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प्रश्न
Write a short note on the following:
Hoffmann’s bromamide reaction
उत्तर
Hoffmann developed a method for preparation of primary amines by treating an amide with bromine in an aqueous or ethanolic solution of sodium hydroxide. In this degradation reaction, migration of an alkyl or aryl group takes place from carbonyl carbon of the amide to the nitrogen atom. The amine so formed contains one carbon less than that present in the amide.
\[\begin{array}{cc}
\ce{O}\phantom{.............................................................}\\
||\phantom{.............................................................}\\
\ce{R - C - NH2 + Br2 + 4NaOH -> R - NH2 + Na2CO3 + 2NaBr + 2H2O}
\end{array}\]
APPEARS IN
संबंधित प्रश्न
Identify the compounds 'A' and 'B' in the following equation:
Write the chemical equation involved in the following reaction:
Hoffmann-bromamide degradation reaction
Illustrate the following reaction giving suitable example in each case:Gabriel phthalimide synthesis
Write the reactions of aromatic with nitrous acid.
Give plausible explanation for each of the following :
Why are amines less acidic than alcohols of comparable molecular masses?
Choose the most correct option.
Which of the following compounds will dissolve in aqueous NaOH after undergoing reaction with Hinsberg reagent?
Answer the following
Explain the ammonolysis of alkyl halides.
Explain Hoffmann’s exhaustive alkylation with suitable reactions.
The end product C of the following reaction is
\[\ce{C2H5NH2 ->[HNO2] A ->[PCl5] B ->[NH3][Alcohol] C}\]
Which of the following reagents would not be a good choice for reducing an aryl nitro compound to an amine?
Reduction of aromatic nitro compounds using \[\ce{Fe}\] and \[\ce{HCl}\] gives ______.
Which of the following compounds is the weakest Brönsted base?
Reduction of nitrobenzene by which of the following reagent gives aniline?
(i) \[\ce{Sn/HCl}\]
(ii) \[\ce{Fe/HCl}\]
(iii) \[\ce{H2 - Pd}\]
(iv) \[\ce{Sn/NH4OH}\]
What is the product when \[\ce{C6H5CH2NH2}\] reacts with \[\ce{HNO2}\]?
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.
Ethylamine can be prepared by the action of bromine and caustic potash on which compound?
Give reasons for the following:
Ammonolysis of alkyl halides is not a good method to prepare pure primary amines.
What is the IUPAC name of \[\ce{(CH3)2 - N - CH3}\]?
Identify the compo ds A and B in the following reactions:
\[\ce{A ->[Nitrating mixture] B ->[(i) Sn/cone. HCI][(ii) NaOH] Aniline}\]
Write a short note on the following:
Ammonolysis
