Pyridine CAS:110-86-1

3.1 Solvent
Pyridine(110-86-1) is a polar, basic, low-reactive solvent, especially for dehydrochlorination reactions and extraction of antibiotics. In elimination reaction, pyridine acts as the base of the elimination reaction and bonds the resulting hydrogen halide to form a pyridinium salt. In esterifications and acylations, pyridine activates the carboxylic acid halides or anhydrides.

3.2 Medicines
Pyridine's chemical structure can be found in various medications that are synthesized thanks in part to pyridine. One example is a medication called esomeprazole, the generic name for Nexium. This is a medication that's used to treat GERD, or gastroesophageal reflux disease. Another example of a pyridine containing medication is loratadine, more commonly known by its brand name of Claritin. Loratadine helps in the treatment of allergies.

3.3 Pesticides
The main use of pyridine is as a precursor to the herbicides paraquat and diquat. The first synthesis step of insecticide chlorpyrifos consists of the chlorination of pyridine. Pyridine is also the starting compound for the preparation of pyrithione-based fungicides. Cetylpyridinium and laurylpyridinium, which can be produced from pyridine with a Zincke reaction, are used as antiseptic in oral and dental care products. Pyridine is easily attacked by alkylating agents to give N-alkylpyridinium salts. One example is cetylpyridinium chloride.

3.4 Synthesis of piperidine
Piperidine, a fundamental nitrogen heterocycle, is important synthetic building-block. Piperidines are produced by hydrogenation of pyridine with a nickel-, cobalt-, or ruthenium-based catalyst at elevated temperatures.
C5H5N + 3 H2 → C5H10NH3.5 Ligand and Lewis base
Pyridine is widely used as a ligand in coordination chemistry. As a ligand of metal complex, it can be easily replaced by a stronger Lewis base, which can be used in the catalysis of polymerization and hydrogenation reactions. After the completion of reaction, pyridine ligand replaced during the reaction can be restored again. Pyridine is also used as a base in condensation reactions. As a base, pyridine can be used as the Karl Fischer reagent, but it is usually replaced by alternatives with a more pleasant odor, such as imidazole.

3.6 Others
Except for above uses, Pyridine is also used to product polycarbonate resins, vitamins, food flavorings, paints, dyes, rubber products, adhesives, and waterproofing for fabrics. Pyridine is added to ethanol to make it unsuitable for drinking. It is also used in the in vitro synthesis of DNA.