The Synthetic Routes of 5-Bromo-2-chloro-7H-pyrrolo[2,3-d]pyrimidine

5-Bromo-2-chloro-7H-pyrrolo[2,3-d]pyrimidine is an important intermediate in the synthesis of various pharmaceuticals and agrochemicals.
The synthetic routes to this compound have been extensively studied and developed over the years, and there are several methods available for its synthesis.
In this article, we will discuss some of the synthetic routes to 5-bromo-2-chloro-7H-pyrrolo[2,3-d]pyrimidine.

One of the most common methods for the synthesis of 5-bromo-2-chloro-7H-pyrrolo[2,3-d]pyrimidine is through the reaction of 2-chloro-5-bromopyridine with 7-amino-2,3-dihydro-1H-pyrrolo[2,3-d]pyrimidine.
This reaction is carried out in the presence of a base, such as sodium hydroxide, and is followed by hydrolysis of the resulting N-Boc derivative to give the desired product.

Another method for the synthesis of 5-bromo-2-chloro-7H-pyrrolo[2,3-d]pyrimidine involves the reaction of 2,3-dihydro-1H-pyrrolo[2,3-d]pyrimidine-7-carboxylic acid with bromoform in the presence of pyridine.
This reaction is followed by treatment of the resulting 5-bromo-2-chloro-7H-pyrrolo[2,3-d]pyrimidine with a reducing agent, such as lithium aluminum hydride, to remove the carboxylic acid group.

A third method for the synthesis of 5-bromo-2-chloro-7H-pyrrolo[2,3-d]pyrimidine involves the reaction of 7-amino-2,3-dihydro-1H-pyrrolo[2,3-d]pyrimidine with 2-chloro-5-bromopyridine in the presence of aqueous hydrochloric acid.
This reaction is followed by treatment of the resulting N-Boc derivative with a base, such as sodium hydroxide, to hydrolyze the Boc group, and then with a reducing agent, such as lithium aluminum hydride, to remove the carboxylic acid group and the Boc group.

In addition to the above methods, there are several other synthetic routes to 5-bromo-2-chloro-7H-pyrrolo[2,3-d]pyrimidine, including those involving the use of microwave irradiation, hydrogenation, and other reducing agents.

The choice of synthetic route depends on various factors, including the availability of reagents, the cost of the synthesis, and the desired yield and purity of the product.
In addition, the synthetic route should be compatible with any subsequent modifications or transformations required in the synthesis of the final product.

Overall, 5-bromo-2-chloro-7H-pyrrolo[2,3-d]pyrimidine is an important intermediate in the synthesis of various pharmaceuticals and agrochemicals, and there are several synthetic routes available for its synthesis.
These routes involve the use of various reagents, conditions, and methods, and the choice of route depends on various factors, including the availability of reagents, the cost of the synthesis, and the desired yield and purity of the product.