21087-64-9 Usage
Description
Metribuzin is a colorless crystalline solid that belongs to the class of 1,2,4-triazines. It is an aminotriazinone herbicide used in agriculture for both preand post-emergence in various crops. Metribuzin acts by inhibiting photosynthesis by disrupting photosystem II, making it effective for weed control.
Uses
Used in Agriculture:
Metribuzin is used as a selective herbicide for preemergence broad-leaved weed control in crops such as potatoes, tomatoes, lucerne, raspberry, and sugarcane. It is also used for postemergence weed control in beets and for selective control of annual grasses.
Used in Soybean, Potatoes, Tomatoes, and Sugar Cane:
Metribuzin is used as an herbicide in these crops to inhibit the photosynthesis of susceptible plant species, providing effective weed control.
Used in Asparagus, Peas, Lentils, and Cereals:
Metribuzin is used as a herbicide in these crops for the control of annual grasses and numerous broadleaf weeds, enhancing crop yield and quality.
Used in Fallow Lands:
Metribuzin is applied to fallow lands to control weed growth before planting new crops.
Available in Various Formulations:
Metribuzin is available in liquid suspension, water dispersible granular, and dry flowable formulations, making it suitable for different application methods and agricultural practices.
Reactivity Profile
A triazine derivative. Amines are chemical bases. They neutralize acids to form salts plus water. These acid-base reactions are exothermic. The amount of heat that is evolved per mole of amine in a neutralization is largely independent of the strength of the amine as a base. Amines may be incompatible with isocyanates, halogenated organics, peroxides, phenols (acidic), epoxides, anhydrides, and acid halides. Flammable gaseous hydrogen is generated by amines in combination with strong reducing agents, such as hydrides.
Hazard
Toxic material. Liver damage and hemato-logic effects. Questionable carcinogen.
Health Hazard
Low to moderate acute toxicity; single highdose may cause depression of central nervoussystem; repeated high doses affect thyroidand stimulate the metabolizing liver enzymes(ACGIH) 1986; excretes out rapidly; noirritant action on skin or eye; no teratogenic,mutagenic or carcinogenic effect observed inanimal studies.LD50 oral (rat): 1100 mg/kgLD50 oral (mouse): 698 mg/kgLD50 oral (guinea pig): 250 mg/kgLD50 skin (rat): 2000 mg/kg.
Trade name
AUTHORITY?; AXIOM? Metribuzin;
BAY 61597?; BAY DIC 1468?; BAYER 6159H?;
BAYER 6443H?; BAYER 94337?; BOUNDARY?;
CANOPY?; CONQUEST?; DIC 1468?; DOMAIN?;
LEXONE?; LEXONEEX?; PREVIEW?[C];
PYTHON?; SENCOR?; SENCORAL?; SENCOREX?;
SENCORER?; VAPCOR?
Safety Profile
Poison by ingestion and
intraperitoneal routes. Low toxicity by skin
contact. When heated to decomposition it
emits very toxic fumes of NOx and SOx.
Potential Exposure
A potential danger to those involved
in manufacture, formulation, and application of this
herbicide. A laboratory chemical. Used to make other
chemicals.
Environmental Fate
Soil. In soils, metribuzin undergoes deamination and further degradation forming water
soluble conjugates (Hartley and Kidd, 1987). Metribuzin degrades rapidly in soil (Kempson-
Jones and Hance, 1979; LaFleur, 1980). The half-lives in soil ranged from 4 to 9
weeks at 22°C and 60% moisture content to 9 to 11 weeks at 10°C and 10% moisture
content. The highest half-life reported ranged from 15 to 43 weeks in a soil having 60%
moisture content maintained at 10°C (Kempson-Jones and Hance, 1979).The dissipation rates (day–1) for metribuzin on Hillsdale silty loam, Cecil silty loam,
Regina heavy clay, Melfort clay loam and White City silt loam were 0.013-0.017, 0.055-
0.131, >0.017, >0.0016 and >0.023, respectively.Groundwater. According to the U.S. EPA (1986) metribuzin has a high potential to
leach to groundwater.Plant. Metribuzin is metabolized in soybean plants to a deaminated diketo derivative
which is nonphytoxic (Duke et al., 1991).
Photolytic. The simulated sunlight (l >230 nm) photolysis as a thin film on silica gel
or sand yielded 6-(1,1-dimethylethyl)-3-(methylthio)-1,2,4-triazin-5-(4H)-one and two
additional photoproducts. In both of the unnamed photoproducts, the methylthio group in
the parent compound is replaced by oxygen and one of the compounds also underwent
N-deamination (Bartl and Korte, 1975).
Chemical/Physical. Emits toxic fumes of nitrogen and sulfur oxides when heated to
decomposition (Lewis, 1990).
Shipping
UN2763 Triazine pesticides, solid, toxic, Hazard
Class: 6.1; Labels: 6.1-Poisonous materials.
Incompatibilities
Liquid is 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.
Waste Disposal
In accordance with 40CFR165,
follow 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. Use a licensed professional waste disposal service
to dispose of this material. Dissolve or mix the material with
a combustible solvent and burn in a chemical incinerator
equipped with an afterburner and scrubber. All federal, state,
and local environmental regulations must be observed.
Check Digit Verification of cas no
The CAS Registry Mumber 21087-64-9 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 2,1,0,8 and 7 respectively; the second part has 2 digits, 6 and 4 respectively.
Calculate Digit Verification of CAS Registry Number 21087-64:
(7*2)+(6*1)+(5*0)+(4*8)+(3*7)+(2*6)+(1*4)=89
89 % 10 = 9
So 21087-64-9 is a valid CAS Registry Number.
InChI:InChI=1/C8H14N4OS/c1-8(2,3)5-6(13)12(9)7(14-4)11-10-5/h9H2,1-4H3
21087-64-9Relevant articles and documents
Preparation method of metribuzin
-
Paragraph 0041-0044, (2019/04/04)
The invention discloses a preparation method of metribuzin. The preparation method is characterized in that methanol-water is used as a solvent; under the conditions that a pH value is 11.5-12.5, andlithium ions exist, triazinone reacts with halomethane at a temperature of 5-20 DEG C till the triazinone completely disappears. The preparation method disclosed by the invention has the beneficial effects that when the metribuzin is prepared, the lithium ions are added in a reaction system, so that the selectivity to the generation of the metribuzin by reaction is improved; by the addition of thelithium ions, the ability of the triazinone to exist in the form of mercaptan is improved, so that the concentration and the reactivity of sulfur anions in the reaction system are increased; a generated product mainly is an S-methylation product, so that the production possibility of an N-methylation product is reduced, therefore, no impurity is basically generated in the product, and the purityof the metribuzin is above 99 percent.
Synthesis method of metribuzin
-
Paragraph 0036-0045, (2019/01/24)
The invention relates to a synthesis method of metribuzin. The metribuzin is prepared from methylmercapto-carbazide and 3,3-dimethyl ketobutyric acid through reaction under the effect of catalysts, wherein the structure formula of methylmercapto-carbazide is shown in description. Compared with the prior art, the synthesis method has the advantages that the cyclization reaction conditions are mild;the reaction time is short; the yield is high; the product quality is high; the discharging quantity of three wastes (waste water, waste gas and waste solid) is reduced; the yield and the economic benefits are improved.
Synthetic method of 4-amino-6-tert-butyl-3-methylthio-1,2,4-triazine-5(4H)-ketone
-
Paragraph 0029-0032; 0034-0039, (2017/09/13)
The invention discloses a synthetic method of 4-amino-6-tert-butyl-3-methylthio-1,2,4-triazine-5(4H)-ketone. The synthetic method comprises the following steps: sequentially adding process water, caustic soda flakes, triazone and a catalyst into a dissolving kettle till complete dissolution under stirring conditions; transferring a material into a synthetic kettle, introducing methyl bromide into the synthetic kettle under stirring conditions, preparing to obtain metribuzin and performing heat preservation for 0.5-1 hour after the end of reaction; introducing nitrogen gas into a reaction kettle to blow out redundant methyl bromide, meanwhile raising the temperature in the synthetic kettle to 48-55 DEG C and performing heat preservation for 0.5-1.5 hours; cooling, washing and filtering the material to obtain metribuzin. The synthetic method disclosed by the invention has the benefits that the adding quantity of the catalyst is small, and no toxic or side effect exists; on one hand, the raw material input cost and the post-processing process cost of a recycled product solvent are reduced; on the other hand, the consumption of the catalyst is less, and compared with methanol, the risk of easy explosion is avoided, so that the safety coefficients in the production process are improved.
