Question

Which is the correct method of synthesizing acetamide from acetone?
(a)- $C{{H}_{3}}COC{{H}_{3}}\xrightarrow{Pd/BaS{{O}_{4}}}C{{H}_{3}}CHO\xrightarrow{N{{H}_{3}}}C{{H}_{3}}C{{H}_{2}}N{{H}_{2}}\xrightarrow{{{H}_{2}}O}C{{H}_{3}}CON{{H}_{2}}$
(b)- $C{{H}_{3}}COC{{H}_{3}}\xrightarrow[NaOH]{{{I}_{2}}}C{{H}_{3}}COONa\xrightarrow[N{{H}_{3}}]{{{H}^{+}}}C{{H}_{3}}COON{{H}_{4}}\xrightarrow{\Delta }C{{H}_{3}}CON{{H}_{2}}$
(c)- $C{{H}_{3}}COC{{H}_{3}}\xrightarrow{Cr{{O}_{3}}}C{{H}_{3}}COOH\xrightarrow{N{{H}_{3}}}C{{H}_{3}}CON{{H}_{2}}$
(d)- $C{{H}_{3}}COC{{H}_{3}}\xrightarrow[NaOH]{{{I}_{2}}}C{{H}_{3}}COOH\xrightarrow{HCl}C{{H}_{3}}COCl\xrightarrow{N{{H}_{3}}}C{{H}_{3}}CON{{H}_{2}}$

Answer 1

Hint: Acetone is an organic compound in which there are three carbon atoms and there is a ketone group present. Pd and $BaS{{O}_{4}}$ are used to reduce aldehyde but they cannot react with ketones. The reaction of acid in the presence of acid is not possible.

Complete answer:
Acetone is an organic compound in which there are three carbon atoms and there is a ketone group present at the second carbon atom, its formula is $C{{H}_{3}}COC{{H}_{3}}$. Acetamide is an organic compound in which there are two carbon atoms and there is an amide functional group present, its formula is $C{{H}_{3}}CON{{H}_{2}}$.
Let us understand all the processes given in the options.
(a)- $C{{H}_{3}}COC{{H}_{3}}\xrightarrow{Pd/BaS{{O}_{4}}}C{{H}_{3}}CHO\xrightarrow{N{{H}_{3}}}C{{H}_{3}}C{{H}_{2}}N{{H}_{2}}\xrightarrow{{{H}_{2}}O}C{{H}_{3}}CON{{H}_{2}}$
In this procedure, the first step is the conversion of acetone to acetaldehyde by the reaction of palladium and barium sulfate. Barium sulfate and palladium are used to reduce aldehydes not ketones. So, this procedure is not possible.
(b)- $C{{H}_{3}}COC{{H}_{3}}\xrightarrow[NaOH]{{{I}_{2}}}C{{H}_{3}}COONa\xrightarrow[N{{H}_{3}}]{{{H}^{+}}}C{{H}_{3}}COON{{H}_{4}}\xrightarrow{\Delta }C{{H}_{3}}CON{{H}_{2}}$
In this procedure, acetone is reacted with iodine and sodium hydroxide and it forms sodium carboxylate, this on reaction with amine form the amine salt of carboxylate. This heating loses water molecules to form acetamide. Therefore, this process is correct.
(c)- $C{{H}_{3}}COC{{H}_{3}}\xrightarrow{Cr{{O}_{3}}}C{{H}_{3}}COOH\xrightarrow{N{{H}_{3}}}C{{H}_{3}}CON{{H}_{2}}$
In this procedure, acetone is oxidized to acetic acid by chromium trioxide, now this acetic on treatment with amine forms acetamide. In this process, the heating must be done. So, this procedure is also incorrect.
(d)- $C{{H}_{3}}COC{{H}_{3}}\xrightarrow[NaOH]{{{I}_{2}}}C{{H}_{3}}COOH\xrightarrow{HCl}C{{H}_{3}}COCl\xrightarrow{N{{H}_{3}}}C{{H}_{3}}CON{{H}_{2}}$
In this procedure, acetone is reacted with iodine and sodium hydroxide and it forms acetic acid which on reaction with HCl forms acetic chloride. This process is also incorrect because the reaction of an acid with acid is not possible.

Therefore, the correct answer is an option (b).

Note:
Pd and $BaS{{O}_{4}}$ are used to convert acid chlorides to aldehydes and hydrochloric acid, and this reaction is known as Rosenmund’s reaction. In carbonyl compounds, only aldehydes can be formed not ketones.