Advertisements
Advertisements
Question
Explain the following reaction with a suitable example.
Hofmann elimination reaction
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?
Write a short note on Hoffmann bromamide degradation.
Give the structures of A, B and C in the following reactions :
Accomplish the following conversion:
Benzamide to toluene
Give the structure of A, B and C in the following reaction:
\[\ce{CH3CH2Br ->[KCN] A ->[LiAlH4] B ->[HNO2][0^\circ C] C}\]
Give the structure of A, B and C in the following reaction:
\[\ce{C6H5NO2 ->[Fe/HCl] A ->[NaNO2 + HCl][273 K] B ->[H2O/H+][\Delta] C}\]
Give the structures of A, B and C in the following reaction:
Give plausible explanation for each of 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 :
Give the structures of A, B and C in the following reactions :
Give the structures of A, B and C in the following reactions :
Answer in one sentence.
Which amide does produce ethanamine by Hofmann bromamide degradation reaction?
Answer the following
Explain the ammonolysis of alkyl halides.
Write the order of reactivity of alkyl halides with ammonia.
Write reactions to bring about the following conversions.
Acetamide to Ethylamine
Write reactions to bring about the following conversions.
Acetamide to methylamine
Explain Hoffmann’s exhaustive alkylation with suitable reactions.
Why cannot aniline be prepared by Gabriel phthalimide synthesis?
Identify compound 'B' in following series of reactions?
\[\ce{Acetonitrile ->[Na/alcohol] A ->[NaNO2/dil.HCI] B}\]
Acetamide on reduction using Na/C2H5OH gives ____________.
Identify the product obtained when benzyl chloride undergoes ammonolysis in presence of excess ammonia followed by the reaction with two moles of methyl iodide.
Identify the major product (B).
____________ can be prepared exclusively by Gabriel phthalimide synthesis.
The reduction of alkyl cyanide with sodium and ethanol to give primary amines is, ____________.
In aqueous phase the order of basic strength of alkylamine is ______.
Which of the following reagents is used in Mendius reduction reaction of alkyl cyanide?
Which of the following compounds is obtained when quaternary ammonium hydroxide is strongly heated?
For producing amines, the reaction of nitro compounds with iron scrap is preferred because:
Benzylamine may be alkylated as shown in the following equation:
\[\ce{C6H5CH2NH2 + R - X -> C6H5CH2NHR}\]
Which of the following alkylhalides is best suited for this reaction through SN1 mechanism?
The source of nitrogen in Gabriel synthesis of amines is ______.
Reduction of aromatic nitro compounds using \[\ce{Fe}\] and \[\ce{HCl}\] gives ______.
Which of the following compounds is the weakest Brönsted base?
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?
The reagents that can be used to convert benzenediazonium chloride to benzene are:
(i) \[\ce{SnCl2/HCl}\]
(ii) \[\ce{CH3CH2OH}\]
(iii) \[\ce{H3PO2}\]
(iv) \[\ce{LiAlH4}\]
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)
What is the best reagent to convert nitrile to primary amine?
Write following conversions:
acetanilide `->` p-nitroaniline
How will you bring out the following conversion?
How will you carry out the following conversions?
Assertion: Hoffmann’s bromamide reaction is given by primary amines.
Reason: Primary amines are more basic than secondary amines.
The Gabriels' phthalimide synthesis is used in the synthesis of
Which of the following compound is expected to be most basic?
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.
Give reasons for the following:
Ammonolysis of alkyl halides is not a good method to prepare pure primary amines.
Identify the product ‘C’ in the following reaction.
\[\ce{Aniline ->[(CH3CH)2O][Pyridine] A ->[Br2][CH3COOH] B ->[H^+ or OH^-] C}\]
Which of the following would not be a good choice for reducing nitrobenzene to aniline?
Identify A and B in the following reaction.
\[\ce{C6H5CH2Br ->[Alco.][KCN] A ->[Na/Ethanol][reduction] B}\]
Write a short note on Ammonolysis.
Write short note on the following:
Ammonolysis
Write a short note on Ammonolysis.
Write a short note on the following:
Ammonolysis.
