Name: Basicity of Amine and Its Reactions
Uploaded: 2019-07-19
Duration: 6 min 28 s
Description: Amines are aliphatic and aromatic derivatives of ammonia and are considered weak bases. Let's learn about the basicity of amines and its roles.

Question

Write reaction to convert ethylamine into methylamine.

Accepted Answer

1) When ethylamine reacts with nitrous acid it gets converted to an ethyl diazonium salt. Diazonium salts are unstable. Therefore, ethyl diazonium salts get converted to ethyl alcohol thus liberating nitrogen gas and ethanol. Nitrous acid is prepared by acidifying the aqueous solution of sodium nitrate. Free nitrous acid is not stable and decomposes rapidly. This reaction is therefore done inside the reaction mixture which is known as in situ.
${CH}_{3} {CH}_{2} {NH}_{2} \overset{{NaNO}_{2} + HCl}{\to} [{CH}_{3} {CH}_{2} N^{+} {Cl}^{-}] [{CH}_{3} {CH}_{2} N^{+} {Cl}^{-}] \overset{H_{2} O}{\to} {CH}_{3} {CH}_{2} OH + N_{2} + HCl$
2) Now, ethanol can undergo oxidation on the addition of an oxidizing agent. Alcohol on oxidation first gets converted to Aldehyde which on further oxidation gives carboxylic acid.
So accordingly when ethanol reacts with an oxidizing agent it gives ethanoic acid.
${CH}_{2} {CH}_{2} OH \overset{[O]}{\to} {CH}_{3} CHO \overset{[O]}{\to} CH 3 COOH$

3) Ethanoic acid when heated in presence of ammonia then it gets converted to ethanamide. When an amide is treated with bromine in an aqueous solution of sodium hydroxide, then the amide undergoes a degradation reaction. The product thus formed will have one carbon atom less.
${CH}_{3} COOH \to_{Heat}^{{NH}_{3}, {SOCl}_{2}} {CH}_{3} {CONH}_{2} {CH}_{3} {CONH}_{2} \overset{NaOH / Br}{\to} {CH}_{3} {NH}_{2}$

The final reaction can be given as follows:
${CH}_{3} {CH}_{2} {NH}_{2} + {HNO}_{2} \to {CH}_{3} {CH}_{2} OH \overset{[O]}{\to} {CH}_{3} COOH \overset{{NH}_{3} / {SOCl}_{2}}{\to} {CH}_{3} {CONH}_{2} \overset{NaOH / {Br}_{2}}{\to} {CH}_{3} {NH}_{2}$

Write reaction to convert ethylamine into methylamine.

Important Questions on Amines

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