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प्रश्न
Why cannot aromatic primary amines be prepared by Gabriel phthalimide synthesis?
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उत्तर
Gabriel synthesis is used for the preparation of primary amines. Phthalimide, on treatment with ethanolic potassium hydroxide, forms potassium salt of phthalimide, which on heating with alkyl halide followed by alkaline hydrolysis produces the corresponding primary amine. Aromatic primary amines cannot be prepared by this method because aryl halides do not undergo nucleophilic substitution with the anion formed by phthalimide.
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संबंधित प्रश्न
An aromatic compound 'A' of molecular formula C7H7ON undergoes a series of reactions as shown below. Write the structures of A, B, C, D and E in the following reactions :
Give the structure of A, B and C in the following reaction:
\[\ce{CH3CH2I ->[NaCN] A ->[OH-][Partial hydrolysis] B ->[NaOH + Br2] C}\]
Explain Hoffmann’s exhaustive alkylation with suitable reactions.
The end product C of the following reaction is
\[\ce{C2H5NH2 ->[HNO2] A ->[PCl5] B ->[NH3][Alcohol] C}\]
Identify the major product (B).
What is the molar mass of the amine formed when acetamide undergoes Hofmann bromamide degradation?
Identify product B in the following reaction.
\[\ce{Aniline ->[NaNO2][HCl] A ->[KI] B}\]
For producing amines, the reaction of nitro compounds with iron scrap is preferred because:
The best reagent for converting, 2-phenylpropanamide into 1- phenylethanamine is ______.
Which of the following amines can be prepared by Gabriel synthesis.
(i) Isobutyl amine
(ii) 2-Phenylethylamine
(iii) N-methylbenzylamine
(iv) Aniline
Which of the following reactions are correct?
(i)
(ii)
(iii)
(iv)
How will you carry out the following conversions?
Match the reactions given in Column I with the statements given in Column II.
| Column I | Column II | ||
| (i) | Ammonolysis | (a) | Amine with lesser number of carbon atoms |
| (ii) | Gabriel phthalimide synthesis | (b) | Detection test for primary amines. |
| (iii) | Hoffmann Bromamide reaction | (c) | Reaction of phthalimide with \[\ce{KOH}\] and \[\ce{R-X}\] |
| (iv) | Carbylamine reaction | (d) | Reaction of alkylhalides with \[\ce{NH3}\] |
Reduction of nitro alkanes yields which compound?
In the given reaction what is the X?
\[\begin{array}{cc}
\ce{O}\phantom{.......................}\\
||\phantom{.......................}\\
\phantom{}\ce{R - C - OH <-[H3O] Χ ->[H] RCH2NH2}
\end{array}\]
Which of the following CANNOT be prepared by ammonolysis of alkyl halide?
A compound 'A' on reduction with iron scrap and hydrochloric acid gives compound 'B' with molecular formula C6H7N. Compound 'B' on reaction with CHCl3 and alcoholic KOH produces an obnoxious smell of carbylamine due to the formation of 'C'. Identify 'A', 'B' and 'C' and write the chemical reactions involved.
Which of the following amines can be prepared by Gabriel phthalimide reaction?
Write short note on the following:
Ammonolysis
Write a short note on Ammonolysis.
