The positive carbylamine test is not given by

Options

A. anilinie
B. `2,4-` dimethyl aniline
C. `N-` methyl `-O-` methyline
D. `p-` methyl benzylamine

Explanation

To determine which compound does not give a positive carbylamine test, we need to understand the requirements for this test. The carbylamine test is specific for primary amines, which react with chloroform (CHCl3) and a strong base (usually NaOH) to form an isocyanide (carbylamine).

### Step-by-Step Solution:

1. **Understand the Carbylamine Test**:
- The carbylamine test is a qualitative test used to identify primary amines. When a primary amine reacts with chloroform and a strong base, it produces an isocyanide, which has a characteristic foul smell.

2. **Identify the Structure of Each Compound**:
- **Option 1: Aniline (C6H5NH2)**:
- Aniline is a primary amine (1° amine) because it has one alkyl group (the phenyl group) attached to the nitrogen atom.
- Therefore, it will give a positive carbylamine test.

- **Option 2: 2,4-Dimethylaniline**:
- This compound is also a primary amine, as it has two methyl groups attached to the benzene ring but still has only one alkyl group connected to the nitrogen.
- Thus, it will also give a positive carbylamine test.

- **Option 3: N-Methyl-ortho-methylaniline**:
- This compound is a secondary amine (2° amine) because it has two alkyl groups (one methyl and one methylene) attached to the nitrogen atom.
- Secondary amines do not give a positive carbylamine test.

- **Option 4: Para-methylbenzylamine**:
- This compound is a primary amine since it has a benzyl group (C6H5CH2-) attached to the nitrogen.
- Therefore, it will give a positive carbylamine test.

3. **Conclusion**:
- The only compound that does not give a positive carbylamine test is **N-Methyl-ortho-methylaniline**, which is a secondary amine.

### Final Answer:
The positive carbylamine test is not given by **N-Methyl-ortho-methylaniline**.