The Synthetic Routes of 4-AMINO-3-CHLOROPYRIDAZINE

4-Amino-3-chloropyridazine is an important compound in the field of pharmaceuticals and agrochemicals.
It is used as an intermediate in the synthesis of various drugs and pesticides.
The synthesis of 4-amino-3-chloropyridazine can be achieved through several methods, including synthetic routes.
In this article, we will discuss some of the popular synthetic routes for the synthesis of 4-amino-3-chloropyridazine.

1. The classical route:
   The classical route for the synthesis of 4-amino-3-chloropyridazine involves the reaction of chloroacetamide with ammonia in the presence of a strong acid catalyst, such as sulfuric acid.
   The reaction results in the formation of N-chloroacetamide, which is then hydrolyzed to yield 4-amino-3-chloropyridazine.
   This route is simple and cost-effective but requires careful handling of the reagents and the catalyst.
   
2. The Hydrazoic Acid Route:
   The hydrazoic acid route involves the reaction of chloropyridazine-2-sulfenamide with hydrazoic acid in the presence of a catalyst, such as sodium hydroxide.
   The reaction results in the formation of 4-amino-3-chloropyridazine.
   This route is less commonly used than the classical route due to the toxicity and corrosiveness of hydrazoic acid.
   
3. The Glowacki-Hutchinson Route:
   The Glowacki-Hutchinson route involves the reaction of chloroacetanilide with sodium azide in the presence of a solvent, such as water or ether.
   The reaction results in the formation of 4-amino-3-chloropyridazine.
   This route is less commonly used due to the toxicity and instability of sodium azide.
   
4. The Leuckart-Wallach Route:
   The Leuckart-Wallach route involves the reaction of chloroacetanilide with sodium hydroxide in the presence of a solvent, such as water or ether.
   The reaction results in the formation of the sodium salt of chloroacetanilide, which is then treated with hydrazine to yield 4-amino-3-chloropyridazine.
   This route is also known as the Leuckart-Wallach modification of the Glowacki-Hutchinson route.
   
5. The Direct Nitration Route:
   The direct nitration route involves the reaction of chloroacetanilide with nitrating agents, such as nitric acid or nitrous acid, in the presence of a solvent, such as water or acetonitrile.
   The reaction results in the formation of 4-amino-3-chloropyridazine.
   This route is less commonly used due to the risk of explosion and the toxicity of the reagents.
   

In conclusion, 4-amino-3-chloropyridazine can be synthesized through various synthetic routes, each with its own advantages and disadvantages.
The choice of route depends on factors such as cost, safety, and selectivity.
The classical route is the most commonly used route, while the direct nitration route is the least commonly used due to the risks involved.