The Synthetic Routes of 5-Chloro-2(1H)-pyrimidinone

The Synthetic Routes of 5-Chloro-2(1H)-pyrimidinone: A Review of the Current Methods and Future Directions in the Chemical Industry

5-Chloro-2(1H)-pyrimidinone, also known as 5-chloro-2-pyrimidinone or simply 5-chloropyrimidinone, is an organic compound that has found widespread use in various applications in the chemical industry, including as a pharmaceutical intermediate, a catalyst, and a ligand.
The synthesis of 5-chloro-2(1H)-pyrimidinone can be accomplished through several different methods, each with its own advantages and disadvantages.
In this article, we will review the current synthetic routes for 5-chloro-2(1H)-pyrimidinone and discuss the future directions for this important compound in the chemical industry.

I.
Historical Background and early synthesis methods

5-Chloro-2(1H)-pyrimidinone was first synthesized in 1893 by the German chemist Emil Fischer, who used it as a starting material for the synthesis of the natural product aloin.
In the early 20th century, other synthetic routes for 5-chloro-2(1H)-pyrimidinone were developed, including the synthesis of the compound using chlorinated benzenes and chlorinated anilines.

II.
Current Synthetic Routes

There are several methods that are currently used to synthesize 5-chloro-2(1H)-pyrimidinone, including:

1. Electrophilic substitution reactions: One of the most common methods for synthesizing 5-chloro-2(1H)-pyrimidinone is through electrophilic substitution reactions, in which an electrophile is added to a molecule to form the desired compound.
   This method can be used to synthesize 5-chloro-2(1H)-pyrimidinone from chlorinated benzenes or chlorinated anilines.
   
2. Reduction of 5-chloro-2-nitro-pyrimidine: Another method for synthesizing 5-chloro-2(1H)-pyrimidinone is through the reduction of 5-chloro-2-nitro-pyrimidine, which can be synthesized from 2-nitro-pyrimidine and 5-chloro-2-oxazolidinone.
   
3. Direct synthesis from chlorite and malonic acid: A novel synthesis method for 5-chloro-2(1H)-pyrimidinone was reported in 2019, which involves the direct synthesis of the compound from chlorite and malonic acid in the presence of a catalyst.
   

III.
Advantages and Limitations of current synthetic methods

Each of the current synthetic methods for 5-chloro-2(1H)-pyrimidinone has its own advantages and limitations.
Electrophilic substitution reactions, for example, are relatively simple and can be used to synthesize the compound from inexpensive starting materials.
However, the reaction can be difficult to control, and the yield of the desired product can be low.
The reduction of 5-chloro-2-nitro-pyrimidine, on the other hand, has a higher yield but is more complex and requires more specialized equipment.

The novel synthesis method reported in 2019 has the advantage of being simple and efficient, and it does not require the use of hazardous reagents.
However, the method is currently limited to small-scale synthesis, and further research is needed to scale up the process for industrial applications.

IV.
Future Directions for 5-Chloro-2