Question

Which of the following amino compound(s) CANNOT be prepared by Gabriel phthalimide synthesis? 

(A) n-Butylamine 
(B) Alanine 
(C) Aniline 
(D) t-Butylamine 
Choose the correct answer from the options given below:

• A. (B) and (D) only
• B. (C) and (D) only
• C. (A) and (B) only
• D. (B), (C) and (D) only

Hint:

Gabriel phthalimide synthesis is effective for primary amines, but aromatic and bulky amines are not readily formed by this method.

Answer 1

The Correct Option is D

Step 1: Gabriel Phthalimide Synthesis Overview.
Gabriel phthalimide synthesis is a method used to prepare primary amines by reacting phthalimide with an alkyl halide in the presence of a strong base, followed by hydrolysis. This synthesis is typically effective for the preparation of primary amines, but there are limitations.

Step 2: Analysis of Options.
- (A) n-Butylamine: n-Butylamine can be easily synthesized using Gabriel phthalimide synthesis as the alkylation step proceeds with primary alkyl halides.
- (B) Alanine: Alanine contains both an amino group and a carboxyl group, which complicates its synthesis via Gabriel phthalimide, as it involves a secondary amino group. Thus, alanine cannot be synthesized via this method.
- (C) Aniline: Aniline is an aromatic amine, and Gabriel phthalimide is not effective for preparing aromatic amines like aniline. Hence, aniline cannot be prepared by this method.
- (D) t-Butylamine: t-Butylamine involves a bulky tertiary-butyl group, which also prevents the alkylation step from proceeding effectively in the Gabriel synthesis. Thus, t-butylamine cannot be synthesized by this method.

Step 3: Conclusion.
Therefore, the correct answer is (4) (B), (C) and (D) as these compounds cannot be prepared by Gabriel phthalimide synthesis.

Final Answer: \[ \boxed{\text{(4) (B), (C) and (D) only}} \]