51235-04-2

Usage

Uses

Used in Forestry:
Hexazinone is used as a post bud contact killing herbicide and an inhibitor of photosynthesis in plants. It is particularly effective for tending young forests of evergreen coniferous forests, such as Pinus koraiensis, Pinus sylvestris, Picea spruce, and Pinus massoniana. It is applied before afforestation for weeding, extinguishing irrigation, maintaining and opening forest fire prevention, and improving forest soil.
Used in Infrastructure Maintenance:
Hexazinone is also utilized for weeding and irrigation on both sides of oil depots, airports, and roads, ensuring the safety and functionality of these critical infrastructures.
Used as a Herbicide:
Hexazinone is employed as a preemergence or postemergence herbicide to control many annual grasses and broad-leaved weeds in noncropped land and certain crops such as alfalfa, blueberries, coffee, pecans, and sugarcane. It can prevent and control a variety of weeds, including green bristlegrass, filipendula palmate, angelica dahurica, sedge, herba elsholtziae, reed, deyeuxia angustifolia, fern, clematis, veronica spuria, cephalanoplos segetum, wild oats, quinoa, millet, and more. Additionally, it can control woody plants like yellow lonicera japonica, pearl, hazel wood, spiraea salicifolia, acanthopanax senticosus, acanthopanax, winged elm, aspen, birch, quercus mongolica, linden, oak, linden, ashtree, phellodendron amurense rupr, and juglans mandshurica.
Dosage and Application:
A dose of 2～5kg/hm2 of Hexazinone can control weeds for a short term, while a dose of 6～12kg/hm2 is effective in preventing most perennial weeds. Nonionic surfactants can be added to the product to enhance its performance.

Chemical Properties

The pure product is white crystalline solid. m.p.115～117℃. Vapour pressure is 2.7×10-3Pa (25℃)、8.5×10-3Pa (86℃). Relative density is 1.25. The solubility at 25 ℃: 3880g/kg in chloroform, 2650g/kg in methanol, 836g/kg in dimethylformamide,790g/kg in acetone, 940g/kg in benzene, 386g/kg in toluene, 3g/kg in hexane and 33g/kg in water. In the water solution with pH value of 5~9, it is stable at normal temperature and will be decomposed by microbes in the soil.

Mechanism of action

It mainly inhibits the photosynthesis of plants and causes the disordered generation of plants and causes death. Both plant root and leaf surface can absorb the cyclohexanone, which is transported mainly through the xylem. It has great mobility in the soil and can be decomposed by soil microbes after entering the soil. It has no harm to the root of the pine tree. 7 days after the weeds have been treated, the leaves will have necrosis until the whole leaf has withered. The whole process including the upper part above ground (about 2 weeks) and the rotting of the root lasts for 1 month. It will last for 1 month from the appearance of necrosison the new leaves to rotting roots of the shrubs lasts for about 2 months. The first defoliation of non - objective arbor takes place 20~30 days after the injury. In the future, the new born leaves will be molted again, repeating 3~5 times in a row. From the spot to the formation of shrub leaf rot lasted for about 2 months. The upper part of the ground dies in 60~120 days. The roots rot in the fall of second.

Toxicity

The drug is of toxicity when acute oral LD50 is 1690mg/kg in rats, acute percutaneous is LD50>5278mg/kg in rabbits, acute transdermal is LD50>2000mg/kg in rats. It has a stimulating effect on the eyes of rabbits. The accumulative coefficient K value is >5, which belongs to the mild accumulative pesticide.There is no teratogenic, carcinogenic and mutagenic effects on animals within the range of experiments. No abnormality is found in the three generation reproduction test and neurotoxicity test. The non-cation dose for two years of feeding test: 200mg/kg for rats,LC50388mg/L for rainbow trout, LD50>5000mg/kg for quail, LD50>10000mg/kg for wild duck and, LC5060μg for per bee.

Production Methods

Hexazinone is a postemergence contact herbicide effective against many annual and biennial weeds and, except for Johnson grass, most perennial weeds. Human contact is likely at the use stage, and dermal contact and inhalation are of most concern.

Air & Water Reactions

Water soluble. Rapidly decomposed in solution by strong acids and bases.

Reactivity Profile

A triazine.

Carcinogenicity

No carcinogenicity was detected among pups of rats fed up to 5000 ppm for 2 years. Similarly, no increase in tumors was produced by feeding up to 10,000 ppm hexazinone to mice.

Environmental Fate

Soil/Plant. Biodegrades in soil and natural waters releasing carbon dioxide. The reported half-life in soil is 1 to 6 months (Hartley and Kidd, 1987). Rhodes (1980a) found that the persistence of hexazinone varied from 4 weeks in a Delaware sandy loam to 24 weeks in a Mississippi silt loam.Hexazinone is subject to microbial degradation (Rhodes, 1980a; Feng, 1987). Metabolites identified in soils, alfalfa and/or sugarcane include 3-(4-hydroxycyclohexyl)-6(dimethylamino)-1-methyl-1,3,5-triazine-2,4(1H,3H)-dione, 3-cyclohexyl-6-(methylamino)-1Feng (1987) monitored the persistence and degradation of hexazinone in a silt loam soil 104 days after treatment of the herbicide. After 104 days, 66% of the hexazinone degraded via hydroxylation to form the major metabolite 3-(4-hydroxycyclohexyl)-6(dimeNo traces of hexazinone or its metabolites were detected on treated blueberries (Jenson and Kimball, 1985).Photolytic. Photodegradation products identified in aqueous hexazinone solutions following exposure to UV light (λ = 300–400 nm) were 3-(4-hydroxycyclohexyl)-6-(dimethylamino)-1-methyl-1,3,5-triazine-2,4(1H,3H)-dione, 3-cyclohexyl-6-(methylamino)

Metabolic pathway

In clay and sand soils, hexazinone is metabolized by hydroxylation at the 4-position of the cyclohexane ring and mono-N-demethylation to give [3-(4- hydroxycyclohexyl)-6-(dimethylamino)-1-methyl-1,3,5- triazine-2,4-(1H,3H )-dione], and [3-cyclohexyl-6- (methylamino)-1-methyl-1,3,5-triazine-2,4-(1H,3H )- dione, respectively. N-Demethylated metabolite is found in a comparatively higher percentage than the hydroxylated metabolite in both clay and sand soils.

InChI:InChI=1/C12H20N4O2/c1-14(2)10-13-11(17)16(12(18)15(10)3)9-7-5-4-6-8-9/h9H,4-8H2,1-3H3

Upstream product

• 51162-60-8 3-cyclohexyl-1-methyl-6-methylsulfanyl-1H-[1,3,5]triazine-2,4-dione 
• 75-44-5 phosgene 
• 108-91-8 cyclohexylamine 
• 3173-53-3 Cyclohexyl isocyanate 

Relevant academic research and scientific papers

Novel method for synthesizing benzoxazinone (by machine translation)

The invention discloses a novel method for synthesizing benzoxazinone, and belongs to the technical field of synthesis. The method is: in the condition that toluene is taken as a solvent, and an acid binding agent is added, guanidine and auxiliary A are reacted to prepare a guanidyl ethyl ester; after water is removed by layering and distillation, cyclohexylamine is added with the substance such as guanidine, and is reacted, under the action of a catalyst, with ethyl guanidine formate to prepare the benzoxazinone. Compared with the existing synthetic method, the method has the advantages of high safety and strong operability, and compared with the existing synthetic method, the method has the advantages of high safety, and strong operability. Without rectification, the utility model has good application value. (by machine translation)

[...] a process for the preparation of herbicide

In order to solve the problems of side reaction and difficulty in inhibiting side reaction in the existing weedicide hexazinone preparation method, the invention discloses a new hexazinone preparation method which comprises the following steps: 1. reacting guanidine and cyclohexylamine so that the ester group on the guanidine is aminolyzed to generate an intermediate guanido urea; 2. reacting the intermediate guanido urea with phosgene under the action of an acid-binding agent so that the intermediate guanido urea is cyclized to generate hexazinone; and 3. cooling the mixture obtained in the step 2 to room temperature, carrying out vacuum filtration, washing, washing the mother solution with water, desolventizing under reduced pressure, adding petroleum ether to crystallize, filtering and drying to obtain the hexazinone crystal. The preparation method has the advantages of simple steps, no side reaction, high yield and low cost, and can obtain the high-purity hexazinone.

5,6-Dihydro-1,2,4,6-thiatriazin-5-one-1,1-dioxides

5,6-Dihydro-1,2,4,6-thiatriazin-5-one-1,1-dioxides of the formula STR1 where R1 is hydrogen, a metal atom or an unsubstituted or substituted ammonium radical, R2 is a saturated or unsaturated straight-chain aliphatic radical of up to 10 carbon atoms, a cycloaliphatic radical or 3 to 7 carbon atoms, a branched saturated or unsaturated aliphatic radical of 3 to 10 carbon atoms, a halogen-, alkoxy- or alkylmercapto-substituted aliphatic radical of 2 to 10 carbon atoms tetrahydrofuryl substituted methyl, a cycloalkoxy-substituted aliphatic radical of 4 to 10 carbon atoms, unsubstituted or halogen-substituted benzyl or phenyl, halophenyl, or alkylphenyl of a total of up to 10 carbon atoms, R3 is hydrogen, a straight-chain aliphatic radical of up to 10 carbon atoms, a cycloaliphatic radical of 3 to 7 carbon atoms, a branched aliphatic radical of 3 to 10 carbon atoms, haloalkyl, or alkoxyalkyl of 2 to 10 carbon atoms and X is oxygen and may also be sulfur if R2 is unsubstituted or halogen-substituted benzyl, processes for their preparation, and herbicides containing the above compounds.

Process for preparing herbicidal triazines

In a process for the preparation of 3-substituted-1-methyl-6-substituted-amino-s-triazine-2,4(1H,3H)-diones by liquid phase cyclization in the presence of an alkali metal alkoxide or hydroxide catalyst of an alkyl-N-(N-substituted carbamoyl-N',N-dialkylamidino)-N-methylcarbamate, by which by-product alkanol, ROH, is formed in the reaction dispersion, the improvement comprising removing the by-product alkanol from the reaction dispersion by vaporization therefrom substantially as it is formed.

Process for preparing herbicidal triazines

An improved process for preparing 3-cyclohexyl-1-methyl-6-dimethylamino-s-triazine-2,4(1H,3H)dione by the following reaction sequence: STR1 the improvement comprising using R=ethyl, n-propyl or isopropyl, preferably ethyl, thus permitting significantly higher practical overall yields. Related 3-substituted-1-methyl-6-substituted amino-s-triazine-2,4(1H,3H)diones and 4-thio-2,4(1H,3H)-diones are prepared similarly. These products are useful as herbicides.

Selective herbicide

1-Methyl-3-cyclohexyl-6-dimethylamino-s-triazine-2,4(1H,3H)-dione STR1 is useful for the selective control of many grassy weeds, and broadleaved weeds, in certain woody perennial crops, e.g., oil palm, rubber, coffee and tea plants.

Selective herbicide for pineapple crops

1-Methyl-3-cyclohexyl-6-dimethylamino-s-triazine-2,4(1H,3H)-dione STR1 is useful for the selective control of many broadleaved and grassy weeds in pineapple crops.

Selective herbicide for sugarcane

1-Methyl-3-cyclohexyl-6-dimethylamino-s-triazine-2,4(1H,3H)-dione. STR1 is useful for the selective control of many broadleaved and grassy weeds in sugarcane.

Selective herbicide for evergreen seedlings

1-Methyl-3-cyclohexyl-6-dimethylamino-s-triazine-2,4(1H,3H)-dione STR1 is useful for the selective control of many grassy weeds, broadleaved weeds, and weed trees in evergreen seedling stands.

Herbicidal triazines

Compounds of the formula: SPC1 Wherein X is oxygen or sulfur; R1 is alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, cycloalkylmethyl, cycloalkenylmethyl, bicycloalkyl, bicycloalkenyl, bicycloalkylmethyl, bicycloalkenylmethyl, phenyl, substituted alkyl, substituted cycloalkyl, or substituted phenyl; R2 is hydrogen or alkyl; R3 is H, methyl, or ethyl; and R4 is alkyl, alkenyl, alkynyl, or methoxy; and the salts with bases of those compounds wherein R2 is hydrogen, are useful as herbicides. A preferred compound is 1-methyl-3-cyclohexyl-6-dimethylamino-s-triazine-2,4(1H,3H)-dione.