Xylidine

Part of speech: noun

Definitions

1. A toxic aromatic amine derived from xylene, used in making dyes, pharmaceuticals and other organic chemicals
2. Any of several poisonous organic compounds of the amine family produced by replacing hydrogen in xylene with an amino group
3. A hazardous chemical base related to xylene, employed as an intermediate in the manufacture of dyes and drugs

Etymology: Xylidine was named in 1854 by the German chemist August Wilhelm von Hofmann, who made it while studying coal-tar derivatives in London. The name comes from "xylon," the Greek word for wood, because the compound was first obtained from wood tar, and the "-ine" ending marks it as an amine, a family of nitrogen-containing compounds. Chemists later found several isomers, differing only in how the methyl groups sit on the benzene ring, and that is why the name now covers a set of closely related substances rather than one single compound. The word was a coinage of the chemical laboratory, not an old term. Its root reaches back to the Greek "xylon," a plain word for timber that also gave English words such as "xylophone," which is a wooden instrument, and "xylem," the water-carrying tissue of plants. The dyes and industrial solvents made from xylidines were important in nineteenth- and twentieth-century manufacturing, and their toxicity is the reason they are now handled with care.