4-Chloro-thieno[3,2-c]pyridine-2-carboxylic Acid Methyl Ester is a synthetic building block that is made from 2,4-Dichloropyridine (D435830), which is a versatile reactant used in the preparation of host materials for light-emitting diodes with heterocyclic cores. 2,4-Dichloropyridine is used in the preparation of sulfonylated pyridines, pyrazine and quinoline via aromatic nucleophilic substitution of azines with sodium sulfinates.