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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
Illustrate the following reaction giving suitable example in each case:Gabriel phthalimide synthesis
Accomplish the following conversion:
Nitrobenzene to benzoic acid
Accomplish the following conversion:
Benzyl chloride to 2-phenylethanamine
Give the structure of A, B and C in the following reaction:
\[\ce{C6H5N2Cl ->[CuCN] A ->[H2O/H+] B ->[NH3][\Delta] C}\]
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 structure of A, B and C in the following reaction:
\[\ce{C6H5NO2 ->[Fe/HCl] A ->[NaNO2 + HCl][273 K] B ->[H2O/H+][\Delta] C}\]
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.
Explain the mechanism of action of hydroiodic acid on 3-methylbutan-2-ol.
Identify 'A' and 'B' in the following reaction and rewrite the complete reaction :
Arrange the following in the increasing order of their pKb values:
C6H5NH2, C2H5NH2, C6H5NHCH3
Account for the following:
Gabriel phthalimide synthesis is not preferred for preparing aromatic primary amines.
Answer the following
Identify A and B in the following reactions.
\[\ce{C6H5CH2Br->[alco.][KCN]A ->[Na/ethanol]B.}\]
Answer the following
Explain the ammonolysis of alkyl halides.
Write reactions to bring about the following conversions.
Acetamide to methylamine
Write reactions for the preparation of ethanamine using Gabriel phthalimide synthesis.
Explain the following reaction with a suitable example.
Hofmann elimination reaction
Identify the product 'A' in the following reaction.
\[\ce{Aniline ->[(CH3CO)2O][Pyridine] A}\]
Alkyl cyanides on reduction by sodium and ethanol give primary amines. This reaction is called as ____________.
Identify the product obtained, when benzamide is treated with bromine and aqueous sodium hydroxide.
Which of the following amines exhibits maximum degree of intermolecular hydrogen bonding?
Identify the major product (B).
Which nitrogen containing compound amongst the following would undergo Mendius reduction to furnish primary amine \[\ce{(R - NH2)}\]?
Which of the following reagents is used in Mendius reduction reaction of alkyl cyanide?
Which of the following compounds is obtained when quaternary ammonium hydroxide is strongly heated?
Which of the following does NOT give carbylamine test?
For producing amines, the reaction of nitro compounds with iron scrap is preferred because:
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 ______.
Amongst the given set of reactants, the most appropriate for preparing 2° amine is ______.
The best reagent for converting 2–phenylpropanamide into 2-phenylpropanamine is ______.
Reduction of aromatic nitro compounds using \[\ce{Fe}\] and \[\ce{HCl}\] gives ______.
Reduction of nitrobenzene by which of the following reagent gives aniline?
(i) \[\ce{Sn/HCl}\]
(ii) \[\ce{Fe/HCl}\]
(iii) \[\ce{H2 - Pd}\]
(iv) \[\ce{Sn/NH4OH}\]
The reagents that can be used to convert benzenediazonium chloride to benzene are:
(i) \[\ce{SnCl2/HCl}\]
(ii) \[\ce{CH3CH2OH}\]
(iii) \[\ce{H3PO2}\]
(iv) \[\ce{LiAlH4}\]
Write following conversions:
nitrobenzene `->` acetanilide
How will you bring out the following conversion?
How will you carry out the following conversion?
How will you carry out the following conversions?
How will you carry out the following conversions?
Assertion: Hoffmann’s bromamide reaction is given by primary amines.
Reason: Primary amines are more basic than secondary amines.
Describe Gabriel's phthalimide synthesis. (Give reaction)
Account for the following:
Aniline cannot be prepared by the ammonolysis of chlorobenzene under normal conditions.
In the given reaction what is the X?
\[\begin{array}{cc}
\ce{O}\phantom{.......................}\\
||\phantom{.......................}\\
\phantom{}\ce{R - C - OH <-[H3O] Χ ->[H] RCH2NH2}
\end{array}\]
Acetamide and ethyl amide can be distinguished by reacting with.
Which of the following compound is expected to be most basic?
Which of the following CANNOT be prepared by ammonolysis of alkyl halide?
A compound 'A' on reduction with iron scrap and hydrochloric acid gives compound 'B' with molecular formula C6H7N. Compound 'B' on reaction with CHCl3 and alcoholic KOH produces an obnoxious smell of carbylamine due to the formation of 'C'. Identify 'A', 'B' and 'C' and write the chemical reactions involved.
Which of the following reaction DOES NOT involve Hoffmann bromamide degradation?
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.
Amides can be converted into amines by the reaction named ______.
Write short note on the following:
Ammonolysis
Identify A and B in the following reaction.
\[\ce{C6H5CH2Br ->[Alco.][KCN] A ->[Na/Ethanol][reduction] B}\]
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 a short note on the following:
Ammonolysis
