Benzene-1,2-dithiol is the

organosulfur compound Organosulfur chemistry is the study of the properties and synthesis of organosulfur compounds, which are organic compounds that contain sulfur. They are often associated with foul odors, but many of the sweetest compounds known are organosulfur der ...

with the

formula In science, a formula is a concise way of expressing information symbolically, as in a mathematical formula or a ''chemical formula''. The informal use of the term ''formula'' in science refers to the general construct of a relationship betwe ...

CH(SH). This colourless viscous liquid consists of a benzene ring with a pair of adjacent

thiol In organic chemistry, a thiol (; ), or thiol derivative, is any organosulfur compound of the form , where R represents an alkyl or other organic substituent. The functional group itself is referred to as either a thiol group or a sulfhydryl grou ...

groups. The

conjugate base A conjugate acid, within the Brønsted–Lowry acid–base theory, is a chemical compound formed when an acid gives a proton () to a base—in other words, it is a base with a hydrogen ion added to it, as it loses a hydrogen ion in the reve ...

of this diprotic compound serves as chelating agent in

coordination chemistry A coordination complex is a chemical compound consisting of a central atom or ion, which is usually metallic and is called the ''coordination centre'', and a surrounding array of chemical bond, bound molecules or ions, that are in turn known as ' ...

and a building block for the synthesis of other organosulfur compounds.Karlin, K. D.; Stiefel, E. I., Eds. “Progress in Inorganic Chemistry, Dithiolene Chemistry: Synthesis, Properties, and Applications” Wiley-Interscience: New York, 2003.

Synthesis

The compound is prepared by

ortho-lithiation Directed ortho metalation (DoM) is an adaptation of electrophilic aromatic substitution in which electrophiles attach themselves exclusively to the ortho- position of a direct metalation group or DMG through the intermediary of an aryllithium co ...

of benzenethiol using

butyl lithium Butyllithium may refer to one of 5 isomeric organolithium reagents of which 3 are commonly used in chemical synthesis: * ''n''-Butyllithium, abbreviated BuLi or nBuLi * ''sec''-Butyllithium, abbreviated ''sec''-BuLi or sBuLi, has 2 stereoisomers, ...

(BuLi) followed by sulfidation: :CHSH + 2 BuLi → CHSLi-2-Li + 2 BuH :CHSLi-2-Li + S → CH(SLi) :CH(SLi) + 2 HCl → CH(SH) + 2 LiCl The compound was first prepared from 2-aminobenzenethiol via

diazotization Diazonium compounds or diazonium salts are a group of organic compounds sharing a common functional group where R can be any organic group, such as an alkyl or an aryl, and X is an inorganic or organic anion, such as a halide. The parent, compou ...

. Alternatively, it forms from 1,2-dibromobenzene.

Reactions

Oxidation mainly affords the polymeric disulfide. Reaction with metal dihalides and metal oxides gives the dithiolate complexes of the formula LM(SCH) where LM represents a variety of metal centers, e.g. (CH)Ti.

Ketone In organic chemistry, a ketone is an organic compound with the structure , where R and R' can be a variety of carbon-containing substituents. Ketones contain a carbonyl group (a carbon-oxygen double bond C=O). The simplest ketone is acetone ( ...

s and

aldehyde In organic chemistry, an aldehyde () (lat. ''al''cohol ''dehyd''rogenatum, dehydrogenated alcohol) is an organic compound containing a functional group with the structure . The functional group itself (without the "R" side chain) can be referred ...

s condense to give the heterocycles called

dithiane A dithiane is a heterocyclic compound composed of a cyclohexane core structure wherein two methylene bridges ( units) are replaced by sulfur. The three isomeric parent heterocycles are 1,2-dithiane, 1,3-dithiane and 1,4-dithiane. They are all col ...

s: :CH(SH) + RR’CO → CH(S)CRR’ + HO

Related compounds

3,4-Toluenedithiol, also called dimercaptotoluene (CAS#496-74-2), behaves similarly to 1,2-benzenedithiol but is a solid at ambient temperatures (m.p. 135-137 °C). Alkene-1,2-dithiols are unstable, although metal complexes of alkene-1,2-dithiolates, called

dithiolene Dithiolene metal complexes are complexes containing 1,2-dithiolene ligands. 1,2-Dithiolene ligands, a particular case of 1,2-dichalcogenolene species along with 1,2-diselenolene derivatives, are unsaturated bidentate ligand wherein the two dono ...

complexes, are well known.

References

{{Reflist Thiols Benzene derivatives Foul-smelling chemicals