The Synthetic Routes of 3-CHLORO-5-FORMYL-2-METHOXYPYRIDINE

3-Chloro-5-formyl-2-methoxypyridine is an important intermediate in the synthesis of various organic compounds and pharmaceuticals.
Its synthetic routes are wide and varied, and several methods have been developed to synthesize this compound.
In this article, we will discuss some of the most common synthetic routes for 3-chloro-5-formyl-2-methoxypyridine.

1. The classic route to 3-chloro-5-formyl-2-methoxypyridine involves the reaction of 2-nitro-4-chloro-5-methoxyacetophenone with sodium hydroxide in the presence of sodium chloride, followed by hydrolysis of the resulting N-nitroso compound with sodium hydroxide.
   
2. Another common route to 3-chloro-5-formyl-2-methoxypyridine involves the reaction of 2-chloropyridine-3,5-dione with methyl iodide in the presence of a base such as sodium hydroxide or potassium hydroxide, followed by hydrolysis of the resulting N-methylated compound with hydrochloric acid.
   
3. Another synthetic route to 3-chloro-5-formyl-2-methoxypyridine involves the reaction of 2-nitro-4-chloro-5-methoxyacetophenone with sodium hydroxide in the presence of sodium chloride, followed by reduction of the resulting N-nitroso compound with hydrogen in the presence of a catalyst such as palladium-on-charcoal.
   
4. 3-chloro-5-formyl-2-methoxypyridine can also be synthesized by the reaction of 2-chloropyridine-3,5-dione with 2-chloro-3-methoxyacrylic acid in the presence of a catalyst such as aluminum chloride.
   

In conclusion, 3-chloro-5-formyl-2-methoxypyridine is an important intermediate in organic synthesis, and several synthetic routes have been developed to synthesize this compound.
These routes include the reaction of 2-nitro-4-chloro-5-methoxyacetophenone with sodium hydroxide, the reaction of 2-chloropyridine-3,5-dione with methyl iodide, reduction of N-nitroso compounds, and the reaction of 2-chloropyridine-3,5-dione with 2-chloro-3-methoxyacrylic acid.
The choice of synthetic route will depend on the specific requirements of the synthesis and the availability of starting materials and reagents.