Question

Carboxylic acids react with diazomethane to yield:
A. Amines
B. Alcohols
C. Esters
D. Amides

Answer 1

Hint: Diazomethane is a yellow, harmful, potentially flammable compound, which is a gas at room temperature. The chemical formula of diazomethane is\[{\rm{C}}{{\rm{H}}_{\rm{2}}}{{\rm{N}}_{\rm{2}}}\].

Complete Step by Step Solution:
Carboxylic acid is an organic acid that comprises a carboxyl group attached to an R-group or alkyl or aryl group.
The common formula of a carboxylic acid is\[{\rm{R - COOH}}\], where R implies the alkyl, alkenyl, aryl, or another group.
Carboxylic acids' examples comprise amino acids and fatty acids.
The IUPAC name of these compounds has the suffix -oic acid.
For example, ethanoic acid-\[{\rm{C}}{{\rm{H}}_3}{\rm{ - COOH}}\].
Deprotonation of a carboxylic acid provides a carboxylate anion of the formula \[{\rm{R - CO}}{{\rm{O}}^ - }\].
Diazomethane has the chemical formula \[{\rm{C}}{{\rm{H}}_{\rm{2}}}{{\rm{N}}_{\rm{2}}}\].
It has three resonance structures.
Its structure is as follows:



Image: Structure of diazomethane
Carboxylic acids react with diazomethane to yield methyl esters.
Diazomethane is highly reactive.
So, it is developed in situ and then instantly reacted with the carboxylic acid to yield the methyl ester.
The reaction occurs as follows:


Image: Reaction of the carboxylic acid with diazomethane.
This reaction occurs in two steps.
Step-1
The initial step of the mechanism is an easy acid-base reaction involving the deprotonation of carboxylic acid.
The carboxylate ions are formed in this step.
Step-2
The carboxylate ion then acts as the nucleophile in with protonated diazomethane to yield the methyl ester.
This occurs by substitution nucleophilic bimolecular reaction mechanism.
Nitrogen gas acts as a leaving group.
It is crucial to maintain reaction containers aired when gases are generated to prevent outbreaks.


Image: Mechanism of reaction of a carboxylic acid with diazomethane.
So, esters are produced as products in this reaction.

So, option C is correct.

Note: Diazomethane reacts with carboxylic acids to yield esters with the release of nitrogen gas. Amines, alcohols, and amides are not produced as products during the reaction of carboxylic acids with diazomethane.