The Synthetic Routes of 4-CHLORO-3(2H)-PYRIDAZINONE

The synthesis of 4-chloro-3(2H)-pyridazinone is an important chemical reaction in the pharmaceutical and agrochemical industries.
This compound is used as an intermediate in the synthesis of various medications and pesticides.
There are several synthetic routes to 4-chloro-3(2H)-pyridazinone, each with its own advantages and disadvantages.
In this article, we will discuss some of the most commonly used synthetic routes for the preparation of 4-chloro-3(2H)-pyridazinone.

One of the most widely used methods for the synthesis of 4-chloro-3(2H)-pyridazinone is the route involving the condensation of o-phenylendiamine with chloroacetone in the presence of a base such as sodium hydroxide.
This reaction involves the formation of a diazo compound, which undergoes a series of substitution reactions to produce the desired product.
The advantages of this route include its simplicity and the availability of the starting materials.
However, the disadvantage is that the reaction produces a lot of waste, including sodium chloride and water.

Another route to 4-chloro-3(2H)-pyridazinone involves the reduction of 4-chloro-3(2H)-pyridazinedione using hydrogen in the presence of a catalyst such as palladium on barium sulfate.
This route is advantageous because it does not produce any waste products, and the reaction can be easily monitored by TLC or GC.
However, the disadvantage is that the reaction requires the use of expensive reagents and equipment.

A third route to 4-chloro-3(2H)-pyridazinone involves the reaction of o-anisidine with chloroform in the presence of a Lewis acid catalyst such as aluminum chloride.
This reaction involves the formation of an aryl chloride, which is then coupled with another equivalent of o-anisidine to produce the desired product.
The advantages of this route include its simplicity and the low cost of the starting materials.
However, the disadvantage is that the reaction produces a lot of waste, including aluminum chloride and chloroform.

A fourth route to 4-chloro-3(2H)-pyridazinone involves the reaction of 2-chloro-4-nitroaniline with sodium hydroxide in the presence of a solvent such as dimethylformamide.
This reaction involves the reduction of the nitro group to an amine, which is then coupled with another equivalent of 2-chloro-4-nitroaniline to produce the desired product.
The advantages of this route include its simplicity and the availability of the starting materials.
However, the disadvantage is that the reaction produces a lot of waste, including sodium hydroxide and dimethylformamide.

In conclusion, there are several synthetic routes to 4-chloro-3(2H)-pyrd