Thioacetic acid is an organosulfur compound with the molecular formula CH3C(O)SH.

[4] Thioacetic acid is prepared by the reaction of acetic anhydride with hydrogen sulfide:[5] It has also been produced by the action of phosphorus pentasulfide on glacial acetic acid, followed by distillation.

The compound exists exclusively as the thiol tautomer, consistent with the strength of the C=O double bond.

[8] Thioacetate esters undergo hydrolysis to give thiols.

A typical method for preparing a thiol from an alkyl halide using thioacetic acid proceeds in four discrete steps, some of which can be conducted sequentially in the same flask: In an application that illustrates the use of its radical behavior, thioacetic acid is used with AIBN in a free radical mediated nucleophilic addition to an exocyclic alkene forming a thioester:[9] Potassium thioacetate can be used convert nitroarenes to aryl acetamides in one step.