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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
\[\ce{R - CO - NH2 + 4NaOH + Br2 ->R - CH2 - NH2 + Na2CO3 + 2NaBr + 2H2O}\]
\[\ce{CH3 - CH2 - CO - NH2 + 4NaOH + 2NaBr + 2H2O->CH3 - CH2 - NH2 + Na2CO3 + 2NaBr + 2H2O}\]
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संबंधित प्रश्न
How do you convert the following: C6H5CONH2 to C6H5NH2
Accomplish the following conversion:
Benzamide to toluene
Give the structure of A, B and C in the following reaction:
\[\ce{C6H5N2Cl ->[CuCN] A ->[H2O/H+] B ->[NH3][\Delta] C}\]
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?
Write the reaction of aromatic primary amine with nitrous acid.
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?
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 in one sentence.
Predict the product of the following reaction.
\[\ce{Nitrobenzene ->[Sn/conc.HCl]?}\]
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.
Answer the following
Explain the ammonolysis of alkyl halides.
Write reactions to prepare ethanamine from Acetonitrile.
Write reactions to bring about the following conversions.
Acetamide to Ethylamine
Write reactions to bring about the following conversions.
Acetamide to methylamine
Explain Hoffmann’s exhaustive alkylation with suitable reactions.
Explain the following reaction with a suitable example.
Hofmann elimination reaction
Identify compound 'B' in following series of reactions?
\[\ce{Acetonitrile ->[Na/alcohol] A ->[NaNO2/dil.HCI] B}\]
Acetamide on reduction using Na/C2H5OH gives ____________.
Alkyl cyanides on reduction by sodium and ethanol give primary amines. This reaction is called as ____________.
Identify the product obtained when benzyl chloride undergoes ammonolysis in presence of excess ammonia followed by the reaction with two moles of methyl iodide.
____________ can be prepared exclusively by Gabriel phthalimide synthesis.
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, ____________.
Identify 'A' and 'B' in the following conversions.
\[\ce{CH3 - I ->[Alc. KCN][\Delta] A ->[Na/C2H5OH] B}\]
In aqueous phase the order of basic strength of alkylamine is ______.
Given below are two statements labelled as Assertion (A) and Reason (R).
Assertion (A): Alkyl halides are insoluble in water.
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 ______.
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 ______.
Reduction of aromatic nitro compounds using \[\ce{Fe}\] and \[\ce{HCl}\] gives ______.
Best method for preparing primary amines from alkyl halides without changing the number of carbon atoms in the chain is ______.
Which of the following methods of preparation of amines will give same number of carbon atoms in the chain of amines as in the reactant?
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
Which of the following reactions are correct?
(i)
(ii)
(iii)
(iv)
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 bring out the following conversion?
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.
The Gabriels' phthalimide synthesis is used in the synthesis of
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?
Ethylamine can be prepared by the action of bromine and caustic potash on which compound?
Reduction of nitro alkanes yields which compound?
Acetamide and ethyl amide can be distinguished by reacting with.
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?
The amine 'A' when treated with nitrous acid gives yellow oily substance. The amine A is ______.
Write the name of the product formed by the action of LiAlH4/ether on acetamide.
Write short note on the following:
Ammonolysis
Identify A and B in the following reaction.
\[\ce{C6H5CH2Br ->[Alco.][KCN] A ->[Na/Ethanol][reduction] B}\]
