IUPAC name of the compound
`C_2 H_5 - NH-CH_3` is___________.

Options

A. N-Ethylmethanamine
B. N-Methylethanamine
C. N-Methylmethanamine
D. Ethyl methylamine

Answer

To determine the IUPAC name of the compound \( C_2H_5 - NH - CH_3 \), we will follow these steps:

### Step 1: Identify the Longest Carbon Chain
The compound consists of an ethyl group (\( C_2H_5 \)) and a methyl group (\( CH_3 \)) attached to a nitrogen atom. The longest carbon chain that includes the functional group (amine in this case) is the ethyl group.

### Step 2: Identify the Functional Group
The functional group present in this compound is the amine group (\( -NH- \)). Since the longest chain is ethyl, we will consider it as the base name.

### Step 3: Determine the Base Name
The base name for the compound is derived from the longest carbon chain, which is ethane. Since we have an amine, we will use "ethanamine" as the base name.

### Step 4: Identify and Name the Substituents
The methyl group (\( CH_3 \)) is attached to the nitrogen atom. In IUPAC naming, when a substituent is attached to the nitrogen, we denote it as "N-" followed by the name of the substituent. Therefore, the methyl group will be named as "N-methyl".

### Step 5: Combine the Names
Now, we combine the names of the base chain and the substituent. The full IUPAC name of the compound is "N-methyl ethanamine".

### Final Answer
The IUPAC name of the compound \( C_2H_5 - NH - CH_3 \) is **N-methyl ethanamine**.

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