Dithiocarboxylic acids are

organosulfur compound Organosulfur compounds are organic compounds that contain sulfur. They are often associated with foul odors, but many of the sweetest compounds known are organosulfur derivatives, e.g., saccharin. Nature abounds with organosulfur compounds—sulfu ...

s with the formula . They are the dithia analogues of

carboxylic acid In organic chemistry, a carboxylic acid is an organic acid that contains a carboxyl group () attached to an R-group. The general formula of a carboxylic acid is or , with R referring to the alkyl, alkenyl, aryl, or other group. Carboxylic ...

s. A closely related and better studied family of compounds are the monothiocarboxylic acids, with the formula . Dithiocarboxylic acids are about 3x more acidic than the monothiocarboxylic acids. Thus, for dithiobenzoic acid pK_a = 1.92. Such compounds are commonly prepared by the reaction of

carbon disulfide Carbon disulfide (also spelled as carbon disulphide) is a neurotoxic, colorless, volatile liquid with the formula and structure . The compound is used frequently as a building block in organic chemistry as well as an industrial and chemical non ...

with a

Grignard reagent A Grignard reagent or Grignard compound is a chemical compound with the general formula , where X is a halogen and R is an organic group, normally an alkyl or aryl. Two typical examples are methylmagnesium chloride and phenylmagnesium bromide ...

: : : This reaction is comparable to the formation of carboxylic acids using a Grignard reagent and

carbon dioxide Carbon dioxide (chemical formula ) is a chemical compound made up of molecules that each have one carbon atom covalently double bonded to two oxygen atoms. It is found in the gas state at room temperature. In the air, carbon dioxide is transpar ...

. Dithiocarboxylate salts readily S-alkylate to give dithiocarboxylate esters: :{{chem2, RCS2Na + R'Cl -> RCS2R' + NaCl Aryldithiocarboxylic acids, e.g.,

dithiobenzoic acid Dithiobenzoic acid is the organosulfur compound with the formula C6H5CS2H. It is a dithiocarboxylic acid, an analogue of benzoic acid, but more acidic and deeply colored. Synthesis and reactions It can be prepared by sulfiding benzal chlorid ...

, chlorinate to give the

thioacyl chloride In organic chemistry, thioacyl chloride is a functional group of the type RC(S)Cl, where R is an organic substituent. Thioacyl chlorides are analogous to acid chlorides, but much rarer and less robust. The best studied is thiobenzoyl chloride, a ...

References

Organic acids Organosulfur compounds