The Production Process of 1,3,5-Tris(1-phenyl-1H-benzimidazol-2-yl)benzene

The Production Process of 1,3,5-Tris(1-phenyl-1H-benzimidazol-2-yl)benzene: A Comprehensive Overview

1,3,5-Tris(1-phenyl-1H-benzimidazol-2-yl)benzene, also known as phenylenebis(benzimidazole), is a white to off-white solid with a molecular formula of C22H14N4.
It is commonly used as a phosphor in electroluminescent (EL) devices and as a intermediate in the production of agricultural chemicals, pharmaceuticals, and other organic chemicals.
The production process of 1,3,5-Tris(1-phenyl-1H-benzimidazol-2-yl)benzene involves several steps, including synthesis, purification, and finishing.

Synthesis:
The synthesis of 1,3,5-Tris(1-phenyl-1H-benzimidazol-2-yl)benzene involves several chemical reactions, including condensation, substitution, and hydrogenation.
The synthesis process can be divided into several steps, including:

1. Preparation of the starting materials: The synthesis of 1,3,5-Tris(1-phenyl-1H-benzimidazol-2-yl)benzene requires several starting materials, including aniline, sodium hydroxide, and hydrochloric acid.
   These starting materials are prepared in advance according to specific chemical reactions.
   
2. Condensation reaction: The condensation reaction involves the reaction of aniline and sodium hydroxide to form a benzimidazole derivative.
   This reaction is typically carried out in the presence of a weak acid, such as hydrochloric acid, to remove the water that is generated during the reaction.
   
3. Substitution reaction: The substitution reaction involves the reaction of the benzimidazole derivative with a phenylboronic acid to form 1,3,5-Tris(1-phenyl-1H-benzimidazol-2-yl)benzene.
   This reaction is typically carried out in the presence of a transition metal catalyst, such as cobalt or palladium, to facilitate the reaction.
   
4. Hydrogenation: The hydrogenation reaction involves the reduction of the double bond in 1,3,5-Tris(1-phenyl-1H-benzimidazol-2-yl)benzene to form a fully saturated product.
   This reaction is typically carried out in the presence of a metal catalyst, such as palladium or platinum, and hydrogen gas.
   

Purification:
After the synthesis step, the product is typically purified to remove impurities and improve the overall quality of the product.
The purification process involves several steps, including:

1. Crystallization: The product is typically dissolved in a solvent, such as benzene or toluene, and allowed to crystallize.
   The crystals are then collected and dried to remove impurities.
   
2. Distillation: The purified product is then distilled to remove any remaining impurities and to increase the purity of the product.
   
3. Further purification: In some cases, further purification may be required to remove impurities that are difficult to remove using crystallization and distillation.
   This may involve using additional purification methods, such as chromatography or recrystallization.
   

Finishing:
The final step in the production process of 1,3,5-Tris(1-phenyl-1H-benzimidazol-2-yl)benzene is the finishing step, which involves the packaging and storage of the product.
The product is typically packaged in airtight containers to prevent exposure