Question

Number of amine compounds from the following giving solids which are soluble in NaOH upon reaction with Hinsberg's reagent is _____.

Answer 1

Correct Answer: 5

To solve the problem of identifying the number of amine compounds that form solids soluble in NaOH when reacting with Hinsberg's reagent, follow these steps:

1. Understand Hinsberg's Test: This test differentiates primary, secondary, and tertiary amines.
   • Primary amines react with Hinsberg's reagent to form sulfonamide, which is soluble in alkali such as NaOH.
   • Secondary amines form a sulfonamide that is usually not soluble in NaOH.
   • Tertiary amines do not react with Hinsberg's reagent.
2. Identify Types of Amines: Review the provided amine structures.
   • Analyze each structure to determine if the nitrogen atom is connected to one, two, or three carbon-containing groups.
3. Determine Solubility in NaOH: Focus on primary amines.
   • Structure 1 (aniline derivative) - Primary amine
   • Structure 2 (benzylamine group) - Primary amine
   • Structure 5 (aliphatic primary amine) - Primary amine
   • Structure 8 (another aniline derivative) - Primary amine
   • Structure 9 (cyclohexylamine) - Primary amine
4. Count Primary Amines: Total number of primary amines: 5
5. Validate Solution: Ensure the answer falls within the given range of 5,5.

Since the calculated number is 5, it matches the expected range.

Therefore, the number of primary amine compounds that form solids soluble in NaOH with Hinsberg's reagent is 5.

Answer 2

Primary amines react with Hinsberg’s reagent to form sulphonamides, which are soluble in NaOH. Analyzing the given structures:
Primary amine NH$_2$: Soluble.
NH-C($-$CH$_3$): Soluble.
Other primary amine structures: Soluble.
All 5 compounds are primary amines.
Final Answer:
\[5.\]