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Questions
Write a short note on Hoffmann bromamide degradation.
Explain Hoffmann bromamide degradation reaction
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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
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Hoffmann-bromamide degradation reaction
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\[\ce{CH3-CN ->[Na/C2H5OH]}\]
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\[\ce{Aniline ->[NaNO2][HCl] A ->[KI] B}\]
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Nitro compounds are reduced by iron scrap and hydrochloric acid to yield one of the following compounds:
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:
Amongst the following, the strongest base in aqueous medium is ______.
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 \[\ce{HNO2}\]?
Suggest a route by which the following conversion can be accomplished.
How will you carry out the following conversion?
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 \[\ce{NH3}\] |
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Write a short note on the following:
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Ammonolysis.
Write a short note on the following:
Ammonolysis
