The Synthetic Routes of 4-HYDROXY-8-METHOXY-QUINOLINE-3-CARBOXYLIC ACID ETHYL ESTER

4-Hydroxy-8-methoxy-quinoline-3-carboxylic acid ethyl ester is an important compound in the field of organic synthesis and has a wide range of applications in the chemical industry.
This compound is commonly used as an intermediate in the synthesis of various pharmaceuticals, agrochemicals, and dyestuffs.
The synthetic routes for this compound can vary depending on the starting materials, the desired product, and the goals of the synthesis.

One of the common synthetic routes for 4-hydroxy-8-methoxy-quinoline-3-carboxylic acid ethyl ester is through the reaction of N-bromosuccinimide (NBS) with 8-methoxy-quinoline-3-carboxylic acid in the presence of a polar solvent such as water or DMSO.
This reaction results in the formation of the NBS derivative of the starting material, which can then be converted into the desired ethyl ester using basic conditions.

Another synthetic route for 4-hydroxy-8-methoxy-quinoline-3-carboxylic acid ethyl ester involves the reaction of 8-methoxy-quinoline-3-carboxylic acid with ethyl bromoisobutyrate in the presence of a catalyst such as zinc chloride.
This reaction results in the formation of the desired ethyl ester, which can then be converted into the target compound using hydrogenation or reduction conditions.

In addition to these synthetic routes, 4-hydroxy-8-methoxy-quinoline-3-carboxylic acid ethyl ester can also be synthesized through other methods such as the reaction of 8-methoxy-quinoline-3-carboxylic acid with ethyl chloride in the presence of a Lewis acid catalyst such as aluminum chloride, or the reaction of 8-methoxy-quinoline-3-carboxylic acid with ethyl iodide in the presence of a base such as sodium hydroxide.

The choice of synthetic route for 4-hydroxy-8-methoxy-quinoline-3-carboxylic acid ethyl ester will depend on various factors such as the availability and cost of the starting materials, the desired yield and purity of the target compound, and the compatibility of the reaction conditions with other synthetic steps in the overall synthesis.

In the chemical industry, 4-hydroxy-8-methoxy-quinoline-3-carboxylic acid ethyl ester is commonly used as an intermediate in the synthesis of various pharmaceuticals, agrochemicals, and dyestuffs.
For example, it can be used as an intermediate in the synthesis of anti-inflammatory drugs, antidepressants, and antibiotics.
It can also be used as a precursor for the synthesis of various dyes and pigments.

One example of a pharmaceutical synthesized using 4-hydroxy-8-methoxy-quinoline-3-carboxylic acid ethyl ester as an intermediate is celecoxib, a widely used nonsteroidal anti-inflammatory drug.
The synthesis of celecoxib involves the formation of a sulfonamide intermediate, which is then converted into the desired compound using a series of chemical reactions.
The sulfonamide intermediate is synthesized by reacting 4-hydroxy-8-methoxy-quinoline-3-carboxylic acid ethyl ester with isopropyl chloride and then treating the resulting isopropyl sulfonate with a suitable amine.

Another example of a pharmaceutical synthesized using 4-hydroxy-8-methox