Secondary amines react with aldehydes and ketones containing `alpha` -hydrogen to form .........

Explanation

To answer the question: "Secondary amines react with aldehydes and ketones containing alpha-hydrogen to form .........", we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Reactants**:
- Secondary amines (R2NH) and aldehydes or ketones (RCHO or R2C=O) that contain alpha-hydrogens (hydrogens attached to the carbon adjacent to the carbonyl group).

2. **Understand the Reaction**:
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