210631-68-8

Basic information

• Product Name: TOPRAMEZONE
• Synonyms: TOPRAMEZONE;bas 670;[3-(4,5-Dihydro-3-isoxazolyl)-2-methyl-4-(methylsulfonyl)phenyl](5-hydroxy-1-methyl-1H-pyrazol-4-yl)methanone;Hsdb 7500;Topramezone [iso]
• CAS NO: 210631-68-8
• Molecular Formula: C₁₆H₁₇N₃O₅S
• Molecular Weight: 363.39
• Mol File: 210631-68-8.mol
• Article Data: 12

Chemical Properties

• Boiling Point: 590.491°C at 760 mmHg
• Flash Point: 310.918°C
• Appearance: /
• Density: 1.492g/cm³
• Vapor Pressure: 0mmHg at 25°C
• Refractive Index: 1.67
• PKA: 6.35±0.50(Predicted)
• CAS DataBase Reference: TOPRAMEZONE(CAS DataBase Reference)
• NIST Chemistry Reference: TOPRAMEZONE(210631-68-8)
• EPA Substance Registry System: TOPRAMEZONE(210631-68-8)

Safety Data

• Hazard Codes: T,N
• Statements: 61-50/53
• Safety Statements: 53-45-60-61
• RIDADR: UN3077 9/PG 3
• WGK Germany: 1
• Hazardous Substances Data: 210631-68-8(Hazardous Substances Data)

Usage

Uses

Topramezone is a herbicide that belongs to the class of pyrazolones or benzoylpyrazoles. It can be used to control broad leaved weeds and grass weeds in maize crop protection.

Definition

ChEBI: An aromatic ketone that is phenyl 1H-pyrazol-4-yl ketone in which the pyrazolyl group is substituted at positions 1 and 5 by methyl and hydroxy groups, respectively, and in which the phenyl group is substituted at positions 2, 3, and 4 b methyl, 4,5-dihydro-1,2-oxazol-3-yl, and methylsulfonyl groups, respectively. A potent inhibitor of 4-hydroxyphenylpyruvate dioxygenase (HPPD) that is rapily metabolised by corn to non-active substances, it is used as a herbicide for the treatment of broa leaf weeds.

InChI:InChI=1/C16H17N3O5S/c1-9-10(15(20)11-8-17-19(2)16(11)21)4-5-13(25(3,22)23)14(9)12-6-7-24-18-12/h4-5,8,21H,6-7H2,1-3H3

Synthetic route

1,4-dioxane (123-91-1) + 3-(3-bromo-2-methyl-6-(methylsulfonyl)phenyl)-4,5-dihydroisoxazole (247922-29-8) + 1-methyl-5-hydroxypyrazole (33641-15-5) → topramezone (210631-68-8)

Conditions	Yield
With carbon monoxide; potassium carbonate; triethylamine; triphenylphosphine; palladium(II) chloride In water	100%
With hydrogenchloride; potassium carbonate; triethylamine; bis(triphenylphosphine)palladium(II) dichloride In water

[3-(4,5-dihydro-1,2-oxazol-3-yl)-4-methylsulfonyl-2-methylphenyl](5-methoxy-1-methylpyrazole-4-yl)methanone → topramezone (210631-68-8)

Conditions	Yield
With hydrogen bromide; methyl(tri-n-octyl)ammonium bromide for 3h; Reagent/catalyst; Reflux;	93.5%

3-(3-bromo-2-methyl-6-(methylsulfonyl)phenyl)-4,5-dihydroisoxazole (247922-29-8) + formyl radical (2597-44-6) + 1-methyl-5-hydroxypyrazole (33641-15-5) → topramezone (210631-68-8)

Conditions	Yield
Stage #1: 3-(3-bromo-2-methyl-6-(methylsulfonyl)phenyl)-4,5-dihydroisoxazole With potassium carbonate In 1,4-dioxane Reflux; Stage #2: 1-methyl-5-hydroxypyrazole With triphenylphosphine; sodium iodide In 1,4-dioxane at 60℃; for 0.5h; Stage #3: formyl radical With palladium on activated charcoal In 1,4-dioxane at 120℃; under 11251.1 Torr; for 20h; Reagent/catalyst; Temperature;	84.4%

3-(4,5-dihydroisoxazol-3-yl)-4-methylsulfonyl-2-methylbenzoic acid (223646-24-0) + 1-methyl-5-hydroxypyrazole (33641-15-5) → topramezone (210631-68-8)

Conditions	Yield
Stage #1: 3-(4,5-dihydroisoxazol-3-yl)-4-methylsulfonyl-2-methylbenzoic acid With pyridine; thionyl chloride In benzene for 3h; Reflux; Stage #2: 1-methyl-5-hydroxypyrazole With triethylamine In 1,4-dioxane at 20℃; for 3h; Stage #3: With potassium carbonate for 6h; Reflux;	81.46%
Stage #1: 3-(4,5-dihydroisoxazol-3-yl)-4-methylsulfonyl-2-methylbenzoic acid With pyridine; thionyl chloride In toluene for 3h; Reflux; Stage #2: 1-methyl-5-hydroxypyrazole With triethylamine In 1,4-dioxane at 20℃; for 3h;	80.5%
Stage #1: 3-(4,5-dihydroisoxazol-3-yl)-4-methylsulfonyl-2-methylbenzoic acid With thionyl chloride for 2h; Reflux; Stage #2: With triethylamine In 1,2-dichloro-ethane at 20 - 30℃; for 0.5h; Stage #3: 1-methyl-5-hydroxypyrazole In 1,2-dichloro-ethane for 4h; Reflux;	20.87%

5-hydroxy-1-methyl-1H-pyrazole hydrochloride + 3-(3-bromo-2-methyl-6-(methylsulfonyl)phenyl)-4,5-dihydroisoxazole (247922-29-8) + carbon monoxide (201230-82-2) → topramezone (210631-68-8)

Conditions	Yield
With potassium carbonate; triethylamine; triphenylphosphine; palladium dichloride In 1,4-dioxane at 130℃; under 7500.75 Torr; for 10h; Inert atmosphere;	70%

5-hydroxy-1-methyl-1H-pyrazole hydrochloride + 3-(4,5-dihydroisoxazol-3-yl)-4-methylsulfonyl-2-methylbenzoyl chloride (223646-31-9) + 2-hydroxy-2-methylpropanenitrile (75-86-5) → topramezone (210631-68-8)

Conditions	Yield
With triethylamine In methanol; chloroform

3-(3-bromo-2-methyl-6-(methylsulfonyl)phenyl)-4,5-dihydroisoxazole (247922-29-8) + carbon monoxide (201230-82-2) + 1-methyl-5-hydroxypyrazole (33641-15-5) → topramezone (210631-68-8)

Conditions	Yield
With potassium carbonate; triphenylphosphine; palladium dichloride In 1,4-dioxane at 130℃; under 11251.1 Torr;

1-methyl-5-methoxy-4-pyrazolecarboxylic acid → topramezone (210631-68-8)

Conditions	Yield
Multi-step reaction with 4 steps 1.1: thionyl chloride / toluene / Reflux 1.2: 5 h / 0 °C 2.1: magnesium / tetrahydrofuran / 5 h / 60 °C / Inert atmosphere 2.2: 1 h / 10 °C / Inert atmosphere 3.1: sodium tungstate (VI) dihydrate; dihydrogen peroxide; acetic acid / 3 h / 60 °C 4.1: methyl(tri-n-octyl)ammonium bromide; hydrogen bromide / 3 h / Reflux View Scheme

N,5-dimethoxy-N,1-dimethyl-1H-pyrazole-4-carboxamide → topramezone (210631-68-8)

Conditions	Yield
Multi-step reaction with 3 steps 1.1: magnesium / tetrahydrofuran / 5 h / 60 °C / Inert atmosphere 1.2: 1 h / 10 °C / Inert atmosphere 2.1: sodium tungstate (VI) dihydrate; dihydrogen peroxide; acetic acid / 3 h / 60 °C 3.1: methyl(tri-n-octyl)ammonium bromide; hydrogen bromide / 3 h / Reflux View Scheme

3-((2-methyl)-6-methylthiophenyl)-4,5-dihydroisoxazole (250592-91-7) → topramezone (210631-68-8)

Conditions	Yield
Multi-step reaction with 3 steps 1.1: N,N,N,N,-tetramethylethylenediamine; n-butyllithium / ethyl acetate; hexane / 3 h / 0 °C / Reflux 1.2: 2 h / 0 - 20 °C 2.1: acetic acid; dihydrogen peroxide / 30 h / 30 °C 3.1: pyridine; thionyl chloride / toluene / 3 h / Reflux 3.2: 3 h / 20 °C View Scheme

3-(2-methyl-6-aminophenyl)-4,5-dihydroisoxazole (250592-89-3) → topramezone (210631-68-8)

Conditions	Yield
Multi-step reaction with 4 steps 1.1: nitroso isopentyl ester; copper / 2 h / 30 °C / Cooling with ice 2.1: N,N,N,N,-tetramethylethylenediamine; n-butyllithium / ethyl acetate; hexane / 3 h / 0 °C / Reflux 2.2: 2 h / 0 - 20 °C 3.1: acetic acid; dihydrogen peroxide / 30 h / 30 °C 4.1: pyridine; thionyl chloride / toluene / 3 h / Reflux 4.2: 3 h / 20 °C View Scheme

3-((2-methyl)-6-nitrophenyl)-4,5-dihydroisoxazole (250592-88-2) → topramezone (210631-68-8)

Conditions

Yield

Multi-step reaction with 5 steps 1.1: 5%-palladium/activated carbon; hydrogen / dichloromethane / 10 h / 25 - 30 °C 2.1: nitroso isopentyl ester; copper / 2 h / 30 °C / Cooling with ice 3.1: N,N,N,N,-tetramethylethylenediamine; n-butyllithium / ethyl acetate; hexane / 3 h / 0 °C / Reflux 3.2: 2 h / 0 - 20 °C 4.1: acetic acid; dihydrogen peroxide / 30 h / 30 °C 5.1: pyridine; thionyl chloride / toluene / 3 h / Reflux 5.2: 3 h / 20 °C View Scheme

2-methyl-6-nitrosobenzaldehyde oxime → topramezone (210631-68-8)

Conditions

Yield

Multi-step reaction with 6 steps 1.1: acetic acid; chlorine / 4 h / Inert atmosphere 1.2: 24 h / 6000.6 - 7500.75 Torr 2.1: 5%-palladium/activated carbon; hydrogen / dichloromethane / 10 h / 25 - 30 °C 3.1: nitroso isopentyl ester; copper / 2 h / 30 °C / Cooling with ice 4.1: N,N,N,N,-tetramethylethylenediamine; n-butyllithium / ethyl acetate; hexane / 3 h / 0 °C / Reflux 4.2: 2 h / 0 - 20 °C 5.1: acetic acid; dihydrogen peroxide / 30 h / 30 °C 6.1: pyridine; thionyl chloride / toluene / 3 h / Reflux 6.2: 3 h / 20 °C View Scheme

2,3-dimethylnitrobenzene (83-41-0) → topramezone (210631-68-8)

Conditions

Yield

Multi-step reaction with 7 steps 1.1: nitroso isopentyl ester; sodium methylate / N,N-dimethyl-formamide / 0.5 h / -40 - -35 °C 2.1: acetic acid; chlorine / 4 h / Inert atmosphere 2.2: 24 h / 6000.6 - 7500.75 Torr 3.1: 5%-palladium/activated carbon; hydrogen / dichloromethane / 10 h / 25 - 30 °C 4.1: nitroso isopentyl ester; copper / 2 h / 30 °C / Cooling with ice 5.1: N,N,N,N,-tetramethylethylenediamine; n-butyllithium / ethyl acetate; hexane / 3 h / 0 °C / Reflux 5.2: 2 h / 0 - 20 °C 6.1: acetic acid; dihydrogen peroxide / 30 h / 30 °C 7.1: pyridine; thionyl chloride / toluene / 3 h / Reflux 7.2: 3 h / 20 °C View Scheme

2,3-dimethyl-4-methanesulfonyl-1-chlorobenzene (250593-01-2) → topramezone (210631-68-8)

Conditions

Yield

Multi-step reaction with 5 steps 1.1: sodium ethanolate; n-Butyl nitrite / N,N-dimethyl-formamide / 2 h / -20 - -15 °C 2.1: N-chloro-succinimide / acetonitrile / 1 h / 45 - 60 °C 2.2: 3 h / 20 °C / 4500.45 Torr / Autoclave 3.1: copper(l) iodide / N,N-dimethyl-formamide / 24 h / 100 °C / Inert atmosphere 4.1: sulfuric acid / 12 h / 100 °C 5.1: thionyl chloride; pyridine / benzene / 3 h / Reflux 5.2: 3 h / 20 °C 5.3: 6 h / Reflux View Scheme

2-methyl-3-chloro-6-methanesulfonylbenzaldehyde oxime → topramezone (210631-68-8)

Conditions	Yield
Multi-step reaction with 4 steps 1.1: N-chloro-succinimide / acetonitrile / 1 h / 45 - 60 °C 1.2: 3 h / 20 °C / 4500.45 Torr / Autoclave 2.1: copper(l) iodide / N,N-dimethyl-formamide / 24 h / 100 °C / Inert atmosphere 3.1: sulfuric acid / 12 h / 100 °C 4.1: thionyl chloride; pyridine / benzene / 3 h / Reflux 4.2: 3 h / 20 °C 4.3: 6 h / Reflux View Scheme

3-[3-chloro-2-methyl-6-methylsulfonylphenyl]-4,5-dihydroisoxazole → topramezone (210631-68-8)

Conditions	Yield
Multi-step reaction with 3 steps 1.1: copper(l) iodide / N,N-dimethyl-formamide / 24 h / 100 °C / Inert atmosphere 2.1: sulfuric acid / 12 h / 100 °C 3.1: thionyl chloride; pyridine / benzene / 3 h / Reflux 3.2: 3 h / 20 °C 3.3: 6 h / Reflux View Scheme

2,3-dimethyl-4-methylsulfanylbromobenzene (250593-00-1) → topramezone (210631-68-8)

Conditions

Yield

Multi-step reaction with 6 steps 1.1: acetic acid; dihydrogen peroxide; sodium tungstate (VI) dihydrate / 2 h / 100 °C 2.1: sodium ethanolate; n-Butyl nitrite / N,N-dimethyl-formamide / 2.5 h / -20 - -15 °C 3.1: N-chloro-succinimide / acetonitrile / 1 h / 45 - 60 °C 3.2: 3 h / 20 °C / 4500.45 Torr / Autoclave 4.1: N,N-dimethyl-formamide / 8 h / 120 °C / Inert atmosphere 5.1: sulfuric acid / 12 h / 100 °C 6.1: thionyl chloride; pyridine / benzene / 3 h / Reflux 6.2: 3 h / 20 °C 6.3: 6 h / Reflux View Scheme

2,3-dimethyl-4-methanesulfonyl-1-bromobenzene (128277-66-7) → topramezone (210631-68-8)

Conditions

Yield

Multi-step reaction with 5 steps 1.1: sodium ethanolate; n-Butyl nitrite / N,N-dimethyl-formamide / 2.5 h / -20 - -15 °C 2.1: N-chloro-succinimide / acetonitrile / 1 h / 45 - 60 °C 2.2: 3 h / 20 °C / 4500.45 Torr / Autoclave 3.1: N,N-dimethyl-formamide / 8 h / 120 °C / Inert atmosphere 4.1: sulfuric acid / 12 h / 100 °C 5.1: thionyl chloride; pyridine / benzene / 3 h / Reflux 5.2: 3 h / 20 °C 5.3: 6 h / Reflux View Scheme

2-methyl-3-bromo-6-methanesulfonylbenzaldehyde oxime → topramezone (210631-68-8)

Conditions	Yield
Multi-step reaction with 4 steps 1.1: N-chloro-succinimide / acetonitrile / 1 h / 45 - 60 °C 1.2: 3 h / 20 °C / 4500.45 Torr / Autoclave 2.1: N,N-dimethyl-formamide / 8 h / 120 °C / Inert atmosphere 3.1: sulfuric acid / 12 h / 100 °C 4.1: thionyl chloride; pyridine / benzene / 3 h / Reflux 4.2: 3 h / 20 °C 4.3: 6 h / Reflux View Scheme

3-(3-bromo-2-methyl-6-(methylsulfonyl)phenyl)-4,5-dihydroisoxazole (247922-29-8) → topramezone (210631-68-8)

Conditions	Yield
Multi-step reaction with 3 steps 1.1: N,N-dimethyl-formamide / 8 h / 120 °C / Inert atmosphere 2.1: sulfuric acid / 12 h / 100 °C 3.1: thionyl chloride; pyridine / benzene / 3 h / Reflux 3.2: 3 h / 20 °C 3.3: 6 h / Reflux View Scheme

3-[3-cyano-2-methyl-6-methylsulfonylphenyl]-4,5-dihydroisoxazole → topramezone (210631-68-8)

Conditions	Yield
Multi-step reaction with 2 steps 1.1: sulfuric acid / 12 h / 100 °C 2.1: thionyl chloride; pyridine / benzene / 3 h / Reflux 2.2: 3 h / 20 °C 2.3: 6 h / Reflux View Scheme

1,2-dimethyl-3-(methylsulfanyl)benzene (66794-10-3) → topramezone (210631-68-8)

Conditions	Yield
Multi-step reaction with 7 steps 1.1: bromine / 1,2-dichloro-ethane / 2 h / 20 - 25 °C 2.1: acetic acid; dihydrogen peroxide; sodium tungstate (VI) dihydrate / 2 h / 100 °C 3.1: sodium ethanolate; n-Butyl nitrite / N,N-dimethyl-formamide / 2.5 h / -20 - -15 °C 4.1: N-chloro-succinimide / acetonitrile / 1 h / 45 - 60 °C 4.2: 3 h / 20 °C / 4500.45 Torr / Autoclave 5.1: N,N-dimethyl-formamide / 8 h / 120 °C / Inert atmosphere 6.1: sulfuric acid / 12 h / 100 °C 7.1: thionyl chloride; pyridine / benzene / 3 h / Reflux 7.2: 3 h / 20 °C 7.3: 6 h / Reflux View Scheme
Multi-step reaction with 7 steps 1.1: chlorobenzene; aluminum (III) chloride; sulfuryl dichloride / 2.33 h / 5 °C 2.1: acetic acid; dihydrogen peroxide; sodium tungstate (VI) dihydrate / 1.17 h / 100 °C 3.1: sodium ethanolate; n-Butyl nitrite / N,N-dimethyl-formamide / 2 h / -20 - -15 °C 4.1: N-chloro-succinimide / acetonitrile / 1 h / 45 - 60 °C 4.2: 3 h / 20 °C / 4500.45 Torr / Autoclave 5.1: copper(l) iodide / N,N-dimethyl-formamide / 24 h / 100 °C / Inert atmosphere 6.1: sulfuric acid / 12 h / 100 °C 7.1: thionyl chloride; pyridine / benzene / 3 h / Reflux 7.2: 3 h / 20 °C 7.3: 6 h / Reflux View Scheme

2,3-dimethyl-4-methylthio-1-chlorobenzene → topramezone (210631-68-8)

Conditions

Yield

Multi-step reaction with 6 steps 1.1: acetic acid; dihydrogen peroxide; sodium tungstate (VI) dihydrate / 1.17 h / 100 °C 2.1: sodium ethanolate; n-Butyl nitrite / N,N-dimethyl-formamide / 2 h / -20 - -15 °C 3.1: N-chloro-succinimide / acetonitrile / 1 h / 45 - 60 °C 3.2: 3 h / 20 °C / 4500.45 Torr / Autoclave 4.1: copper(l) iodide / N,N-dimethyl-formamide / 24 h / 100 °C / Inert atmosphere 5.1: sulfuric acid / 12 h / 100 °C 6.1: thionyl chloride; pyridine / benzene / 3 h / Reflux 6.2: 3 h / 20 °C 6.3: 6 h / Reflux View Scheme

3-[2-methyl-6-bromophenyl]-4,5-dihydroisoxazole → topramezone (210631-68-8)

Conditions	Yield
Multi-step reaction with 3 steps 1: copper(l) chloride / tetrahydrofuran; N,N-dimethyl-formamide / 12 h / 0 °C / Inert atmosphere 2: iron(III) chloride; N-Bromosuccinimide / tetrahydrofuran / 2 h / 50 - 65 °C / Inert atmosphere 3: triethylamine; potassium carbonate; palladium dichloride; triphenylphosphine / 1,4-dioxane / 10 h / 130 °C / 7500.75 Torr / Inert atmosphere View Scheme

C8H8BrNO → topramezone (210631-68-8)

Conditions

Yield

Multi-step reaction with 4 steps 1: iron(III) chloride; N-chloro-succinimide / tetrahydrofuran / 5 h / 60 °C / 7500.75 Torr / Inert atmosphere 2: copper(l) chloride / tetrahydrofuran; N,N-dimethyl-formamide / 12 h / 0 °C / Inert atmosphere 3: iron(III) chloride; N-Bromosuccinimide / tetrahydrofuran / 2 h / 50 - 65 °C / Inert atmosphere 4: triethylamine; potassium carbonate; palladium dichloride; triphenylphosphine / 1,4-dioxane / 10 h / 130 °C / 7500.75 Torr / Inert atmosphere View Scheme

2-bromo-6-methylbenzaldehyde (176504-70-4) → topramezone (210631-68-8)

Conditions

Yield

Multi-step reaction with 5 steps 1: hydroxylamine hydrochloride; sodium hydroxide / tetrahydrofuran; water / 6 h / 30 °C / Inert atmosphere 2: iron(III) chloride; N-chloro-succinimide / tetrahydrofuran / 5 h / 60 °C / 7500.75 Torr / Inert atmosphere 3: copper(l) chloride / tetrahydrofuran; N,N-dimethyl-formamide / 12 h / 0 °C / Inert atmosphere 4: iron(III) chloride; N-Bromosuccinimide / tetrahydrofuran / 2 h / 50 - 65 °C / Inert atmosphere 5: triethylamine; potassium carbonate; palladium dichloride; triphenylphosphine / 1,4-dioxane / 10 h / 130 °C / 7500.75 Torr / Inert atmosphere View Scheme

2-methylphenyl aldehyde (529-20-4) → topramezone (210631-68-8)

Conditions

Yield

Multi-step reaction with 6 steps 1: iron(III) chloride; N-Bromosuccinimide / ethyl acetate / 2 h / 45 °C / Inert atmosphere 2: hydroxylamine hydrochloride; sodium hydroxide / tetrahydrofuran; water / 6 h / 30 °C / Inert atmosphere 3: iron(III) chloride; N-chloro-succinimide / tetrahydrofuran / 5 h / 60 °C / 7500.75 Torr / Inert atmosphere 4: copper(l) chloride / tetrahydrofuran; N,N-dimethyl-formamide / 12 h / 0 °C / Inert atmosphere 5: iron(III) chloride; N-Bromosuccinimide / tetrahydrofuran / 2 h / 50 - 65 °C / Inert atmosphere 6: triethylamine; potassium carbonate; palladium dichloride; triphenylphosphine / 1,4-dioxane / 10 h / 130 °C / 7500.75 Torr / Inert atmosphere View Scheme

3-[2-methyl-6-(methylsulfonyl)phenyl]-4,5-dihydroisoxazole → topramezone (210631-68-8)

Conditions	Yield
Multi-step reaction with 2 steps 1: iron(III) chloride; N-Bromosuccinimide / tetrahydrofuran / 2 h / 50 - 65 °C / Inert atmosphere 2: triethylamine; potassium carbonate; palladium dichloride; triphenylphosphine / 1,4-dioxane / 10 h / 130 °C / 7500.75 Torr / Inert atmosphere View Scheme

Upstream product

• 123-91-1 1,4-dioxane 
• 247922-29-8 3-(3-bromo-2-methyl-6-(methylsulfonyl)phenyl)-4,5-dihydroisoxazole 
• 33641-15-5 1-methyl-5-hydroxypyrazole 
• 33641-16-6 5-hydroxy-1-methyl-1H-pyrazole hydrochloride 
• 223646-31-9 3-(4,5-dihydroisoxazol-3-yl)-4-methylsulfonyl-2-methylbenzoyl chloride 
• 75-86-5 2-hydroxy-2-methylpropanenitrile 
• 223646-24-0 3-(4,5-dihydroisoxazol-3-yl)-4-methylsulfonyl-2-methylbenzoic acid 
• 250592-91-7 3-((2-methyl)-6-methylthiophenyl)-4,5-dihydroisoxazole 
• 250592-89-3 3-(2-methyl-6-aminophenyl)-4,5-dihydroisoxazole 
• 250592-88-2 3-((2-methyl)-6-nitrophenyl)-4,5-dihydroisoxazole 
• 83-41-0 2,3-dimethylnitrobenzene 
• 52331-02-9 1,4-dichloro-2,3-dimethyl-benzene 
• 95-47-6 o-xylene 
• 201230-82-2 carbon monoxide 

Relevant articles and documents

Preparation method of topramezone

The invention relates to a preparation method of topramezone. The method comprises: carrying out reaction on a compound I (3-[3-bromo-2-methyl-6-(methylthio)-phenyl]-4, 5-dihydroisoxazole) and a compound II (1-methyl-5-hydroxypyrazole) in the atmosphere of a copper catalyst, a ligand, an organic solvent, an alkali and a CO gas to prepare the topramezone, wherein the reaction temperature is controlled to be 25-120 DEG C, and the reaction time is 18-24 hours. The preparation method is simple and convenient to operate, the catalyst is cheap, the production cost is greatly reduced, the product yield is high, and the preparation method can be used for industrial production of topramezone.

Preparation method and application of topramezone

The invention discloses a preparation method and application of topramezone, and the preparation method comprises the following steps: taking 2-methylbenzaldehyde, a bromination reagent, a catalyst, hydroxylamine hydrochloride, an alkali, ethylene gas, a sulfonylation reagent and a preset solvent as reaction raw materials, and preparing 3-[3-bromo-methyl-6-(methylsulfonyl) phenyl]-4, 5-dihydroisoxazole through a first reaction process; taking diethyl malonate, triethyl orthoformate, nickel sulfate, monobasic saturated carboxylic acid, methylhydrazine, a hydrocarbon solvent, an ethanol solutionand hydrochloric acid as reaction raw materials, and carrying out a second reaction process to prepare 1-methyl-5-hydroxypyrazole; and taking the 3-[3-bromo-methyl-6-(methylsulfonyl) phenyl]-4, 5 dihydroisoxazole,-1-methyl-5-hydroxypyrazole, triethylamine, potassium carbonate, palladium chloride, triphenylphosphine, 1, 4-dioxane, water, a saturated NaHCO3 solution and a hydrochloric acid solutionas reaction raw materials, and carrying out a third reaction process to prepare the topramezone. The problems that a sulfur-containing intermediate can emit odor and the raw materials are difficult to obtain in the existing process are solved.

Topramezone intermediate and topramezone preparation method

The invention relates to the field of organic synthesis, in particular to a topramezone intermediate and a topramezone preparation method. The topramezone preparation method comprises the following steps: 3-[3-halogen-2-methyl-6-(methylsulfonyl)phenyl]-4, 5-dihydroisoxazole and cyanide are subjected to a substitution reaction to obtain 3-[3-cyano-2-methyl-6-(methylsulfonyl)phenyl]-4, 5-dihydroisoxazole; hydrolysis reaction is performed on 3-[3-cyano-2-methyl-6-(methylsulfonyl)phenyl]-4, 5-dihydroisoxazole under the action of acid or alkali to obtain 2-methyl-3-(4, 5-dihydroisoxazole-3-yl)-4-methylsulfonyl benzoic acid; and 2-methyl-3-(4, 5-dihydroisoxazole-3-yl)-4-methylsulfonyl benzoic acid and 1-methyl-5-hydroxypyrazole are condensed and rearranged to generate topramezone. According to the topramezone intermediate and the topramezone preparation method provided by the invention, the use of an expensive palladium catalyst and a dangerous butyl lithium reagent is avoided, the yield isrelatively high, the cost is reduced, the process is simplified, the defects in the prior art are overcome, and the industrial value is achieved.