イソチオシアン酸メチル

外観

白色/無色～うすい黄色粉末～塊～透明液体

溶解性

水8.2g/l(20℃)。エタノール、メタノール、アセトン、シクロヘキサノン、ジクロロメタン、クロロホルム、四塩化炭素、ベンゼン、キシレンに可溶。エタノール及びアセトンに極めて溶けやすく、水にほとんど溶けない。

用途

イソチオシアン酸メチル試験用標準品。

使用上の注意

不活性ガス封入

説明

Methyl iso thio cyanate is the organo sulfur compound with the formula CH₃N = C = S . This low melting colorless solid is a powerful lachrymator. As a precursor to a variety of valuable bioactive compounds, it is the most important organic iso thio cyanate in industry.

化学的特性

Methyl isothiocyanate is a crystalline solid. Horseradish, acrid odor.

天然物の起源

Reported found in horseradish.

使用

Usually used to study the effect of pesticide Metam (methyl isothiocyanate is its active ingredient) in the streamside microbial communities of the upper Sacramento river

定義

ChEBI: An isothiocyanate having a methyl group attached to the nitrogen.

主な応用

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

反応性

A characteristic reaction is with amines to give methyl thioureas:
CH₃NCS + R₂NH → R₂NC(S)NHCH₃
Other nucleophiles add similarly.

一般的な説明

A colorless liquid with a sharp odor. Lethal by inhalation of even small quantities of vapor. Does not have odor warning characteristics at low concentrations. Do not rely on the sense of smell to warn about the presence of vapors. Denser than water. Flash point below 20°F. May cause tearing and irritate the eyes, skin, nose and throat.

空気と水の反応

Highly flammable. Methyl isothiocyanate reacts with water to form carbon dioxide and methylamine gases.

反応プロフィール

Isocyanates and thioisocyanates, such as Methyl isothiocyanate, are incompatible with many classes of compounds, reacting exothermically to release toxic gases. Reactions with amines, aldehydes, alcohols, alkali metals, ketones, mercaptans, strong oxidizers, hydrides, phenols, and peroxides can cause vigorous releases of heat. Acids and bases initiate polymerization reactions in these materials. Some isocyanates react with water to form amines and liberate carbon dioxide. Polyurethanes are formed by the condensation reaction of diisocyanates with, for example, ethyl glycol.

危険性

Toxic by ingestion, strong irritant to eyesand skin.

健康ハザード

Very toxic; probable human oral lethal dose is 50-500 mg/kg, or between 1 teaspoonful and 1 oz. for a 70 kg (150 lb.) person. Highly irritating to skin, mucous membrances, and eyes. Human oral minimum lethal dose: approximately 1 g/kg.

火災危険

(Non-Specific -- Pesticide, Solid, n.o.s.) Methyl isothiocyanate may burn, but does not ignite readily. Fire may produce irritating or poisonous gases. When heated Methyl isothiocyanate emits very dangerous cyanides and sulfur compounds. Do not store below -4F or at elevated temperatures. Keep away from sparks.

安全性

MITC is a dangerous lachrymator as well as being poisonous.

職業ばく露

It is used as a soil fumigant. A mixture of methyl isothiocyanate and chlorinated C-3 hydrocarbons is used as a soil fumigant for control of weeds, fungi, insects, and nematodes.

環境運命予測

Soil. Though no products were reported, the reported half-life in soil is <14 days (Worthing and Hance, 1991).
Chemical/Physical. Emits toxic fumes of nitrogen and sulfur oxides when heated to decomposition (Sax and Lewis, 1987).

代謝経路

Methyl isothiocyanate is slowly decomposed in pure water, forming methylamine. It is metabolised in rats to the mercapturate via the glutathione conjugate which serves as a potential source of methyl isothiocyanate. Methyl isothiocyanate is reactive with cellular thiols and amines and its toxicity is associated with these reactions.

輸送方法

UN2477 Methyl isothiocyanate, Hazard class: 6.1; Labels: 6.1-Poison Inhalation Hazard, 3-Flammable liquid, Inhalation Hazard Zone B.

不和合性

Dust may form explosive mixture with air. Reacts with water, releasing carbon dioxide and methylamine gases. Unstable and reactive; sensitive to oxygen and to light. Incompatible with oxidizers (chlorates, nitrates, peroxides, permanganates, perchlorates, chlorine, bromine, fluorine, etc.); contact may cause fires or explosions. Keep away from alkaline materials, strong bases, strong acids, oxoacids, epoxides, alcohols, strong bases, amines, water, heat and cold. Attacks iron, zinc and other metals

廃棄物の処理

In accordance with 40CFR 165 recommendations for the disposal of pesticides and pesticide containers. Must be disposed properly by following package label directions or by contacting your local or federal environmental control agency, or by contacting your regional EPA office