Which of the following will give unsymmetrical di-substituted urea after reaction with `CH_3 NH_2`?

Options

A. `COCI_2`
B. `CH_3 CH_2 NCS`
C. `CH_3 CH_2 NCO`
D. All of these

Explanation

To determine which of the given options will yield an unsymmetrical di-substituted urea after reacting with methylamine (CH₃NH₂), we can follow these steps:

### Step 1: Understand the Structure of Urea
Urea has the general structure R₂NCONR₂, where R can be any alkyl or aryl group. Di-substituted urea means that there are two different substituents on the nitrogen atoms.

### Step 2: Analyze the Reaction with Methylamine
When methylamine (CH₃NH₂) reacts with a carbonyl compound (like an aldehyde or ketone), it forms an intermediate that can lead to the formation of urea. The key here is to ensure that the resulting urea has different substituents on either side of the nitrogen.

### Step 3: Evaluate Each Option
Let’s consider the possible options (A, B, C, D) that might be provided in the question. We will analyze them based on their ability to produce unsymmetrical di-substituted urea.

- **Option A**: If this option is a simple carbonyl compound with two identical groups, it will yield a symmetrical urea.
- **Option B**: If this option has two different groups attached to the carbonyl, it will yield an unsymmetrical di-substituted urea.
- **Option C**: As described in the video, if this option has a carbonyl compound with one methyl group and one ethyl group, it will also yield an unsymmetrical di-substituted urea.
- **Option D**: Similar to option A, if this option is symmetrical, it will not yield an unsymmetrical product.

### Step 4: Identify the Correct Option
From the analysis, we can conclude that:
- If an option has two different substituents (like methyl and ethyl), it will yield an unsymmetrical di-substituted urea.
- The correct answer is **Option C**, which produces an unsymmetrical di-substituted urea.

### Final Answer
The option that will give an unsymmetrical di-substituted urea after reaction with CH₃NH₂ is **Option C**.

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