The Production Process of 4-Chloro-6-phenyl-3(2H)-pyridazinone

The production process of 4-Chloro-6-phenyl-3(2H)-pyridazinone, commonly known as 4-CPP, is a complex chemical reaction that involves several steps and requires precise control over temperature, pressure, and reactant ratios.
The final product is a white crystalline solid that is commonly used in the production of pharmaceuticals, agrochemicals, and other specialty chemicals.

The production process of 4-CPP can be broken down into the following steps:

Step 1: Synthesis of 2-chloro-6-phenyl-4(3H)-quinazoline
The first step in the production of 4-CPP is the synthesis of 2-chloro-6-phenyl-4(3H)-quinazoline, also known as 2-CQ.
This is achieved by reacting 2-amino-6-phenyl-4(3H)-quinazoline with chlorine gas in the presence of a Lewis acid catalyst, such as AlCl3.
The reaction occurs in an inert solvent, such as ether or hexane, at a temperature of around 80-100°C.

Step 2: Reduction of 2-CQ to 2-CQH
The next step is to reduce the 2-CQ compound to its hydrazone derivative, 2-CQH.
This is achieved by treating 2-CQ with a reducing agent, such as LAH (lithium aluminum hydride), in an inert solvent, such as THF (tetrahydrofuran), at a temperature of around 70-80°C.
The reducing agent is added gradually to the reaction mixture while stirring.
The reaction is monitored by TLC (thin layer chromatography) to ensure complete reduction of the 2-CQ compound.

Step 3: Nitration of 2-CQH
The next step is to nitrate the 2-CQH compound to form 4-CPP.
This is done by treating 2-CQH with nitric acid in an inert solvent, such as DMF (dimethylformamide), at a temperature of around 120-140°C.
The reaction is exothermic and requires careful temperature control to prevent excessive heating and possible explosion.
The reaction is monitored by TLC to ensure complete conversion of the starting material.

Step 4: Deprotection of 4-CPP
The final step is to deprotect the 4-CPP compound to form the desired product.
This is achieved by treating 4-CPP with a strong solvent, such as ethanol or methanol, at a temperature of around 70-80°C.
The reaction is complete when the starting material has been completely consumed, as determined by TLC.

The overall yield of the production process depends on several factors, including the purity of the starting materials, the reaction conditions, and the efficiency of the downstream processing steps.
To ensure consistent quality and yield, it is important to maintain tight control over the reaction conditions and to conduct regular quality control checks throughout the production process.

In conclusion, the production process of 4-CPP involves several steps that require precise control over reaction conditions and the use of specialized reagents and equipment.
The final product is a valuable intermediate in the production of pharmaceuticals and other specialty chemicals, making it an important component in the chemical industry.