Question

Give chemical equation for the following reactions: (i) Oxidation of propan-1-ol with alkaline KMnO\(_4\):

Hint:

In reactions involving phenols, electrophilic aromatic substitution usually leads to the formation of ortho and para products, while reactions with halides form aryl halides.

Answer 1

When propan-1-ol is oxidized with alkaline potassium permanganate (KMnO\(_4\)), it is oxidized to acetic acid (CH\(_3\)COOH): \[ \text{CH}_3\text{CH}_2\text{OH} + [O] \xrightarrow{\text{KMnO}_4} \text{CH}_3\text{COOH} \]
(ii) Reaction of phenol with chloroform in presence of aqueous NaOH: % Solution
Solution:
When phenol reacts with chloroform (CHCl\(_3\)) in the presence of aqueous NaOH, it forms phenol-formaldehyde (a part of the reaction is the formation of the phenoxide ion): \[ \text{C}_6\text{H}_5\text{OH} + \text{CHCl}_3 + \text{NaOH} \rightarrow \text{C}_6\text{H}_4\text{ClOH} + \text{NaCl} + \text{H}_2\text{O} \]
(iii) Reaction of phenol with dilute HNO\(_3\): % Solution
Solution:
Phenol reacts with dilute nitric acid to form a mixture of ortho- and para-nitrophenol: \[ \text{C}_6\text{H}_5\text{OH} + \text{HNO}_3 \rightarrow \text{C}_6\text{H}_4(\text{OH})\text{NO}_2 \, (\text{ortho and para isomers}) \]
(iv) Reaction of hydrogen iodide with methoxybenzene: % Solution
Solution:
Methoxybenzene (anisole) reacts with hydrogen iodide (HI) to form iodobenzene and methanol: \[ \text{C}_6\text{H}_5\text{OCH}_3 + \text{HI} \rightarrow \text{C}_6\text{H}_5\text{I} + \text{CH}_3\text{OH} \]
(v) Formation of propoxypropane from propan-1-ol: % Solution
Solution:
When propan-1-ol reacts with an alkyl halide (e.g., propyl chloride), it forms propoxypropane (an ether): \[ \text{CH}_3\text{CH}_2\text{OH} + \text{CH}_3\text{CH}_2\text{Cl} \rightarrow \text{CH}_3\text{CH}_2\text{OCH}_2\text{CH}_3 + \text{HCl} \]