Thioacetic Acid

Thioacetic acid (ethanethioic acid) is a colorless to pale yellow liquid with a strongly irritating odor — one of the important low-molecular-weight thiocarboxylic acids, widely used as a thioacylation reagent and sulfur source in organic synthesis. Soluble in water, ethanol and ether.

It undergoes free-radical addition to alkenes (thioesters), nucleophilic substitution with alkyl halides, formation of mixed thioanhydrides with acyl chlorides and thioamides with amines; it is also a common thiol-protecting reagent (via the acetylthio group) and participates in electrophilic sulfuration to introduce sulfur into target molecules.