Methyl isothiocyanate is the

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—sulf ...

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 ...

CH₃N=C=S. This low melting colorless solid is a powerful

lachrymator Tear gas, also known as a lachrymator agent or lachrymator (), sometimes colloquially known as "mace" after the early commercial aerosol, is a chemical weapon that stimulates the nerves of the lacrimal gland in the eye to produce tears. In ad ...

. As a precursor to a variety of valuable bioactive compounds, it is the most important organic

isothiocyanate In organic chemistry, isothiocyanate is the functional group , formed by substituting the oxygen in the isocyanate group with a sulfur. Many natural isothiocyanates from plants are produced by enzymatic conversion of metabolites called glu ...

in industry.

Synthesis

It is prepared industrially by two routes. Annual production in 1993 was estimated to be 4,000 tonnes. The main method involves the thermal rearrangement of methyl thiocyanate: :CH₃S−C≡N → CH₃N=C=S It is also prepared via with the reaction of

methylamine Methylamine is an organic compound with a formula of . This colorless gas is a derivative of ammonia, but with one hydrogen atom being replaced by a methyl group. It is the simplest primary amine. Methylamine is sold as a solution in methanol, ...

with

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 n ...

followed by oxidation of the resulting

dithiocarbamate In organic chemistry, a dithiocarbamate is a functional group with the general formula and structure . It is the analog of a carbamate in which both oxygen atoms are replaced by sulfur atoms (when only 1 oxygen is replaced the result is thioca ...

with

hydrogen peroxide Hydrogen peroxide is a chemical compound with the formula . In its pure form, it is a very pale blue liquid that is slightly more viscous than water. It is used as an oxidizer, bleaching agent, and antiseptic, usually as a dilute solution (3 ...

. A related method is useful to prepare this compound in the laboratory. MITC forms naturally upon the enzymatic degradation of glucocapparin, a

glucoside A glucoside is a glycoside that is derived from glucose. Glucosides are common in plants, but rare in animals. Glucose is produced when a glucoside is hydrolysed by purely chemical means, or decomposed by fermentation or enzymes. The name was ...

found in

caper ''Capparis spinosa'', the caper bush, also called Flinders rose, is a perennial plant that bears rounded, fleshy leaves and large white to pinkish-white flowers. The plant is best known for the edible flower buds (capers), used as a seasoning ...

Reactions

A characteristic reaction is with amines to give methyl

thiourea Thiourea () is an organosulfur compound with the formula and the structure . It is structurally similar to urea (), except that the oxygen atom is replaced by a sulfur atom (as implied by the ''thio-'' prefix); however, the properties of urea a ...

s: :CH₃NCS + R₂NH → R₂NC(S)NHCH₃ : Other nucleophiles add similarly.

Applications

Solutions of MITC are used in agriculture as soil fumigants, mainly for protection against fungi and nematodes. MITC is a building block for the synthesis of 1,3,4-thiadiazoles, which are

heterocyclic compound A heterocyclic compound or ring structure is a cyclic compound that has atoms of at least two different elements as members of its ring(s). Heterocyclic chemistry is the branch of organic chemistry dealing with the synthesis, properties, an ...

s used as herbicides. Commercial products include "Spike", "Ustilan," and "Erbotan." Well known pharmaceuticals prepared using MITC include Zantac and

Tagamet Cimetidine, sold under the brand name Tagamet among others, is a histamine H2 receptor antagonist that inhibits stomach acid production. It is mainly used in the treatment of heartburn and peptic ulcers. The development of longer-acting H2 re ...

Suritozole Suritozole (MDL 26,479) is an investigational cognition enhancer. It acts as a partial inverse agonist at the benzodiazepine receptor site on the GABAA ion channel complex, but does not have either anxiogenic or convulsant effects, unlike other B ...

is a third example. MITC is used in the Etasuline patent (Ex2), although the compound is question (Ex6) is with EITC.

Safety

MITC is a dangerous

as well as being poisonous.

References

{{Reflist Methyl esters Isothiocyanates Lachrymatory agents

Synthesis

Reactions

Applications

Safety

See also

References