The Production Process of 7-Methyl-2-propyl-1H-benzimidazole-5-carboxylic acid

7-Methyl-2-propyl-1H-benzimidazole-5-carboxylic acid, commonly referred to as Carboxamide-2, is an important intermediate chemical used in the production of various pharmaceuticals, agrochemicals, and other specialty chemicals.
The production process of Carboxamide-2 involves several steps, including chemical reactions, purification, and isolation.
In this article, we will take a detailed look at the production process of Carboxamide-2 in the chemical industry.

Step 1: Preparation of 2-propyl-1H-benzimidazole-5-carboxylic acid

The production of Carboxamide-2 begins with the preparation of 2-propyl-1H-benzimidazole-5-carboxylic acid, which is the starting material for the subsequent chemical reactions.
To prepare this compound, 2-propyl-1H-benzimidazole-5-carboxylic acid chloride is first synthesized through a series of chemical reactions involving the reaction of 2-propyl-1H-benzimidazole with chloroformic acid.
The resulting 2-propyl-1H-benzimidazole-5-carboxylic acid chloride is then hydrolyzed using water to form the carboxylic acid.

Step 2: Nitration of 2-propyl-1H-benzimidazole-5-carboxylic acid

The next step in the production of Carboxamide-2 is the nitration of 2-propyl-1H-benzimidazole-5-carboxylic acid using nitric acid.
This reaction results in the formation of the 2-propyl-1H-benzimidazole-5-carboxylic acid mononitrate, which is an intermediate compound.

Step 3: Alkylation of 2-propyl-1H-benzimidazole-5-carboxylic acid mononitrate

The next step in the production of Carboxamide-2 is the alkylation of the 2-propyl-1H-benzimidazole-5-carboxylic acid mononitrate.
This is achieved by reacting the mononitrate with a primary alkyl halide, such as methyl iodide, in the presence of a Lewis acid catalyst, such as aluminum chloride.
This reaction results in the formation of the 2-propyl-1H-benzimidazole-5-carboxylic acid monoalkylate.

Step 4: Dealkylation and hydrolysis of 2-propyl-1H-benzimidazole-5-carboxylic acid monoalkylate

The next step in the production of Carboxamide-2 is the dealkylation and hydrolysis of the 2-propyl-1H-benzimidazole-5-carboxylic acid monoalkylate.
This is achieved by heating the monoalkylate with a strong acid, such as hydrochloric acid, in the presence of a solvent, such as ethyl acetate.
This results in the formation of the 2-propyl-1H-benzimidazole-5-carboxylic acid free base.

Step 5: Hydrolysis of 2-propyl-1H-benzimidazole-5-carboxylic acid free base

The final step in the production of Carboxamide-2 is the hydrolysis of the 2-propyl-1H-benzimidazole-5-carboxylic acid free base.
This is achieved by reacting the free base with water in the presence of a base, such as sodium hydroxide.
This results in the formation of the 2-propyl-1H-benzimidazole-5-carboxylic acid dihydrochloride, which is the final product of the production process.

Overall, the production process of Carboxamide-2 involves several chemical reactions and purification steps, including nitration, alkylation, dealkylation,