Question

Complete the following reaction:
${\text{C}}{{\text{H}}_{\text{3}}}{\text{C}}{{\text{H}}_{\text{2}}}{\text{Br }}\xrightarrow[\Delta ]{{aq{\text{ KOH}}}}A\xrightarrow[\Delta ]{{^{KMn{O_4}/{H^ + }}}}B\xrightarrow[\Delta ]{{N{H_3}}}C\xrightarrow[{alkali}]{{aq{\text{ }}KOH}}D$ and then find the value of D?
${\text{C}}{{\text{H}}_3}Br$
${\text{C}}{{\text{H}}_3}CON{H_2}$
${\text{C}}{{\text{H}}_3}N{H_2}$
${\text{CHB}}{{\text{r}}_3}$

Answer 1

Hint: First look at the reactions carefully, if this is directly giving you the product and if it is similar to the reaction you studied then answer accordingly. Like in the first part it is given that alkyl halide reaction with aqueous potassium hydroxide then alcohol is the product. And when alcohol reacts with potassium permanganate in an acidic medium then carboxylic acid is the product. When carboxylic acid reacts with amine then it forms amide and then finally if amide reacts with aqueous potassium hydroxide in basic medium then if forms amine.

Complete step by step answer:
First of all we would have to learn the reactions like if the reactants are given then what will be the products. In the given question the first reaction is given between the alkyl halide with aqueous potassium hydroxide then the product will be alcohol.
${\text{C}}{{\text{H}}_3}C{H_2}Br{\text{ }}\xrightarrow{{{\text{aq KOH}}}}{\text{ C}}{{\text{H}}_3}C{H_2}OH$Hence ethanol will be $A$
After that the reaction is in between A and potassium permanganate in acidic medium hence it will give carboxylic as the product.
${\text{C}}{{\text{H}}_3}C{H_2}OH{\text{ }}\xrightarrow[\Delta ]{{KMn{O_4}/{H^ + }}}C{H_3}COOH$. It will be B.
In the next reaction B reacts with amine then it will form amide as the product.
$C{H_3}COOH{\text{ }}\xrightarrow[\Delta ]{{N{H_3}}}{\text{ C}}{{\text{H}}_3}CON{H_2}$. It will be C.
And finally the last reaction is in between the C and aqueous potassium hydroxide in an alkaline medium then the product is methyl amine.
${\text{C}}{{\text{H}}_3}CON{H_2}{\text{ }}\xrightarrow[{alkali}]{{aq{\text{ KOH}}}}{\text{ C}}{{\text{H}}_3}N{H_2}$
Hence D will be methanamine.

So, the correct answer is Option C.

Note:
There are many named reactions. For example: wittig reaction, Grignard reaction( which is used to form alkanes), Cannizaro reaction, Aldol reaction(confirm the presence of ketone group in the compound),etc. If these types of reactions are there then write the product directly.