Novel forms of sulfuron-methyl, processes for their preparation and uses thereof
A kind of technology of sulfosulfuron-methyl, dimethylpyrimidine, applied in the new form of sulfosulfuron-methyl, its preparation and use field
- Summary
- Abstract
- Description
- Claims
- Application Information
AI Technical Summary
Problems solved by technology
Method used
Image
Examples
Embodiment 1
[0098] Example 1: Preparation of Amorphous Sulfosulfuron-methyl as disclosed in EP 0030138 (Example 1 and Example 3, with minor modifications)
[0099] A stirred mixture containing 157 g methyl 2-sulfamoylbenzoate, 73 g butyl isocyanate, 0.3 g 1,4-diazabicyclo[2.2.2]octane, and 1.0 L xylene was heated to reflux Lasts an hour and a half. Then, phosgene gas was introduced into the system under a dry ice reflux condenser to lower the reaction temperature to 120°C. This addition was continued until the reflux temperature remained at 120°C without further addition of phosgene. Then, the temperature of the reaction mixture was raised to 136°C (by removing the dry ice reflux condenser), after which the reaction mixture was cooled to room temperature and filtered. Evaporation of the filtrate yielded the desired crude methyl 2-(isocyanatosulfonyl)benzoate, which could be purified by pressure distillation at 132°C-138°C.
[0100] Methyl 2-(isocyanatosulfonyl)benzoate (14.1 g) and 5.7...
Embodiment 2
[0102] Example 2: Preparation of Sulfosulfuron-methyl Crystal Modification I from Acetone
[0103] A sample of sulfosulfuron-methyl (3 g) was placed in a three neck round bottom flask along with acetone (100 mL) and the resulting slurry was heated to 56°C to 58°C to obtain a homogeneous solution. The homogeneous solution was stirred at 56°C to 58°C for 2 hours and insoluble particles (if any) were filtered. The resulting solution was slowly cooled to room temperature. On cooling, fine crystals formed and the resulting multiphase mixture was stirred at 10°C to 20°C for 2 hours while cooling. The slurry was then filtered and washed with cold acetone (10 mL). The filtered crystals were vacuum dried at 40°C to remove residual acetone from the crystallized product. The crystallized product thus obtained had a purity of about 98%, and the yield of the recovered product as crystals was found to be about 85%.
[0104] The obtained crystals were analyzed by X-RPD, IR spectroscopy a...
Embodiment 3
[0110] Example 3: Preparation of Sulfosulfuron-Methyl Crystal Modification I from Dichloromethane
[0111] A sample of metsulfuron-methyl (6 g) was placed in a three neck round bottom flask along with dichloromethane (100 mL) and the resulting slurry was heated to 35°C-37°C to obtain a homogeneous solution. The resulting hot solution was stirred at 35°C-37°C for 2 hours and filtered to remove insolubles (if any), then the solution was slowly cooled to ambient temperature. The desired crystalline product precipitated out as fine crystals during cooling and the mixture was stirred between 10°C and 20°C for 2 hours. The slurry was then filtered, washed with cold dichloromethane (10 mL), and dried under vacuum at 40°C to remove residual dichloromethane from the crystals. The crystals thus obtained had a purity of about 98%, and the recovery yield was found to be about 86%. The crystal modification I of Sulfosulfuron-methyl was obtained.
[0112] The DSC thermogram of the sulfos...
PUM
| Property | Measurement | Unit |
|---|---|---|
| melting point | aaaaa | aaaaa |
Abstract
Description
Claims
Application Information
Login to View More