Which of the following statement is incorrect about the reaction of ammonia derivatives with carbonyl compounds?

Options

A. pH of solution is maintained between 3 to 4
B. Addition of ammonia derivatives occurs followed by elimination of `H_(2)O`
C. At very low pH (less than 3) ammonia derivatives are protonated and do not act as nucleophile
D. At very high pH reaction becomes explosive

Answer

To determine which statement is incorrect regarding the reaction of ammonia derivatives with carbonyl compounds, we need to analyze the behavior of these compounds under different pH conditions. Here’s a step-by-step breakdown:

### Step 1: Understanding the Reaction
- Ammonia derivatives (like primary amines) react with carbonyl compounds (like aldehydes and ketones) to form imines or enamines.
- The reaction involves nucleophilic attack by the nitrogen of the ammonia derivative on the electrophilic carbon of the carbonyl group.

**Hint:** Remember that the carbonyl carbon is electrophilic due to the electronegativity of oxygen.

### Step 2: Role of pH
- The pH of the reaction medium is crucial. A pH between 3 and 4 is optimal for the reaction.
- At low pH (less than 3), the ammonia derivative can become protonated, losing its nucleophilicity.
- At high pH (greater than 4), the medium becomes basic, allowing other nucleophiles to react before the ammonia derivative.

**Hint:** Consider how protonation affects the nucleophilicity of the ammonia derivative.

### Step 3: Evaluating Statements
1. **Statement about pH being maintained between 3 and 4:** This is correct because it ensures that the ammonia derivative remains nucleophilic.
2. **Statement about addition of ammonia derivative followed by elimination of water:** This is also correct as the reaction typically involves the formation of a tetrahedral intermediate that loses water.
3. **Statement about low pH causing protonation of ammonia derivative:** This is correct since protonation would inhibit nucleophilic attack.
4. **Statement about high pH causing the reaction to become explosive:** This is the incorrect statement. While high pH can lead to competitive reactions, it does not typically cause the reaction to become explosive.

**Hint:** Analyze each statement in the context of how pH affects the reaction mechanism.

### Conclusion
The incorrect statement is the one that claims the reaction becomes explosive at very high pH.

### Final Answer
The incorrect statement about the reaction of ammonia derivatives with carbonyl compounds is: "At very high pH, the reaction becomes explosive."