10265-92-6 Usage
Chemical Properties
Different sources of media describe the Chemical Properties of 10265-92-6 differently. You can refer to the following data:
1. Methamidophos is a colourless crystalline solid with a pungent odour. It is readily soluble in water, alcohols, ketones, and aliphatic chlorinated hydrocarbons but sparingly soluble in ether and practically insoluble in petroleum ether. Methamidophos is also a breakdown product of another OP, namely, acephate. Methamidophos is slightly corrosive to mild steel and copper alloys.
2. Methamidophos is a colorless crystalline solid with a pungent odor. It is readily soluble in water, alcohols, ketones, and aliphatic chlorinated hydrocarbons, but sparingly soluble in ether and practically insoluble in petroleum ether. It is highly toxic, systemic with properties of an insecticide, acaricide, and avicide. The US EPA has grouped methamidophos as an RUP, meaning use and handling of this chemical substance requires qualifi ed, certifi ed, and trained workers. Methamidophos is effective against chewing and sucking insects and is used to control aphids, fl ea beetles, worms, white-fl ies, thrips, cabbage loopers, Colorado potato beetles, potato tube-worms, army-worms, mites, leafhoppers, and many others. Crop uses include broccoli, brussels sprouts, caulifl ower, grapes, celery, sugar beets, cotton, tobacco, and potatoes. It is used on many vegetables, hops, corn, peaches, and other crops. Methamidophos is also a breakdown product of another OP, namely, acephate. Methamidophos is slightly corrosive to mild steel and copper alloys.
3. Methamidophos is an off-white crystalline
solid.
Uses
Different sources of media describe the Uses of 10265-92-6 differently. You can refer to the following data:
1. Insecticide and acaricide.
2. Metamidophos is an organophosphate insecticide used in great quantities in rice fields in rice-producing countries.
3. Insecticide; acaricide.
4. Methamidophos is used to control a wide range of insects and
mites in a very large number of crops.
General Description
Crystalline solid, technical product is off-white with a pungent odor. Used as an insecticide on a number of vegetables and on cotton.
Reactivity Profile
Organophosphates, such as Methamidophos, are susceptible to formation of highly toxic and flammable phosphine gas in the presence of strong reducing agents such as hydrides. Partial oxidation by oxidizing agents may result in the release of toxic phosphorus oxides. Avoid strong acids or alkalis. [EPA, 1998].
Health Hazard
Different sources of media describe the Health Hazard of 10265-92-6 differently. You can refer to the following data:
1. Methamidophos is harmful or fatal if swallowed, inhaled, or absorbed through the skin.
2. Methamidophos is highly toxic to mammals. Inhalation of methamidophos causing weakness, tightness in the chest, wheezing, headache, blurred vision, pinpoint pupils, tearing,and runny nose are common early symptoms. On accidental ingestion and with severe poisoning, methamidiophos causes nausea, vomiting, diarrhea, and cramps, sweating and twitching, weakness, shakiness, blurred vision, pinpoint pupils, dyspnea (shortness of breath), tightness in the chest, sweating, confusion, changes in heart rate, convulsions, coma, respiratory failure, and death. People with health disorders, such as high blood pressure, problems of the gastrointestinal, heart, liver, lung, or nervous system, have been reported to be more sensitive to methamidophos-induced toxicity. Reports have indicated that occupational workers exposed to methamidophos who developed poisoning with symptoms such as pain (needle type) in the feet, legs, and hands, high blood pressure, gastrointestinal disorders, heart, liver, lung, or nervous system problems, may be more sensitive to methamidophos.
Fire Hazard
(Non-Specific -- Organophosphorus Pesticide, n.o.s.) Container may explode in heat of fire. Fire and runoff from fire control water may produce irritating or poisonous gases. (Non-Specific -- Phosphoramidothioic Acid, O-Ethyl S-Methyl Ester) Emits very toxic fumes of nitrogen oxides, phosphorus oxides, and sulfur oxides when heated to decomposition. Stable at neutral pH. Avoid strong acids or alkalis.
Agricultural Uses
Insecticide, Miticide: Methamidophos is a highly active, systemic, resid-ual organophosphate insecticide/acaricide/avicide with
contact and stomach action. Its mode of action in insects
and mammals is by decreasing the activity of an enzyme
important for nervous system function called acetylcholinesterase. This enzyme is essential in the normal transmission of nerve impulses. Methamidophos is a potent
acetylcholinesterase inhibitor. It is effective against chewing and sucking insects and is used to control aphids,
flea beetles, worms, whiteflies, thrips, cabbage loopers,
Colorado potato beetles, potato tubeworms, armyworms,
mites, leafhoppers, and many others. Crop uses include
broccoli, Brussels sprouts, cauliflower, grapes, celery,
sugar beets, cotton, tobacco, and potatoes. It is used abroad
for many vegetables, hops, corn, peaches, and other crops.
Generally, methamidophos is not considered phytotoxic
if used as directed, but defoliation has occurred when applied as foliar spray to deciduous fruit. It is compatible
with many other pesticides, but do not use with alkaline
materials. Methamidophos is slightly corrosive to mild
steel and copper alloys. This compound is highly toxic to
mammals, birds, and bees. Do not graze treated areas, and
be sure to wear protective clothing including respirator,
chemical goggles, rubber gloves, and impervious protective clothing. A U.S. EPA restricted Use Pesticide (RUP).
Not approved for use in EU countries
.
Trade name
ACEPHATE-MET?; BAY 71625?; BAYER
71628?; CHEVRON 9006?; CHEVRON ORTHO 9006?;
FILITOX?; GS-13005?; HAMIDOP?; METAFOS?;
MONITOR?; MTD?; NITOFOL?; NURATRON?;
ORTHO 9006?; PATROLE?; PILLARON?; SRA
5172?; SUPRACIDE?; SWIPE?; TAHMABON?;
TAMARON?; VITARON?
Safety Profile
Poison by ingestion,
inhalation, sh contact, subcutaneous, and
intraperitoneal routes. Human systemic
effects by ingestion: fasciculations, pupdlary
constriction, and sweating. A cholinesterase
inhbitor type of insecticide. When heated to
decomposition it emits very toxic fumes of
NOx, POx, and SOx. See also
PARATHION.
Potential Exposure
A potential danger to those involved
in the manufacture, formulation, and application of this
insecticide on vegetables and cotton
Environmental Fate
Chemical/Physical. Emits toxic fumes of phosphorus, nitrogen and sulfur oxides when
heated to decomposition (Sax and Lewis, 1987).
Metabolic pathway
Methamidophos is a contact insecticide which is particularly effective
against caterpillars and aphids. It also has some systemic action although
much less than acephate. There is some uncertainty concerning the nature
of the leaving group when the compound inhibits acetylcholinesterase
although most evidence suggests that it is methanethiolate. There are
claims that it requires metabolic activation to a more active inhibitor (Eto
et al., 1977) and yet other evidence that it does not (Khasawinah et al.,
1978). Most studies which have examined the biotransformation of
acephate have identified methamidophos as one of its metabolites and the
latter is considered to be the active metabolite. The main route of biotransformation
in soil is through deamination. In mammals, metabolism
involves de-O-methylation, de-S-methylation and deamination, with de-
O-methylation in the liver probably being the most important route.
There is no evidence as to whether demethylation is hydrolytic or oxidative.
Methamidophos and its metabolites are highly polar and no conjugates
have been identified. There is some evidence that the compound
can lead to delayed neurological degeneration in mammals through
inhibition of 'neuropathy target esterase'.
Metabolism
Acute oral LD50 for rats is about
20 mg/kg. Inhalation LC50 (4 h) for rats is 0.2 mg/L
air. NOEL (2 yr) for rats is 2 mg/kg diet (0.1 mg/kg/d).
ADI is 4 μg/kg b.w. Methamidophos itself shows only
a poor anti-AChE activity, oxidative activation being
suggested. It appears to cause delayed neuropathy.
The major part of administered methamidophos in
animals is rapidly eliminated from the body through
urine and respiration. The major metabolic routes are
O-demethylation, S-demethylation, and deamination. In
plants, deaminated methamidophos is a major metabolite.
Methamidophos is degraded rapidly in soil by deamination
and demethylation, to eventually form carbon dioxide and
phosphoric acid.
Degradation
Methamidophos is stable at pH 3-8 but it is hydrolysed in acids and
alkalis. Photodegradation is of minor importance (PM). The physicochemical,
electronic and molecular-orbital properties of methamidophos
have recently been described and the compound is apparently nonionised
at physiological pH (Singh et al., 1998).
The alkaline hydrolysis of methamidophos and its two N-methylated
derivatives was examined by Fahmy et al. (1972). In aqueous KOH the
main product was S-methyl phosphoramidothioate (2), whereas in less
polar media such as aqueous MeOH or acetone the route was via de-Smethylation
to give methyl phosphoramidate (3). It was concluded that
the two competing mechanisms for methamidophos hydrolysis were (i)
addition-elirnination on phosphorus leading to P-O bond cleavage, loss
of methoxide and formation of product 2, (ii) an elimination reaction
involving the amido proton to give P-S bond cleavage, loss of methanethiolate
and formation of product 3. Proposed routes for the
hydrolysis of methamidophos are shown in Scheme 1.
Incompatibilities
Incompatible with strong acids or alkali.
Attacks mild steel and copper-containing alloys (technical
grade)
Check Digit Verification of cas no
The CAS Registry Mumber 10265-92-6 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 1,0,2,6 and 5 respectively; the second part has 2 digits, 9 and 2 respectively.
Calculate Digit Verification of CAS Registry Number 10265-92:
(7*1)+(6*0)+(5*2)+(4*6)+(3*5)+(2*9)+(1*2)=76
76 % 10 = 6
So 10265-92-6 is a valid CAS Registry Number.
InChI:InChI=1/C2H8NO2PS/c1-5-6(3,4)7-2/h1-2H3,(H2,3,4)
10265-92-6Relevant articles and documents
Synthesis and characterization of O,S-dimethylphosphoramidothioate and N-acetyl O,S-dimethylphosphoramidothioate
Ghadimi,Mousavi,Rahnama,Rahimi
, p. 347 - 354 (2010)
O,S-Dimethylphosphoramidothioate (methamidophos) and N-acetyl O,S-dimethylphos- phoramidothioate (acephate) were synthesized by new methods to investigate the structure-activity study of acetyl cholinesterase (AChE) inhibition through the parameters of logP,δ 31P, and IC 50. After their characterization by NMR (31P, 31P{1H}, 13C, and 1H), IR, and mass spectroscopy, logP and δ31P (31P chemical shift in NMR) were used to evaluate lipophilicity and electronical properties. The logP values for methamidophos and acephate were experimentally determined by the GC-shake-flask method, and the ability of the compounds to inhibit human AChE was evaluated by a modified Ellman's assay. Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.
Synthetic method for improving yield of methamidophos intermediate
-
Paragraph 0019-0036, (2020/06/24)
The invention discloses a synthetic method for improving the yield of a methamidophos intermediate, and belongs to the technical field of fine chemical production. The method comprises the following steps: reacting O,O-dimethyl phosphoramidothioate with a catalyst and dimethyl sulfate at 25-60 DEG C to obtain methamidophos; wherein a solvent is halogenated alkane, and the catalyst comprises one ofmethyl iodide, methyl methanesulfonate, methyl trifluoromethanesulfonate, trimethylsilyl trifluoromethanesulfonate or isopropyl titanate. The method has the advantages that the process is simple, thereaction time is short, the obtained reaction yield is 90% or above, and the target product purity is high.
Mechanisms of composition change and toxic potentiation of chloramidophos emulsifiable concentrate during storage
Zhou, Shanshan,Zhang, Datong,Yang, Huayun,Zhang, Ying,Liu, Weiping
experimental part, p. 930 - 937 (2010/04/24)
Storage instability is one of the serious problems that greatly restrict pesticide use. Routine checks on the composition and toxicity of 30% emulsifiable concentrates (EC) of chloramidophos (CP) during storage indicated that 78.6% of the active ingredien