Which of the following compound contains amide functional group ?

Options

A. `CH_3 CH_2 NH CH_3`
B. `CH_3 CH_2 - underset(O)underset(||)C - NH_2`
C. `CH_3 underset(NH_2)underset(|)(CH) COOH`
D. `CH_3 N (CH_3)_2`

Answer

To determine which compound contains an amide functional group, we first need to understand what an amide group is. An amide group consists of a carbonyl group (C=O) directly attached to a nitrogen atom (N), which is also bonded to two hydrogen atoms (NH2) or other groups. The general structure can be represented as R1C(=O)NR2R3, where R1 is a carbon-containing group, and R2 and R3 can be hydrogen or other carbon-containing groups.

Now, let's analyze the options provided:

1. **Option A**: The compound is given as CH3-CH2-NH2.
- Here, we see that there is no carbonyl group (C=O) present. Thus, this compound does not contain an amide group.

2. **Option B**: The compound is given as R-C(=O)-NH2.
- In this case, we can see that there is a carbonyl group (C=O) directly attached to a nitrogen atom (NH2). This is the structure of an amide. Therefore, this option contains an amide functional group.

3. **Option C**: The compound is given as CH3-COOH (which is acetic acid).
- This compound has a carboxylic acid functional group (COOH) and does not have the structure of an amide. Thus, this option does not contain an amide group.

4. **Option D**: The compound is given as CH3-CH3-NH.
- Here, we have nitrogen but no carbonyl group (C=O) present. Therefore, this compound does not contain an amide functional group.

After analyzing all the options, we conclude that **Option B** is the only compound that contains an amide functional group.

### Final Answer:
**Option B** contains the amide functional group.