Question

Salicylaldehyde can be prepared from phenol by:
A. Schotten-Baumann reaction
B. Kolbe’s reaction
C. Relmer-Tiemann reaction
D. Perkin reaction
E. Balz Schiemann reaction

Answer 1

Hint: Salicylaldehyde is an organic compound with chemical formula $C_7{H}_6{O}_2$. It is one of the three isomers of hydroxybenzaldehyde. Phenol and chloroform are heated together in the presence of sodium hydroxide and potassium hydroxide to form Salicylaldehyde.


Step by step answer: Salicylaldehyde is the organic compound with formula $C_7{H}_6{O}_2\left(C_6{H}_{4}CHO-2-OH\right)$. It is a colorless oily liquid which has a bitter almond odor at high concentrations. It is also known as 2-Hydroxybenzaldehyde. It is used in the production of coumarin, saligenin, in analytical chemistry etc.

The molecular formula of Phenol is $C_6{H}_{5}OH$. Phenol is an aromatic organic compound. It is a white crystalline volatile solid.

The molecular form of chloroform is $CHC{l}_3$. It is an artificial product and a colorless liquid with a non-irritating smell and slightly sweet taste.

Salicylaldehyde is prepared by heating phenol and chloroform together in the presence of potassium hydroxide and sodium hydroxide. This reaction is called the Relmer-Tiemann reaction.

$C_6{H}_{5}OH+CHC{l}_3\stackrel{3KOH}{\to }{C}_7{H}_6{O}_2$

The correct option is Option C, Reimer-Tiemann reaction.

Note: Phenol is a mild acid and can cause chemical burns, so it must be handled carefully. Salicylaldehyde is 2-Hydroxybenzaldehyde. 4- Hydroxybenzaldehyde is an organic compound with the same chemical formula as Salicylaldehyde but different structure, where hydroxyl group is present at the 4th carbon. Benzoic acid also has the same molecular formula as Salicylaldehyde, but with a carboxyl group. So be careful with the compounds when their IUPAC names are not given.