Advertisements
Advertisements
Question
Explain the following reaction with a suitable example.
Hofmann elimination reaction
Advertisements
Solution
- When tetraalkylammonium halide is heated with moist silver oxide, it gives quaternary ammonium hydroxide.
- Quaternary ammonium hydroxides on strong heating undergo β-elimination to give an alkene. This reaction is called Hofmann elimination.
- The least substituted alkene is obtained as a major product (in contrast to Saytzeff elimination).
e.g. Hofmann elimination reaction of N, N, N-Triethylpropylammonium iodide
APPEARS IN
RELATED QUESTIONS
How is ethyl amine prepared from methyl iodide?
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 :
How do you convert the following: Ethanenitrile to ethanamine
Give the structures of A, B and C in the following reactions :
Give the structure of A, B and C in the following reaction:
\[\ce{CH3CH2I ->[NaCN] A ->[OH-][Partial hydrolysis] B ->[NaOH + Br2] C}\]
Give the structures of A, B and C in the following reaction:
\[\ce{CH3COOH ->[NH3][\Delta] A ->[NaOBr] B ->[NaNO2/HCl] C}\]
Give a plausible explanation for the following:
Why are amines less acidic than alcohols of comparable molecular masses?
Identify 'A' and 'B' in the following reaction and rewrite the complete reaction :
Arrange the following in the increasing order of their pKb values:
C6H5NH2, C2H5NH2, C6H5NHCH3
Give the structures of A, B and C in the following reactions :
Choose the most correct option.
Which of the following compounds will dissolve in aqueous NaOH after undergoing reaction with Hinsberg reagent?
Acetamide on reduction using Na/C2H5OH gives ____________.
Identify the major product (B).
What product is formed when \[\ce{R - C ≡ N}\] is hydrolysed?
\[\ce{CH3-CN ->[Na/C2H5OH]}\]
The product formed is ____________.
Which of the following amines forms a clear solution when treated with benzene sulphonyl chloride and excess of potassium hydroxide?
Identify 'A' and 'B' in the following conversions.
\[\ce{CH3 - I ->[Alc. KCN][\Delta] A ->[Na/C2H5OH] B}\]
Identify the INCORRECT statement regarding Hofmann bromamide reaction.
Which of the following reagents is used in Mendius reduction reaction of alkyl cyanide?
Which of the following amines cannot be prepared by Gabriel phthalimide synthesis?
Amongst the following, the strongest base in aqueous medium is ______.
Which of the following reagents would not be a good choice for reducing an aryl nitro compound to an amine?
The source of nitrogen in Gabriel synthesis of amines is ______.
Amongst the given set of reactants, the most appropriate for preparing 2° amine is ______.
Best method for preparing primary amines from alkyl halides without changing the number of carbon atoms in the chain is ______.
Which of the following compounds is the weakest Brönsted base?
Among the following amines, the strongest Brönsted base is:
Which of the following methods of preparation of amines will give same number of carbon atoms in the chain of amines as in the reactant?
Reduction of nitrobenzene by which of the following reagent gives aniline?
(i) \[\ce{Sn/HCl}\]
(ii) \[\ce{Fe/HCl}\]
(iii) \[\ce{H2 - Pd}\]
(iv) \[\ce{Sn/NH4OH}\]
What is the best reagent to convert nitrile to primary amine?
Identify A and B in the following reaction.
How will you carry out the following conversion?
How will you carry out the following conversion?
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 \[\ce{NH3}\] |
Describe Gabriel's phthalimide synthesis. (Give reaction)
The Gabriels' phthalimide synthesis is used in the synthesis of
A primary amine is formed by an amide on treatment with bromine and alkali. The primary amine has
Which of the following reactions will not give a primary amine?
Reduction of nitro alkanes yields which compound?
In the given reaction what is the X?
\[\begin{array}{cc}
\ce{O}\phantom{.......................}\\
||\phantom{.......................}\\
\phantom{}\ce{R - C - OH <-[H3O] Χ ->[H] RCH2NH2}
\end{array}\]
Acetamide and ethyl amide can be distinguished by reacting with.
Which of the following compound is expected to be most basic?
C6H5CONHCH3 can be converted into C6H5CH2NHCH3 by:-
Which of the following CANNOT be prepared by ammonolysis of alkyl halide?
Give reasons for the following:
Ammonolysis of alkyl halides is not a good method to prepare pure primary amines.
Which of the following reaction DOES NOT involve Hoffmann bromamide degradation?
What is the IUPAC name of \[\ce{(CH3)2 - N - CH3}\]?
Identify the product ‘C’ in the following reaction.
\[\ce{Aniline ->[(CH3CH)2O][Pyridine] A ->[Br2][CH3COOH] B ->[H^+ or OH^-] C}\]
Write the name of the product formed by the action of LiAlH4/ether on acetamide.
Which of the following would not be a good choice for reducing nitrobenzene to aniline?
Write short note on the following:
Ammonolysis
Write a short note on the following:
Ammonolysis
Write a short note on the following:
Ammonolysis
Assertion: Amimonolysis of alkyl halides involves the reaction between alkyl halides and alcoholic ammonia.
Reason: Ammonolysis of alkyl halides produces secondary amines only.
