organic chemistry Organic chemistry is a subdiscipline within chemistry involving the science, scientific study of the structure, properties, and reactions of organic compounds and organic matter, organic materials, i.e., matter in its various forms that contain ...

, thiocarbamates (thiourethanes) are a family of

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 ...

s. As the prefix ''

thio- The prefix thio-, when applied to a chemical, such as an ion, means that an oxygen atom in the compound has been replaced by a sulfur atom. This term is often used in organic chemistry. For example, from the word ''ether,'' referring to an oxy ...

'' suggests, they are

sulfur Sulfur ( American spelling and the preferred IUPAC name) or sulphur ( Commonwealth spelling) is a chemical element; it has symbol S and atomic number 16. It is abundant, multivalent and nonmetallic. Under normal conditions, sulfur atoms ...

analogues of

carbamate In organic chemistry, a carbamate is a category of organic compounds with the general Chemical formula, formula and Chemical structure, structure , which are formally Derivative (chemistry), derived from carbamic acid (). The term includes orga ...

s. There are two isomeric forms of thiocarbamates: ''O''-thiocarbamates, (

ester In chemistry, an ester is a compound derived from an acid (either organic or inorganic) in which the hydrogen atom (H) of at least one acidic hydroxyl group () of that acid is replaced by an organyl group (R). These compounds contain a distin ...

s), and ''S''-thiocarbamates, (

thioester In organic chemistry, thioesters are organosulfur compounds with the molecular structure . They are analogous to carboxylate esters () with the sulfur in the thioester replacing oxygen in the carboxylate ester, as implied by the thio- prefix ...

s).

Synthesis

Thiocarbamates can be synthesised by the reaction of water or alcohols upon

thiocyanate Thiocyanates are salts containing the thiocyanate anion (also known as rhodanide or rhodanate). is the conjugate base of thiocyanic acid. Common salts include the colourless salts potassium thiocyanate and sodium thiocyanate. Mercury(II) t ...

s (

Riemschneider thiocarbamate synthesis The Riemschneider thiocarbamate synthesis converts alkyl or aryl thiocyanates to thiocarbamates under acidic conditions, followed by hydrolysis with ice water. The reaction was discovered by the German chemist in 1951 as a more efficient method to ...

): :RSCN + H₂O → RSC(=O)NH₂ :RSCN + R'OH → RSC(=O)NR'H Similar reactions are seen between alcohols and thiocarbamoyl chlorides such as dimethylthiocarbamoyl chloride; as well as between

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 ...

s and

cyanate The cyanate ion is an anion with the chemical formula . It is a resonance of three forms: (61%) ↔ (30%) ↔ (4%). Cyanate is the derived anion of isocyanic acid, H−N=C=O, and its lesser tautomer cyanic acid (a.k.a. cyanol), H−O−C� ...

s. The herbicide Cycloate is produced in this way: : Other related thiocarbamate herbicides include vernolate and triallate (. Salts of thiocarbamate arise by the reaction of amines with

carbonyl sulfide Carbonyl sulfide is the chemical compound with the linear formula . It is a colorless flammable gas with an unpleasant odor. It is a linear molecule consisting of a carbonyl double bonded to a sulfur atom. Carbonyl sulfide can be considered to ...

: :

Reactions

In the Newman-Kwart rearrangement ''O''-thiocarbamates can isomerise to ''S''-thiocarbamates. This reaction, which generally requires high temperatures, is an important method for the synthesis of thiophenols. Newman-Kwart-rearrangement-general

Occurrence

Goitrin Goitrin is an organosulfur compound classified as a derivative of oxazolidine and as a cyclic thiocarbamate. It reduces the production of thyroid hormones such as thyroxine. It is found in cruciferous vegetables such as cabbage, brussels sprouts ...

is a cyclic thiocarbamate found in some vegetables.

Uses

Thiocarbamate based herbicides (e.g. prosulfocarb) were introduced in 1957 and in 2017 was a $200,000,000 market. Other thiocarbamate herbicides are pebulate, molinate, EPTC, butylate, triallate, vernolate and cycloate.

References

{{Reflist Functional groups

Synthesis

Reactions

Occurrence

Uses

See also

References