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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.
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Hoffmann-bromamide degradation reaction
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\[\ce{C6H5CH2Br->[alco.][KCN]A ->[Na/ethanol]B.}\]
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Answer the following
Explain the ammonolysis of alkyl halides.
Write reactions to prepare ethanamine from Acetonitrile.
Why cannot aniline be prepared by Gabriel phthalimide synthesis?
Identify compound 'B' in following series of reactions?
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Which of the following amines exhibits maximum degree of intermolecular hydrogen bonding?
Identify the major product (B).
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What is the molar mass of the amine formed when acetamide undergoes Hofmann bromamide degradation?
\[\ce{CH3-CN ->[Na/C2H5OH]}\]
The product formed is ____________.
Which nitrogen containing compound amongst the following would undergo Mendius reduction to furnish primary amine \[\ce{(R - NH2)}\]?
Which of the following reactions is appropriate for converting benzamide to aniline?
Identify the product obtained when benzamide is treated with bromine and aqueous sodium hydroxide?
Identify 'A' and 'B' in the following conversions.
\[\ce{CH3 - I ->[Alc. KCN][\Delta] A ->[Na/C2H5OH] B}\]
Identify product B in the following reaction.
\[\ce{Aniline ->[NaNO2][HCl] A ->[KI] B}\]
Which of the following reactions does NOT yield an amine?
Nitro compounds are reduced by iron scrap and hydrochloric acid to yield one of the following compounds:
In order to prepare a 1° amine from an alkyl halide with simultaneous addition of one \[\ce{CH2}\] group in the carbon chain, the reagent used as source of nitrogen is ______.
The best reagent for converting, 2-phenylpropanamide into 1- phenylethanamine is ______.
Hoffmann Bromamide Degradation reaction is shown by ______.
Reduction of nitrobenzene by which of the following reagent gives aniline?
(i) \[\ce{Sn/HCl}\]
(ii) \[\ce{Fe/HCl}\]
(iii) \[\ce{H2 - Pd}\]
(iv) \[\ce{Sn/NH4OH}\]
Which of the following amines can be prepared by Gabriel synthesis.
(i) Isobutyl amine
(ii) 2-Phenylethylamine
(iii) N-methylbenzylamine
(iv) Aniline
Identify A and B in the following reaction.
Write following conversions:
acetanilide `->` p-nitroaniline
How will you bring out the following conversion?
How will you carry out the following conversions?
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Reason: Aryl halides undergo nucleophilic substitution with anion formed by phthalimide.
The Gabriels' phthalimide synthesis is used in the synthesis of
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The amine 'A' when treated with nitrous acid gives yellow oily substance. The amine A is ______.
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What is the IUPAC name of \[\ce{(CH3)2 - N - CH3}\]?
Identify the product ‘C’ in the following reaction.
\[\ce{Aniline ->[(CH3CH)2O][Pyridine] A ->[Br2][CH3COOH] B ->[H^+ or OH^-] C}\]
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Write short note on the following:
Ammonolysis
Identify A and B in the following reaction.
\[\ce{C6H5CH2Br ->[Alco.][KCN] A ->[Na/Ethanol][reduction] B}\]
Assertion: Amimonolysis of alkyl halides involves the reaction between alkyl halides and alcoholic ammonia.
Reason: Ammonolysis of alkyl halides produces secondary amines only.
Write a short note on the following:
Ammonolysis
