English

Explain the following reaction with a suitable example. Hofmann elimination reaction - Chemistry

Advertisements
Advertisements

Question

Explain the following reaction with a suitable example.

Hofmann elimination reaction

Long Answer
Advertisements

Solution

  1. When tetraalkylammonium halide is heated with moist silver oxide, it gives quaternary ammonium hydroxide.
  2. Quaternary ammonium hydroxides on strong heating undergo β-elimination to give an alkene. This reaction is called Hofmann elimination.
  3. 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
shaalaa.com
  Is there an error in this question or solution?
Chapter 13: Amines - Long answer questions

APPEARS IN

SCERT Maharashtra Chemistry [English] 12 Standard HSC
Chapter 13 Amines
Long answer questions | Q 3.3

RELATED QUESTIONS

Write the chemical equation involved in the following reaction:

Hoffmann-bromamide degradation reaction


How do you convert the following: Ethanenitrile to ethanamine


Write a short note on the following:

Hoffmann’s bromamide reaction


Accomplish the following conversion:

Nitrobenzene to benzoic acid


Accomplish the following conversion:

Benzyl chloride to 2-phenylethanamine


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 structures of A, B and C in the following reaction:

\[\ce{CH3COOH ->[NH3][\Delta] A ->[NaOBr] B ->[NaNO2/HCl] C}\]


Write the reaction of aliphatic primary amine with nitrous acid.


Give a plausible explanation for the following:

Why are amines less acidic than alcohols of comparable molecular masses?


Mention 'two' uses of propan-2-one.


Give the structures of A, B and C in the following reactions :


 Write structures of compounds A and B in each of the following reactions:


Answer in one sentence.

Predict the product of the following reaction.

\[\ce{Nitrobenzene ->[Sn/conc.HCl]?}\]


Answer the following

Explain the ammonolysis of alkyl halides.


Write reactions to prepare ethanamine from Acetonitrile.


Name the process of breaking C-X bond by ammonia in preparation of amines.


Write reactions to bring about the following conversions.

Acetamide to Ethylamine


Why cannot aniline be prepared by Gabriel phthalimide synthesis?


Identify compound 'B' in following series of reactions?

\[\ce{Acetonitrile ->[Na/alcohol] A ->[NaNO2/dil.HCI] B}\]


Alkyl cyanides on reduction by sodium and ethanol give primary amines. This reaction is called as ____________.


Which of the following amines exhibits maximum degree of intermolecular hydrogen bonding?


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.

\[\ce{CH3 - I ->[Alc. KCN][\Delta] A ->[Na/C2H5OH] B}\]


Which of the following reagents is used in Mendius reduction reaction of alkyl cyanide?


Identify product B in the following reaction.

\[\ce{Aniline ->[NaNO2][HCl] A ->[KI] B}\]


Which of the following compounds is obtained when quaternary ammonium hydroxide is strongly heated?


Which of the following does NOT give carbylamine test?


Which of the following reactions does NOT yield an amine?


For producing amines, the reaction of nitro compounds with iron scrap is preferred because:


Quaternary ammonium salt is formed:


Given below are two statements labelled as Assertion (A) and Reason (R).

Assertion (A): Alkyl halides are insoluble in water.

Reason (R): Alkyl halides have halogen attached to sp3 hybrid carbon.

Select the most appropriate answer from the options given below:


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?


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) \[\ce{Sn/NH4OH}\]


Under which of the following reaction conditions, aniline gives p-nitro derivative as the major product?

(i) Acetyl chloride/pyridine followed by reaction with conc.\[\ce{H2SO4 }\] + conc. \[\ce{HNO3}\].

(ii) Acetic anyhdride/pyridine followed by conc.\[\ce{H2SO4}\] + conc.\[\ce{HNO3}\].

(iii) Dil. HCl followed by reaction with conc.\[\ce{H2SO4}\] + conc.\[\ce{HNO3}\].

(iv) Reaction with conc.\[\ce{HNO3}\] + conc.\[\ce{H2 SO4}\].


Suggest a route by which the following conversion can be accomplished.


Write following conversions:

nitrobenzene `->` acetanilide


Ethylamine can be prepared by the action of bromine and caustic potash on which compound?


Reduction of nitro alkanes yields which compound?


C6H5CONHCH3 can be converted into C6H5CH2NHCH3 by:-


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?


Methyl amine on reaction with chloroform in the presence of NaOH gives ______.


Which of the following statement(s) is/are incorrect in case of Hofmann bromamide degradation?


What is the IUPAC name of \[\ce{(CH3)2 - N - CH3}\]?


Identify the product ‘C’ in the following reaction.

\[\ce{Aniline ->[(CH3CH)2O][Pyridine] A ->[Br2][CH3COOH] B ->[H^+ or OH^-] C}\]


Identify A and B in the following reaction.

\[\ce{C6H5CH2Br ->[Alco.][KCN] A ->[Na/Ethanol][reduction] B}\]


Write a short note on Ammonolysis.


Write a short note on the following:

Ammonolysis.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×