Advertisements
Advertisements
Questions
Write a short note on Hoffmann bromamide degradation.
Explain Hoffmann bromamide degradation reaction
Advertisements
Solution 1
(a)Hoffmann Bromanide degradation
(1) The conversion of amides into amine in presence of bromine and alkali is known on Hoffmann degradation of amides.
(2) An important characteristic of this reaction is that on amine with one carbon less than those in the amide is formed.
(3) This reaction is an example of molecular rearrangement and involves migration of an alkyl or aryl group from the carbonyl carbon to this adjacent nitrogen atom.
Example:
Solution 2
Hoffmann bromamide reaction:
a) Primary amine can be prepared by reaction of amide with bromine and aqueous or
alcoholic sodium hydroxide.
eg. Ethanamine is prepared by reaction of propanamide with bromine and aqueous or
alcoholic sodium hydroxide.
b) This reaction is known as Hoffmann bromamide degradation. It involves molecular
rearrangement. An alkyl or aryl group migrates from the carbonyl carbon to the
adjacent nitrogen atom.
c) This reaction is useful for decreasing the length of carbon chain by one carbon atom.
RELATED QUESTIONS
Illustrate the following reaction giving suitable example in each case:Gabriel phthalimide synthesis
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 structures of A, B and C in the following reactions :
Accomplish the following conversion:
Benzyl chloride to 2-phenylethanamine
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 structures of A, B and C in the following reaction:
\[\ce{C6H5NO2 ->[Fe/HCl] A ->[HNO2][273 K] B ->[C6H5OH] C}\]
Why cannot aromatic primary amines be prepared by Gabriel phthalimide synthesis?
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?
Explain the mechanism of action of hydroiodic acid on 3-methylbutan-2-ol.
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.
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 methylamine
Why cannot aniline be prepared by Gabriel phthalimide synthesis?
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 nitrogen containing compound amongst the following would undergo Mendius reduction to furnish primary amine \[\ce{(R - NH2)}\]?
Identify the product obtained when benzamide is treated with bromine and aqueous sodium hydroxide?
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 does NOT give carbylamine test?
Quaternary ammonium salt is formed:
Which of the following reagents would not be a good choice for reducing an aryl nitro compound to an amine?
Amongst the given set of reactants, the most appropriate for preparing 2° amine is ______.
Among the following amines, the strongest Brönsted base is:
Which of the following amines can be prepared by Gabriel synthesis.
(i) Isobutyl amine
(ii) 2-Phenylethylamine
(iii) N-methylbenzylamine
(iv) Aniline
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.
Identify A and B in the following reaction.
Write following conversions:
nitrobenzene `->` acetanilide
How will you carry out the following conversion?
How will you carry out the following conversions?
Assertion: Only a small amount of \[\ce{HCl}\] is required in the reduction of nitro compounds with iron scrap and \[\ce{HCl}\] in the presence of steam.
Reason: \[\ce{FeCl2}\] formed gets hydrolysed to release \[\ce{HCl}\] during the reaction.
The Gabriels' phthalimide synthesis is used in the synthesis of
Reduction of nitro alkanes yields which compound?
Acetamide and ethyl amide can be distinguished by reacting with.
C6H5CONHCH3 can be converted into C6H5CH2NHCH3 by:-
Which of the following CANNOT be prepared by ammonolysis of alkyl halide?
- Phenyl methenamine
- N, N - Dimethylaniline
- N - Methyl aniline
- Benzenamine
Choose the correct order of the basic nature of the above amines.
Write short note on the following:
Ammonolysis
Identify the compo ds A and B in the following reactions:
\[\ce{A ->[Nitrating mixture] B ->[(i) Sn/cone. HCI][(ii) NaOH] Aniline}\]
Write short note on the following:
Ammonolysis
Write a short note on the following:
Ammonolysis
Write the name of reduction product formed when ethyl cyanide is treated with sodium and alcohol.
Write a short note on Ammonolysis.
Write short note on the following:
Ammonolysis
Write short note on the following.
Ammonolysis.
Write short notes on the following:
Ammonolysis
