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प्रश्न
Explain the following reaction with a suitable example.
Hofmann elimination reaction
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उत्तर
- 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
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संबंधित प्रश्न
How are propan-1-amine and propan-2-amine prepared from oxime?
Identify the compounds 'A' and 'B' in the following equation:
Write the chemical equation involved in the following reaction:
Hoffmann-bromamide degradation reaction
Give the structure of A, B and C in the following reaction:
\[\ce{C6H5N2Cl ->[CuCN] A ->[H2O/H+] B ->[NH3][\Delta] C}\]
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:
\[\ce{C6H5NO2 ->[Fe/HCl] A ->[HNO2][273 K] B ->[C6H5OH] C}\]
Write the reaction of aromatic primary amine with nitrous acid.
Write the reaction of aliphatic primary amine with nitrous acid.
Explain the mechanism of action of hydroiodic acid on 3-methylbutan-2-ol.
Mention 'two' uses of propan-2-one.
Give the structures of A, B and C in the following reactions :
Account for the following:
Gabriel phthalimide synthesis is not preferred for preparing aromatic primary amines.
Choose the most correct option.
Which of the following compounds will dissolve in aqueous NaOH after undergoing reaction with Hinsberg reagent?
Write reactions to prepare ethanamine from Acetonitrile.
The following amines is the product of Gabriel phthalimide synthesis.
Why cannot aniline be prepared by Gabriel phthalimide synthesis?
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\[\ce{Aniline ->[(CH3CO)2O][Pyridine] A}\]
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).
Which of the following amines forms a clear solution when treated with benzene sulphonyl chloride and excess of potassium hydroxide?
The reduction of alkyl cyanide with sodium and ethanol to give primary amines is, ____________.
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Nitro compounds are reduced by iron scrap and hydrochloric acid to yield one of the following compounds:
For producing amines, the reaction of nitro compounds with iron scrap is preferred because:
Given below are two statements labelled as Assertion (A) and Reason (R).
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Reason (R): Alkyl halides have halogen attached to sp3 hybrid carbon.
Select the most appropriate answer from the options given below:
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\[\ce{C6H5CH2NH2 + R - X -> C6H5CH2NHR}\]
Which of the following alkylhalides is best suited for this reaction through SN1 mechanism?
Which of the following reagents would not be a good choice for reducing an aryl nitro compound to an amine?
The best reagent for converting 2–phenylpropanamide into 2-phenylpropanamine is ______.
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 product when \[\ce{C6H5CH2NH2}\] reacts with \[\ce{HNO2}\]?
What is the best reagent to convert nitrile to primary amine?
Suggest a route by which the following conversion can be accomplished.
Write following conversions:
acetanilide `->` p-nitroaniline
How will you bring out the following conversion?
Account for the following:
Aniline cannot be prepared by the ammonolysis of chlorobenzene under normal conditions.
The Gabriels' phthalimide synthesis is used in the synthesis of
Which of the following reactions will not give a primary amine?
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:-
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- Phenyl methenamine
- N, N - Dimethylaniline
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- Benzenamine
Choose the correct order of the basic nature of the above amines.
What is the IUPAC name of \[\ce{(CH3)2 - N - CH3}\]?
Write the name of the product formed by the action of LiAlH4/ether on acetamide.
Identify A and B in the following reaction.
\[\ce{C6H5CH2Br ->[Alco.][KCN] A ->[Na/Ethanol][reduction] B}\]
Write a short note on the following:
Ammonolysis
Write a short note on the following:
Ammonolysis.
