Метилизотиоциана химические свойства, назначение, производство
Описание
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.
Химические свойства
Methyl isothiocyanate is a crystalline solid.
Horseradish, acrid odor.
Вхождение
Reported found in horseradish.
Использование
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
Определение
ChEBI: An isothiocyanate having a methyl group attached to the nitrogen.
прикладной
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.
Реакции
A characteristic reaction is with amines to give methyl thioureas:
CH3NCS + R2NH → R2NC(S)NHCH3
Other nucleophiles add similarly.
Общее описание
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.
Реакции воздуха и воды
Highly flammable. Methyl isothiocyanate reacts with water to form carbon dioxide and methylamine gases.
Профиль реактивности
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.
Опасность
Toxic by ingestion, strong irritant to eyesand skin.
Угроза здоровью
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.
Пожароопасность
(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.
Безопасность
MITC is a dangerous lachrymator as well as being poisonous.
Возможный контакт
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.
Экологическая судьба
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).
Метаболический путь
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.
Перевозки
UN2477 Methyl isothiocyanate, Hazard class:
6.1; Labels: 6.1-Poison Inhalation Hazard, 3-Flammable
liquid, Inhalation Hazard Zone B.
Несовместимости
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
Утилизация отходов
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
Метилизотиоциана препаратная продукция и сырье
сырьё
препарат