Question

Cyclohexylamine when treated with nitrous acid yields (P) On treating (P) with $PCC$ results in (Q) When $(Q)$ is heated with dil. $NaOH$ we get $(R)$ The final product $(R)$ is :

• A.
• B.
• C.
• D.

Hint:

The reaction with PCC typically involves oxidation to a ketone, and heating with NaOH often leads to a condensation reaction.

Answer 1

The Correct Option is B

To solve this question, we need to follow the series of reactions step-by-step:

First, cyclohexylamine \((\text{C}_6\text{H}_{11}\text{NH}_2)\) is treated with nitrous acid \((HNO_2)\). This reaction leads to the formation of cyclohexanol \((\text{C}_6\text{H}_{11}\text{OH})\). This occurs because primary amines react with nitrous acid to form alcohols through the diazotization process followed by decomposition. The product of this step is designated as (P).

Next, we treat compound (P) with Pyridinium chlorochromate (PCC), an oxidizing agent. PCC typically oxidizes primary alcohols to aldehydes. Therefore, cyclohexanol will be oxidized to cyclohexanone. This compound is designated as (Q).

Finally, when cyclohexanone (Q) is treated with dilute sodium hydroxide \((\text{NaOH})\), an aldol reaction occurs. However, in this case, the product is dictated by the reaction conditions and the specific structure of (Q). Upon heating and dehydration, cyclohexanone undergoes an intramolecular reaction, yielding the final product (R). The product (R) turns out to be phenol.

Thus, the final product (R) is phenol, which corresponds to the image provided as option 2.

Hence, the correct answer is Option 2.