Name | dimethoate |
Synonyms | ROGOR ROXION ROGOR(R) Rebelate ROXION(R) dimethoate ROXION(CELA)(R) 2-dimethoxyphosphinothioylthio-N-methylacetamide o,o-dimethyl methylcarbamoylmethyl phosphorodithioate O,O-dimethyl methylcarbamoylmethyl phosphorodithioate O,O-dimethyl S-methylcarbamoylmethyl phosphorodithioate O,O-DIMETHYL S-(N-METHYLCARBAMOYLMETHYL) PHOSPHORODITHIOATE O,O-dimethyl S-[2-(methylamino)-2-oxoethyl] phosphorodithioate |
CAS | 60-51-5 |
EINECS | 200-480-3 |
InChI | InChI=1/C5H12NO3PS2/c1-6-5(7)4-12-10(11,8-2)9-3/h4H2,1-3H3,(H,6,7) |
Molecular Formula | C5H12NO3PS2 |
Molar Mass | 229.26 |
Density | 1.281 |
Melting Point | 52-52.5°C |
Boling Point | 107°C (0.05 torr) |
Flash Point | 107°C |
Water Solubility | Slightly soluble. 2.5 g/100 mL |
Vapor Presure | 2.5 x 10-4 Pa (25 °C) |
Appearance | solid |
Merck | 13,3246 |
BRN | 1785339 |
pKa | 14.40±0.46(Predicted) |
Storage Condition | 2-8°C |
Refractive Index | nD65 1.5334 |
Physical and Chemical Properties | Density 1.281 melting point 52-52.5°C boiling point 107°C (0.05 torr) water-soluble clear solution. 2.5g/100 mL |
Use | It is a kind of disinfectant and acaricide, which can control a wide spectrum of pests and mites on a variety of crops, and is especially effective for health pests |
Risk Codes | R21/22 - Harmful in contact with skin and if swallowed. R63 - Possible risk of harm to the unborn child R43 - May cause sensitization by skin contact R36/37/38 - Irritating to eyes, respiratory system and skin. R23/24/25 - Toxic by inhalation, in contact with skin and if swallowed. R45 - May cause cancer R36 - Irritating to the eyes R20/21/22 - Harmful by inhalation, in contact with skin and if swallowed. R11 - Highly Flammable R67 - Vapors may cause drowsiness and dizziness R40 - Limited evidence of a carcinogenic effect |
Safety Description | S2 - Keep out of the reach of children. S36/37 - Wear suitable protective clothing and gloves. S24/25 - Avoid contact with skin and eyes. S23 - Do not breathe vapour. S53 - Avoid exposure - obtain special instructions before use. S26 - In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. S16 - Keep away from sources of ignition. |
UN IDs | UN 2783 |
WGK Germany | 3 |
RTECS | TE1750000 |
HS Code | 29309090 |
Hazard Class | 6.1(b) |
Packing Group | III |
Toxicity | LD50 orally in rats: 250 mg/kg (Schafer) |
NIST chemical information | Information provided by: webbook.nist.gov (external link) |
EPA chemical information | Information provided by: ofmpub.epa.gov (external link) |
toxicity | the acute oral LD50 of pure products to rats is 500~600 mg/kg, and that of industrial products is 320~380 mg/kg(94% ~ 96%). The acute percutaneous LD50 in male rats was 650mg/kg. The acute oral LD50 was 15mg/kg for male ducks and 40mg/kg (30mg/kg) for female ducks. Carp LC50 was 40mg/L(48h). The LD50 of bees is 0.09 μg/bee. |
use | systemic insecticide and acaricide, with contact killing and certain gastric toxicity, no fumigation effect. It can be used to prevent and control pricking mouthpart pests on a variety of crops, and is efficient against aphids, mites and latent leaf pests. It is used in rice, cotton, vegetables, fruit trees and other crops. For example, to control cotton aphid, cotton red spider and cotton bridge-building insect, spray 7.5~9kg of water with 40% emulsifiable concentrate of 7.5~10.5mL/100 m2, or spray 225~300g of 1.5% powder. It is used to control rice leafhopper, rice planthopper and rice thrips. 40% emulsifiable concentrate 7.5mL/100 m2 is used to spray 5.6~7.5kg of water. For leaf hoppers and planthoppers that produce antibodies, 50% rice blast net emulsifiable concentrate is increased by 5mL, which can improve the control effect. In addition, it can also be used to control aphids on vegetables, soybeans, rape, and astragalus crops, citrus fruit flies, scale insects, leaf-minding flies, vegetable ground cutworms, pear stink bugs, pear aphids, apple red spiders, mole crickets and other pests. It is better to use it above 20 ℃ with a residual effect of 5~7 days. It is a systemic contact killer and acaricide, which can control broad-spectrum pests and mites on a variety of crops, and is particularly effective against sanitary pests It is a contact killer and systemic insecticide, acaricide, mainly used to control pests of cotton, vegetables and other crops used to control aphids, red spiders, leaf jumping insects and other pests dimethoate is a high-efficiency broad-spectrum insecticide with contact and systemic acaricide. It has a higher toxic effect on a variety of pests, especially thorn and suction device pests, and has a wide range of insecticides. It can control aphids, red spiders, leaf miner flies, thrips, fruit flies, leaf bees, planthoppers, leafhoppers, and scale insects. Dimethoate can sneak into plants to maintain the efficacy for about a week. The oral LD50 of mice is 156.3 mg/kg, the percutaneous LD50 is 700-1150 mg/kg, and the intraperitoneal LD50 is 184 mg/kg. |
production method | industrial production methods of dimethoate mainly include chloroacetylmethylamine method and post-amine solution method. The latter method was developed after the chloroacetylmethylamine method. This method has few side reactions, the product purity can reach more than 90%, and the crude product yield is about 90%. the preparation of O,O-dimethyl dithiophosphoric acid (methyl thio for short) usually adopts the interaction of P2S5 and CH3OH, the methanol is appropriately excessive, the reaction temperature is 55~60 ℃, which is a strong exothermic reaction, and special attention should be paid to safety during operation. The reaction process is more complicated, and a series of side reactions occur at the same time. The yield and content of O,O-dimethyldithiophosphoric acid 75% ~ 80%. Using appropriate catalyst, the yield and content can reach about 90% at (55±2)℃. Preparation of O,O-methyl dithiophosphate O,O-dimethyl dithiophosphate reacts with sodium carbonate (ammonium) or sodium bicarbonate at room temperature to control the end-point pH to form a salt. Preparation of O,O-dimethyl-S-(methyl acetate) dithiophosphate O,O-dimethyl-S-(methyl acetate) dithiophosphate is prepared by the action of sodium O,O-dimethyl dithiophosphate and methyl chloroacetate. The raw material ratio is 1:1.7, and the reaction temperature is 55 ℃. If continuous production process is adopted, the preheating temperature is 60~70 ℃, and the reaction temperature is (80±5)℃. The synthesis of dimethoate O,O-dimethyl-S-(methyl acetate) dithiophosphate reacts with monomethylamine, the raw material ratio is 1:(1.2~1.3), the reaction temperature is -5~0 ℃. At the end of the reaction, benzene (or trichloroethylene) is added to extract dimethoate in the reaction solution, hydrochloric acid is added to adjust the pH value to 7, and an appropriate amount of water is added to promote stratification. |
category | pesticide |
toxicity classification | highly toxic |
acute toxicity | oral-rat LD50: 60 mg/kg; Oral-mouse LD50: 60 mg/kg |
flammability hazard characteristics | thermal decomposition of toxic phosphorus oxide, sulfur oxide, nitrogen oxide gas |
storage and transportation characteristics | warehouse ventilation and low temperature drying; separate from food raw materials storage and transportation |
fire extinguishing agent | sand, dry powder, foam |
toxic substance data | information provided by: pubchem.ncbi.nlm.nih.gov (external link) |