_2NH$ two amide groups and one hydrogen is attached to the nitrogen, the structure of $(RCO)_2NH$ is given as:


Hence, it is a secondary amide.

Thus, Option (C) is correct

Note: When amide is a part of a protein it is called a peptide bond. Amides are important parts of several compounds like proteins, plastics, nylons, polymers, etc. To prepare amide, coupling of carboxylic acid and amine can be done. They are also prepared by Beckmann rearrangement and Schmidt reaction.