Used as a reagent in organic synthesis, particularly in Wittig reactions to convert aldehydes and ketones into alkenes. The pyridyl group enhances solubility in polar solvents and can assist in directing regioselectivity in certain transformations. Commonly employed in the preparation of conjugated systems and styrene derivatives, especially where nitrogen-containing aromatic structures are desired. Also utilized in the development of ionic liquids and as a precursor for phosphine ligands in catalysis. Its chloride salt form offers good stability and ease of handling in air-sensitive reactions.