556-61-6 Usage
Description
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.
Chemical Properties
Different sources of media describe the Chemical Properties of 556-61-6 differently. You can refer to the following data:
1. colourless solid
2. Methyl isothiocyanate is a crystalline solid.
Horseradish, acrid odor.
3. Colorless to tan liquid; pungent, penetrating, mustard-like odor.
Occurrence
Reported found in horseradish.
Uses
Different sources of media describe the Uses of 556-61-6 differently. You can refer to the following data:
1. 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
2. Pesticide; soil fumigant.
3. Pesticide and soil fumigant used to control insects, soil fungi, nematodes.
Application
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.
Definition
ChEBI: An isothiocyanate having a methyl group attached to the nitrogen.
Reactions
A characteristic reaction is with amines to give methyl thioureas: CH3NCS + R2NH → R2NC(S)NHCH3 Other nucleophiles add similarly.
Aroma threshold values
Very high strength odor; recommend smelling in a 0.01% solution or less
General Description
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.
Air & Water Reactions
Highly flammable. Methyl isothiocyanate reacts with water to form carbon dioxide and methylamine gases.
Reactivity Profile
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.
Hazard
Toxic by ingestion, strong irritant to eyesand skin.
Health Hazard
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.
Fire Hazard
(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.
Flammability and Explosibility
Nonflammable
Safety
MITC is a dangerous lachrymator as well as being poisonous.
Synthesis
It is prepared industrially by two routes. Annual production in 1993 was estimated to be 4M kg. The main method involves the thermal rearrangement of methyl thio cyanate : CH3S - C ≡ N → CH3N = C = S It is also prepared via with the reaction of methylamine with carbon disulfide followed by oxidation of the resulting dithio carbamate with hydrogen peroxide. A related method is useful to prepare this compound in the laboratory. MITC forms naturally upon the enzymatic degradation of gluco capparin , a modified sugar found in capers.
Potential Exposure
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.
Environmental Fate
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).
Metabolic pathway
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.
Shipping
UN2477 Methyl isothiocyanate, Hazard class:
6.1; Labels: 6.1-Poison Inhalation Hazard, 3-Flammable
liquid, Inhalation Hazard Zone B.
Degradation
Methyl isothiocyanate is unstable and reactive. It is rapidly hydrolysed by
alkalis but more slowly in acidic or neutral solutions. DT50 values for
hydrolysis were 85,490 and 110 hours at pH 5,7 and 9, respectively. It is
sensitive to oxgen and to light (PM). The relatively slow hydrolysis of
methyl isothiocyanate in pure water can be accelerated by adding high
concentrations of acid. Thiocarbamic acid is formed that in turn
decomposes rapidly to protonated methylamine. Addition of water to the
isothiocyanate N=C bond via a mechanism involving synchronous nucleophilic
attack at carbon and proton transfer to nitrogen with a cyclic transition
state is proposed. Methyl isothiocyanate is 107 times less susceptible
to acid catalysis in water than its O-analogue (Joseph et al., 1992). It will
also combine with various essential nucleophilic centres in biological
systems. For example, it reacts with cysteine in vitro, forming a dithiocarbamate
derivative in solutions of pH greater than 6 (Goksoyr, 1964).
The fungicide is photolysed in the gas phase with a half life of 10 hours
under irradiation from a xenon arc lamp and slightly more than one day
for late summer sunlight in Nevada, USA. The relatively rapid photolysis
of methyl isothiocyanate had not previously been observed in other
experiments in aqueous solutions where rates were 20 times slower.
Products of photolysis were methyl isocyanide (2), sulfur dioxide, hydrogen
sulfide, N-methylformamide (3), methylamine and carbonyl sulfide.
Methyl isocyanide (2) was initially the main product and it yielded
methyl isocyanate (4) (Geddes et al., 1995).
Toxicity evaluation
MITC stimulates chemesthesis, the activation of receptors
associated with sensations of pain, touch, or thermal perception,
through activation of transient receptor potential (TRPA1)
ion channels. Isothiocyanate molecules have an electrophilic
carbon atom that reacts with nucleophilic components, such as
cysteine residues in the TRPA1 channels that are highly sensitive
and serve as a warning mechanism to prevent tissue
damage. MITC can form a reversible covalent bond with
receptors to stimulate a reaction instead of acting directly
through tissue damage. MITC is less potent than other isothiocyanates,
such as allyl isothiocyanate (i.e., the active
component of horseradish, wasabi, and mustard). At low
concentrations, endogenous nucleophiles (e.g., GSH) may
neutralize the electrophilic carbon and, therefore, prevent
damage, but as concentrations increase their effectiveness
decreases. Although the mode of action of MITC for systemic
toxicity is not known, MITC is proposed to react with, and
inactivate, the sulfhydryl group of essential enzymes in living
organisms.
Incompatibilities
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
Check Digit Verification of cas no
The CAS Registry Mumber 556-61-6 includes 6 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 3 digits, 5,5 and 6 respectively; the second part has 2 digits, 6 and 1 respectively.
Calculate Digit Verification of CAS Registry Number 556-61:
(5*5)+(4*5)+(3*6)+(2*6)+(1*1)=76
76 % 10 = 6
So 556-61-6 is a valid CAS Registry Number.
InChI:InChI=1/C2H3NS/c1-3-2-4/h1H3
556-61-6Relevant articles and documents
Molecular structure, vibrational spectra and photochemistry of 5-mercapto-1-methyltetrazole
Gomez-Zavaglia, A.,Reva, I. D.,Frija, L.,Cristiano, M. L.,Fausto, R.
, p. 182 - 192 (2006)
In this work, 5-mercapto-1-methyltetrazole was studied by low temperature matrix-isolation and solid-state infrared spectroscopy, DFT(B3LYP)/6-311++G(d,p) calculations and photochemical methods. In the low temperature neat solid phase and isolated in an argon matrix, the compound was found to exist in the 1-methyl-1,4-dihydro-5H-tetrazole-5-thione tautomeric form. The infrared spectra of the compound were fully assigned and correlated with structural properties. In situ UV-irradiation (λ > 235 nm) of the matrix-isolated monomer is shown to induce different photochemical processes, all of them involving cleavage of the tetrazole ring: e. g. (1) molecular nitrogen expulsion, with production of 1-methyl-1H-diazirene-3-thiol, which is produced in two different conformers; (2) ring cleavage leading to production of methyl isothiocyanate and azide; (3) simultaneous elimination of nitrogen and sulfur with production of N-methylcarbodiimide. Following these photoprocesses, subsequent reactions occur, leading to production of methyl diazene, carbon monosulphide and nitrogen hydride. Spectroscopic evidence of the production of the above-mentioned chemical species is provided.
Double three bromo 1,3-di-pyridine salt-based propane and its preparation method, method of use, recovery method and application
-
Paragraph 0075; 0076; 0185; 0186, (2016/10/07)
The invention discloses a double tribromo 1,3-bipyridine onium salt dimethylmethane, and a preparation method, an application method, a recovery method and application thereof. The preparation method comprises the following steps: dissolving 1,3-bipyridine onium salt dimethylmethane by using water, and then adding potassium bromide; adding potassium peroxymonosulfate sulfate compound brine solution to prepare a clear solution after dissolving potassium bromide, and then stirring and reacting at -10 to 0 DEG C until solid is separated out; separating out solid, so as to obtain the double tribromo 1,3-bipyridine onium salt dimethylmethane. The product can be used for preparing isothiocyanate, aromatic thiourea or acetanilide. The preparation method disclosed by the invention is mild in condition, and simple to operate the reaction process, and raw materials are easily available. The double tribromo 1,3-bipyridine onium salt dimethylmethane not only can be used as a brominating reagent, but also can be used as organic synthesis intermediates, meanwhile, the reaction efficiency is improved, and the double tribromo 1,3-bipyridine onium salt dimethylmethane is convenient to recover and can be recycled.
Synthesis and structure-activity relationships of aliphatic isothiocyanate analogs as antibiotic agents
Li, Deguang,Shu, Yanan,Li, Pingliang,Zhang, Wenbing,Ni, Hanwen,Cao, Yongsong
, p. 3119 - 3125 (2013/07/11)
Isothiocyanates (ITCs) are one of the many classes of breakdown products of glucosinolates found in plants and exhibit biologic activity against various pathogens. In this work, aliphatic isothiocyanates were prepared and the antimicrobial activities against plant pathogenic fungi and bacteria were tested to understand the structure-activity relationships. The results indicated that longer-chain derivatives exert a steric inhibition on toxicity of ITCs against Rhizoctonia solani because of steric hindrance and the order of the eight aliphatic ITCs was ethyl > n-propyl > methyl > n-hexyl > n-octyl > n-butyl > n-heptyl > n-pentyl. Because the hydrophobicity of ITCs was enhanced by increasing alkyl chain length, the antibacterial activity of ITCs against Erwinia carotovora was moderately intense with an increase in hydrophobicity and the order was n-octyl > n-pentyl > n-heptyl > n-hexyl > n-propyl > n-butyl > methyl > ethyl. The present study revealed that some of the compounds exhibited promising antimicrobial activity and could be used as an acceptable alternative to the traditional synthetic fungicides for controlling R. solani and E. carotovora.