2636-26-2

Basic information

• Product Name: CYANOPHOS
• Synonyms: (o-p-cyanophenyl-o,o-dimethylphosphorothioate);4-(dimethoxyphosphinothioyloxy)benzonitrile;ai3-25675;BAY 34727;bay34727;BAYER 34727;bayer34727;caswellno268a
• CAS NO: 2636-26-2
• Molecular Formula: C₉H₁₀NO₃PS
• Molecular Weight: 243.22
• EINECS: 220-130-3
• Product Categories: INSECTICIDE
• Mol File: 2636-26-2.mol
• Article Data: 4

Chemical Properties

• Melting Point: 14-15°
• Boiling Point: bp0.09 119-120° (dec)
• Flash Point: >100 °C
• Appearance: /liquid
• Density: 1.3 g/cm³
• Vapor Pressure: 0.000282mmHg at 25°C
• Refractive Index: nD32.5 1.5404
• Storage Temp.: 0-6°C
• Water Solubility: 46 mg l-1 (30 °C)
• Merck: 13,2283
• BRN: 2695901
• CAS DataBase Reference: CYANOPHOS(CAS DataBase Reference)
• NIST Chemistry Reference: CYANOPHOS(2636-26-2)
• EPA Substance Registry System: CYANOPHOS(2636-26-2)

Safety Data

• Hazard Codes: Xn,N
• Statements: 21/22-50/53
• Safety Statements: 36/37-60-61
• RIDADR: 3018
• WGK Germany: 3
• RTECS: TF7600000
• HazardClass: 6.1(b)
• PackingGroup: III
• Hazardous Substances Data: 2636-26-2(Hazardous Substances Data)

Usage

Description

Cyanophos is an amber liquid, decomposes at 119–120 ?C, vp 105 mPa (20 ?C). Solubility in water is 46 mg/L (30 ?C). It is soluble in most organic solvents. Log Kow = 2.65. Cyanophos is effective in controlling a variety of insect pests including rice stem borers. Major formulation types are dustable powder, emulsifiable concentrate, wettable powder, and ultra low volume liquid.

Chemical Properties

Cyanophos is a yellow to reddish-yellow or amber liquid.

Uses

Different sources of media describe the Uses of 2636-26-2 differently. You can refer to the following data:
1. Cyanophos is a cholinesterase inhibitor used as an insecticide and avicide.
2. Insecticide.
3. Cyanophos is used to control a number of chewing and sucking pests in cotton, fruit and vegetables and public health pests.

General Description

Yellow to reddish-yellow transparent liquid. Used as an insecticide against rice stem borers and house flies. Not registered as a pesticide in the U.S.

Reactivity Profile

Organophosphates, such as CYANOPHOS, 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.

Health Hazard

Different sources of media describe the Health Hazard of 2636-26-2 differently. You can refer to the following data:
1. CYANOPHOS is an organophosphorus insecticide. It is a cholinesterase inhibitor. Death may occur after a massive oral dose; with smaller accidental doses, onset of illness may be delayed.
2. Exhibits acute, delayed, and chronic poisoning; highly toxic cholinesterase inhibitor;ingestion of small doses or skin absorption may produce delayed effects; massiveoral dose can be fatal; toxic symptomsinclude headache, dizziness, blurred vision,pinpoint pupils, vomiting, abdominal painand seizures; respiratory symptoms includeshortness of breath, respiratory depression,and respiratory paralysis.LD50 oral (rat): 18 mg/kg.

Fire Hazard

(Non-Specific -- Organophosphorus Pesticide, Liquid, n.o.s.) Container may explode in heat of fire. Fire and runoff from fire control water may produce irritating or poisonous gases. Unstable. Rapidly decomposes under alkaline conditions and upon exposure to light.

Potential Exposure

A potential danger to those involved in the manufacture, formulation, and application of this insecticide which is used against rice stem borers and house flies. It is not registered as a pesticide in the United States. Incompatibilities: Alkaline materials and exposure to light can cause rapid decomposition. Contact with oxidizers may cause the release of phosphorous oxides. Contact with strong reducing agents, such as hydrides, may cause the formation of flammable and toxic phosphine gas.

Metabolic pathway

The metabolism of cyanophos in plants and mammals is similar with deactivation via demethylation to desmethylcyanophos being important routes in both systems. Activation via oxidative desulfuration to cyanophos oxon, which is itself demethylated, also occurs in both plants and mammals. 4-Cyanophenol is an important metabolite which probably occurs principally by hydrolysis of the oxon in plants but in mammals is produced by oxidative dearylation of cyanophos also. In mammals it is conjugated as the sulfate ester as a major liver and urinary metabolite but conjugates of 4-cyanophenol have not been reported in plants.

Metabolism

The main biodegradation pathways in mammals are demethylation and aryl ester bond cleavage; the liberated cyanophenol is excreted in the form of the sulfate ester, formed by conjugation. The metabolism in plants is similar to that in mammals except the cyanophenol conjugation.

Shipping

UN3278 Organophosphorus compound, liquid, toxic, n.o.s., Hazard Class: 6.1; Labels: 6.1-Poisonous materials, Hazard Technical Name Required, Potential Inhalation Hazard (Special Provision 5). UN3018 Organophosphorus pesticides, liquid, toxic, Hazard Class: 6.1; Labels: 6.1-Poisonous materials.

Toxicity evaluation

It has a low mammalian toxicity: acute oral LD50 for rats is 710–730 mg/kg. Inhalation LC50 (4 h) for rats is >1500 mg/m3 air.

Degradation

The photodecomposition of [14C-cyano]cyanophos in acetone (a photosensitising solvent) irradiated by unfiltered UV light yielded cyanophos oxon (2), desmethylcyanophos oxon (3), 4-cyanophenol (4), 4-cyanobenzoic acid (5), 2-hydroxy-5-cyanobenzoic acid (6), CO2 and HCN. When cyanophos was exposed to sunlight in aqueous solution or as thin films on soil or silica gel TLC plates, which represent conditions more relevant to photolysis in the environment, only cyanophos oxon (2), desmethylcyanophos oxon (3) and 4-cyanophenol (4) were detected (Mikami et al., 1976) (Scheme 1).

Incompatibilities

A potential danger to those involved in the manufacture, formulation, and application of this insecticide which is used against rice stem borers and house flies. It is not registered as a pesticide in the United States. Incompatibilities: Alkaline materials and exposure to light can cause rapid decomposition. Contact with oxidizers may cause the release of phosphorous oxides. Contact with strong reducing agents, such as hydrides, may cause the formation of flammable and toxic phosphine gas.

Waste Disposal

In accordance with 40CFR165 recommendations for the disposal of pesticides and pesticide containers. Must be disposed properly by fol- lowing package label directions or by contacting your local or federal environmental control agency, or by contacting your regional EPA office.

InChI:InChI=1/C9H10NO3PS/c1-11-14(15,12-2)13-9-5-3-8(7-10)4-6-9/h3-6H,1-2H3

Upstream product

• 5633-96-5 potassium p-cyanophenoxide 
• 2524-03-0 dimethyl chlorothiophosphate 
• 122-14-5 MEP 
• 767-00-0 4-cyanophenol 
• 5930-72-3 dimethyl thiophosphite 

Downstream Products

• 632326-96-6 C₉H₁₁O₅PS 
• 61090-94-6 p-cyanophenyl dimethyl phosphate 
• 6431-54-5 O-(4-carbamoylphenyl) O,O-dimethyl thiophosphate 
• 767-00-0 4-cyanophenol 
• 23754-87-2 Natriumsalz des Thiophosphorsaeure-O,O-dimethylesters 

Relevant articles and documents

Mechanisms of abiotic degradation and soil-water interactions of pesticides and other hydrophobic organic compounds. Part 3. Nucleophilic displacement at the phosphorus centre of the pesticide fenitrothion [O,O-dimethyl O-(3-methyl-4-nitrophenyl) phosphorothioate] by oxygen nucleophil...

Rate constants for the reaction of the title compound, 1, with a number of oxygen nucleophiles, including structurally related phenoxides and oxygen-based α-nucleophiles, have been measured in aqueous solution at 25 deg C. A significant α-effect was observed, confirming participation of the nucleophile in the rate-limiting step of the reaction as well as indicating different transition states (TS) for the reaction of α-nucleophiles compared to normal ones. The Broensted-type correlation of log kNu vs. pKa of nucleophiles shows a linear plot for the series of structurally related phenoxides in the pKa range 5.4-10.0, straddling the pKa of the leaving group (3-methyl-4-nitrophenoxide, pKa 7.20), but is curved in the highly basic region corresponding to CF3CH2O- and HO- as nucleophiles. The slope of the linear portion of the plot (βNu) is 0.49 (R2 0.988). The linearity of the plot for the series of structurally related phenoxides is consistent with a concerted mechanism for nucleophilic attack at the P center of the substrate. A value of β1g -0.39 (R2 0.973) is measured for the reaction of PhO- with substituted phenyl dimethyl phosphorothioate esters. Combining the values of βNu and β1g gives βeq = 0.88; these parameters when considered together with the effective charge distribution in the TS, demonstrate that the TS for the symmetrical reaction (in which nucleophile = leaving group = 3-methyl-4-nitrophenoxide) has no significant phosphorylium ion character. The Leffler index points to a concerted reaction in which bond formation is slightly ahead of bound rupture in the TS. Data from the present study are compared with literature data for (thio)phosphoryl group transfer. We propose that, unless special structural and/or environmental features prevail, (thio)phosphoryl transfers between phenoxides are more likely to occur via a concerted mechanism. It is shown that the TS for the concerted transfer of (EtO)2P=O between two PhO- moieties shows more pentacoordiante intermediate character than the symmetrical reaction of 1 due to differences in (i) basicity of PhO- versus 3-CH3,4-NO2PhO-, and (ii) abilities of O and S in the P=X (X = O, S) moiety to stabilize the incoming negative charge.

Pesticide compositions and method

Toxicant, especially pesticide compositions, having lowered dermal toxicity are provided. The compositions include a lipophilic-pesticide, a nonionic surfactant and a dry inert diluent carrier. Methods for reducing the dermal toxicity of lipophilic toxicants, especially pesticides are provided, as well as methods for controlling insect pests using the disclosed compositions.