41394-05-2

Basic information

• Product Name: Metamitron
• Synonyms: 3-methyl-4-amino-6-phenyl-1,2,4-triazin(4h)-on;3-Methyl-4-amino-6-phenyl-1,2,4-triazin(4H)-one;4-Amino-3-methyl-6-phenyl-1,2,4-triazin-5(4H)-one;4-amino-3-methyl-6-phenyl-as-triazin-5(4h)-on;as-Triazin-5(4H)-one, 4-amino-3-methyl-6-phenyl-;Bay-drw 1139;bay-drw1139;Countdown
• CAS NO: 41394-05-2
• Molecular Formula: C₁₀H₁₀N₄O
• Molecular Weight: 202.21
• EINECS: 255-349-3
• Product Categories: Heterocyclic Compounds;HERBICIDE;Building Blocks;Heterocyclic Building Blocks;Triazines;farm chemicals;pharmaceutical intermediate Metamitron
• Mol File: 41394-05-2.mol
• Article Data: 9

Chemical Properties

• Melting Point: 167-170 °C(lit.)
• Boiling Point: 340.33°C (rough estimate)
• Flash Point: 11 °C
• Appearance: /
• Density: 1.2165 (rough estimate)
• Vapor Pressure: 0.000117mmHg at 25°C
• Refractive Index: 1.6300 (estimate)
• Storage Temp.: APPROX 4°C
• PKA: 1.54±0.20(Predicted)
• Water Solubility: 1.8g/L(20 oC)
• Merck: 14,5924
• BRN: 613129
• CAS DataBase Reference: Metamitron(CAS DataBase Reference)
• NIST Chemistry Reference: Metamitron(41394-05-2)
• EPA Substance Registry System: Metamitron(41394-05-2)

Safety Data

• Hazard Codes: Xn,N,T,F
• Statements: 22-50-39/23/24/25-23/24/25-11
• Safety Statements: 61-45-36/37
• RIDADR: UN 3077 9/PG 3
• WGK Germany: 2
• RTECS: XZ3015000
• HazardClass: 9
• PackingGroup: III
• Hazardous Substances Data: 41394-05-2(Hazardous Substances Data)

Usage

Uses

Herbicide.

Definition

ChEBI: A member of the class of 1,2,4-triazines that is 1,2,4-triazin-5(4H)-one substituted by an amino group at position 4, a methyl group at position 3 and a phenyl group at position 6.

General Description

4-Amino-3-methyl-6-phenyl-1,2,4-triazin-5-one, commonly known as metamitron, is a pesticide having low polarity and is hydrophobic in nature. Its pKa value is 2.9.

Agricultural Uses

Herbicide: Metamitron is a selective systemic herbicide that is absorbed through roots and leaves and inhibits photosynthesis. It is used to control grasses and broadleaf weeds in sugar beets and fodder beets. Not currently registered in the U.S. Used in most European countries and having 34 global suppliers .

Trade name

BAY 6676?; BAY-DRW 1139?; DRW 1139?; GALAHAD?; GOLDBEET?; GOLTIX?; GOLTIX? 90; GOLTIX? SUPER; GOLTIX? WG; MM 70?; HERBRAK?; MARQUISE?; SKATER?; TORERO? (metamitron + ethofumesate)

Metabolic pathway

Degradation of metamitron by photolysis is strongly dependent on solvents and oxygen, and no photoreaction is found in methanol, acetonitrile, and hexane, nor in oxygen-free water. In water solution, photolytic degradation occurs and results in the formation of desaminometamitron and a ring-opening polar benzoylacetyl hydrazine (tentatively assigned).

InChI:InChI=1/C10H10N4O/c1-7-12-13-9(10(15)14(7)11)8-5-3-2-4-6-8/h2-6H,11H2,1H3

Synthetic route

phenylglyoxylic acid ethyl ester (1603-79-8) + acetic acid hydrazide (1068-57-1) → metamitron (41394-05-2)

Conditions	Yield
Stage #1: phenylglyoxylic acid ethyl ester; acetic acid hydrazide In ethanol at 25℃; for 1h; Stage #2: With ethylenediaminetetraacetic acid In ethanol at 25℃; for 3.33333h; Temperature; Concentration; Further stages;	92%

methyl 2-oxo-2-phenylacetate (15206-55-0) + Acetohydrazid-hydrazon-hydrochlorid (56873-72-4) → metamitron (41394-05-2)

Conditions	Yield
With triethylamine 1.) CH3OH, 2 h, reflux, 2.) 16 h, room temperature; 1 h, reflux; Yield given. Multistep reaction;

acethydrazidine hydrochloride + N-acetyl-2-oxo-2-phenylacetamide (79848-81-0) → metamitron (41394-05-2)

Conditions	Yield
With pyridine In methanol; water
In water

Benzoylformic acid (611-73-4) → metamitron (41394-05-2)

Conditions	Yield
Multi-step reaction with 4 steps 1: hydrogenchloride / 4 h / 45 - 60 °C 2: sulfuric acid / methanol / 8 h / 20 - 65 °C 3: hydrazine hydrate / 20 - 25 °C 4: butan-1-ol / 8 h / 20 - 132 °C / Reflux View Scheme

C10H12N4O2 (56735-29-6) → metamitron (41394-05-2)

Conditions	Yield
In butan-1-ol at 20 - 132℃; for 8h; Reflux;

benzoyl cyanide (613-90-1) → metamitron (41394-05-2)

Conditions	Yield
Multi-step reaction with 5 steps 1: sulfuric acid / water / 20 - 40 °C 2: hydrogenchloride / 4 h / 45 - 60 °C 3: sulfuric acid / methanol / 8 h / 20 - 65 °C 4: hydrazine hydrate / 20 - 25 °C 5: butan-1-ol / 8 h / 20 - 132 °C / Reflux View Scheme

methyl 2-oxo-2-phenylacetate (15206-55-0) → metamitron (41394-05-2)

Conditions	Yield
Multi-step reaction with 3 steps 1: sulfuric acid / methanol / 8 h / 20 - 65 °C 2: hydrazine hydrate / 20 - 25 °C 3: butan-1-ol / 8 h / 20 - 132 °C / Reflux View Scheme

metamitron (41394-05-2) → 3-methyl-6-phenyl-1,2,4-triazin-5(4H)-one (36993-94-9)

Conditions	Yield
With tert.-butylhydroperoxide; 2,2′-((1E,1′E)-(ethane-1,2-diylbis(azanylylidene))bis(methanylylidene))diphenolmanganese(II) In dichloromethane for 6h; Ambient temperature; further oxidation agents;	90%
Stage #1: metamitron With titanium dioxide P25 In water for 0.833333h; Darkness; Stage #2: With sodium persulfate In water for 1h; pH=6.3; Kinetics; Concentration; Reagent/catalyst; pH-value; UV-irradiation;

metamitron (41394-05-2) → 1-acetyl-2-benzoylhydrazine (14331-27-2) + 3-methyl-6-phenyl-1,2,4-triazin-5(4H)-one (36993-94-9)

Conditions	Yield
With oxygen In water at 19.85℃; for 5h; pH=4 - 9; Quantum yield; Kinetics; Deamination; Photolysis;	A 20% B 80%

metamitron (41394-05-2) → 3-Methyl-6-phenyl-1,2,4-triazin-5(2H)-on (36993-94-9)

Conditions	Yield
With lead(IV) acetate In dichloromethane; acetic acid for 3h; Ambient temperature;	74%

metamitron (41394-05-2) → 3-Methyl-6-phenyl-1,2,4-triazin-5(2H)-thion (95927-17-6)

Conditions	Yield
With tetraphosphorus decasulfide In pyridine at 100℃; for 2h;	74%

metamitron (41394-05-2) → 4-amino-3-methyl-6-phenyl-2,3-dihydro-1,2,4-triazin-5(4H)-one

Conditions	Yield
With sodium tetrahydroborate In methanol for 48h; Ambient temperature;	60%

metamitron (41394-05-2) → 1,6-dihydro-4-amino-3-methyl-6-phenyl-1,2,4-triazin-5(4H)-one

Conditions	Yield
With acetate buffer In water; acetonitrile electrochemical reduction;	55%
With acetate buffer In water; acetonitrile Reduction; Electrochemical reaction;	55%

4-chloro-3-ethyl-1-methyl-1H-pyrazole-5-carboxylic acid + metamitron (41394-05-2) → C17H17ClN6O2

Conditions	Yield
With benzotriazol-1-ol; 1-ethyl-(3-(3-dimethylamino)propyl)-carbodiimide hydrochloride; triethylamine In N,N-dimethyl-formamide at 50℃; for 8h;	44%

Thiram (137-26-8) + metamitron (41394-05-2) → N(1),N(2)-di(3-methyl-5-oxo-6-phenyl-4,5-dihydro-1,2,4-triazin-4-yl)thiourea

Conditions	Yield
In ethanol for 5h; Heating;	37%

Upstream product

• 1603-79-8 phenylglyoxylic acid ethyl ester 
• 1068-57-1 acetic acid hydrazide 
• 15206-55-0 methyl 2-oxo-2-phenylacetate 
• 613-90-1 benzoyl cyanide 
• 56735-29-6 C₁₀H₁₂N₄O₂ 
• 611-73-4 Benzoylformic acid 
• 79848-81-0 N-acetyl-2-oxo-2-phenylacetamide 
• 56873-72-4 Acetohydrazid-hydrazon-hydrochlorid 

Downstream Products

• 14331-27-2 1-acetyl-2-benzoylhydrazine 
• 36993-94-9 3-methyl-6-phenyl-1,2,4-triazin-5(4H)-one 
• 95927-17-6 3-Methyl-6-phenyl-1,2,4-triazin-5(2H)-thion 
• 36993-94-9 3-Methyl-6-phenyl-1,2,4-triazin-5(2H)-on 

Relevant articles and documents

Preparation method of metamitron

The invention belongs to the technical field of organic matter preparation, and particularly discloses a preparation method of metamitron. The preparation method comprises the following steps: carrying out heat preservation on ethyl benzoylformate, hydrochloric acid and an acethydrazide solution at 25-28 DEG C for 2.5-3 hours, cooling, crystallizing, filtering and washing to obtain 2-acethydrazide ethyl benzoylformate; then mixing with methanol to prepare a mixed solution, adding hydrazine hydrate at 16-20 DEG C, and reacting to obtain 2-acethydrazide hydrazone-2-phenyl-acethydrazide; then adding methanol and sodium acetate, heating and refluxing at 90-94 DEG C for 8-9 hours, and cooling for 1.8-2.2 hours to obtain metamitron. According to the method, the preparation temperature and the preparation time of the 2-acethydrazide benzoyl ethyl formate are reduced, and the yield of metamitron is increased.

Production method of metamitron

The invention discloses a production method of metamitron. The production method is characterized by comprising the following steps that benzoyl cyanide is hydrolyzed under the condition of H2SO4, and is then alcoholized into ester; hydrazine hydrate and methyl acetate take reaction to generate acetyl hydrazine hydrate; methyl benzoylformate and the acetyl hydrazine hydrate take reaction to generate hydrazine hydrate ester under the condition of H2SO4; hydrazine hydrate ester suspension and hydrazine hydrate take reaction; acyl is subjected to hydrazine treatment again to generate benzoyl hydrazine, and byproducts of methyl alcohol and water are generated; the benzoyl hydrazine is subjected to distillation, backflow, dehydration, cyclization and crystallization under the condition with a butanol solvent and a catalyst to generate the metamitron. The production method has the advantages that the cost of phase transfer catalysts is low; the cost of sodium benzoate is lower than that of sodium acetate, so that the production cost is reduced.

Hydrazidines, IV. - Reaction of Hydrazidines with 1,2-Bifunctional Compounds

Hydrazide hydrazones 1 react with 1,2-bifunctional compounds (2, 21, 23, 26, 30, 32) to give preferentially 4-amino-1,2,4-triazines (9, 13, 22, 25, 27, 31, 35).Some reactions of these substances are described.