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प्रश्न
Write the chemical equation involved in the following reaction:
Hoffmann-bromamide degradation reaction
Illustrate the following reaction giving a suitable example in the case:
Hoffmann bromamide degradation reaction
Write the reactions involved in Hofmann bromamide degradation reaction
Write the chemical equation involved in Hoffmann Bromamide degradation for acetamide.
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उत्तर १
- Primary amine can be prepared by reaction of the amide with bromine and aqueous or alcoholic sodium hydroxide. 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.
- This reaction is useful for decreasing the length of carbon chain by one carbon atom.
\[\ce{CH3 - CO - NH2 + 4NaOH + Br2 ->CH3 - NH2 + Na2CO3 + 2NaBr + 2H2O}\]
उत्तर २
\[\ce{R - CO - NH2 + 4NaOH + Br2 ->R - CH2 - NH2 + Na2CO3 + 2NaBr + 2H2O}\]
\[\ce{CH3 - CH2 - CO - NH2 + 4NaOH + 2NaBr + 2H2O->CH3 - CH2 - NH2 + Na2CO3 + 2NaBr + 2H2O}\]
APPEARS IN
संबंधित प्रश्न
How is ethyl amine prepared from methyl iodide?
Write a short note on Hoffmann bromamide degradation.
Identify the compounds 'A' and 'B' in the following equation:
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 :
How do you convert the following: C6H5CONH2 to C6H5NH2
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:
\[\ce{CH3CH2I ->[NaCN] A ->[OH-][Partial hydrolysis] B ->[NaOH + Br2] C}\]
Give the structures of A, B and C in the following reaction:
\[\ce{CH3COOH ->[NH3][\Delta] A ->[NaOBr] B ->[NaNO2/HCl] C}\]
Why cannot aromatic primary amines be prepared by Gabriel phthalimide synthesis?
Give the structures of A, B and C in the following reactions :
Give the structures of A, B and C in the following reactions :
Choose the most correct option.
Which of the following compounds will dissolve in aqueous NaOH after undergoing reaction with Hinsberg reagent?
Answer in one sentence.
Which amide does produce ethanamine by Hofmann bromamide degradation reaction?
Answer the following
Identify A and B in the following reactions.
\[\ce{C6H5CH2Br->[alco.][KCN]A ->[Na/ethanol]B.}\]
Answer the following
Write a reaction to convert acetic acid into methylamine.
Write reactions to prepare ethanamine from Acetonitrile.
Write reactions to bring about the following conversions.
Acetamide to Ethylamine
Identify compound 'B' in following series of reactions?
\[\ce{Acetonitrile ->[Na/alcohol] A ->[NaNO2/dil.HCI] B}\]
Acetamide on reduction using Na/C2H5OH gives ____________.
Identify the product 'A' in the following reaction.
\[\ce{Aniline ->[(CH3CO)2O][Pyridine] A}\]
Identify the product obtained, when benzamide is treated with bromine and aqueous sodium hydroxide.
Identify the major product (B).
____________ can be prepared exclusively by Gabriel phthalimide synthesis.
\[\ce{CH3-CN ->[Na/C2H5OH]}\]
The product formed is ____________.
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 amines cannot be prepared by Gabriel phthalimide synthesis?
Identify product B in the following reaction.
\[\ce{Aniline ->[NaNO2][HCl] A ->[KI] B}\]
Which of the following does NOT give carbylamine test?
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:
Quaternary ammonium salt is formed:
Benzylamine may be alkylated as shown in the following equation:
\[\ce{C6H5CH2NH2 + R - X -> C6H5CH2NHR}\]
Which of the following alkylhalides is best suited for this reaction through SN1 mechanism?
The source of nitrogen in Gabriel synthesis of amines is ______.
Hoffmann Bromamide Degradation reaction is shown by ______.
Reduction of aromatic nitro compounds using \[\ce{Fe}\] and \[\ce{HCl}\] gives ______.
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
Which of the following reactions are correct?
(i)
(ii)
(iii)
(iv)
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.\[\ce{H2 SO4}\].
What is the best reagent to convert nitrile to primary amine?
Suggest a route by which the following conversion can be accomplished.
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.
Assertion: Aromatic 1° amines can be prepared by Gabriel Phthalimide Synthesis.
Reason: Aryl halides undergo nucleophilic substitution with anion formed by phthalimide.
A primary amine is formed by an amide on treatment with bromine and alkali. The primary amine has
Which of the following reactions will not give a primary amine?
The compound X is which of the following?
\[\ce{CH3CN ->[Na + C2H5OH] x}\]
Reduction of nitro alkanes yields which compound?
In the given reaction what is the X?
\[\begin{array}{cc}
\ce{O}\phantom{.......................}\\
||\phantom{.......................}\\
\phantom{}\ce{R - C - OH <-[H3O] Χ ->[H] RCH2NH2}
\end{array}\]
Which of the following compound is expected to be most basic?
Give reasons for the following:
Ammonolysis of alkyl halides is not a good method to prepare pure primary amines.
Which of the following compound gives pink colour on reaction with phthalic anhydride in cone. H2SO4 followed by treatment with NaOH?
Which of the following reaction DOES NOT involve Hoffmann bromamide degradation?
Which of the following amines can be prepared by Gabriel phthalimide reaction?
Which of the following would not be a good choice for reducing nitrobenzene to aniline?
Amides can be converted into amines by the reaction named ______.
Write short note on the following:
Ammonolysis
Assertion: Amimonolysis of alkyl halides involves the reaction between alkyl halides and alcoholic ammonia.
Reason: Ammonolysis of alkyl halides produces secondary amines only.
Write short notes on the following:
Ammonolysis
