Preparation method of white thiophanate methyl

A technology of thiophanate-methyl and white, which is applied in the field of preparation of white thiophanate-methyl, which can solve the problems of easy oxidation and darkening of color, and achieve the effects of low production cost, simple operation and low investment in equipment

Inactive Publication Date: 2010-08-18
HUNAN CHEM RES INST
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the colorless crystalline o-phenylenediamine is easily oxidized in air and sunlight to darken the color, and the resulting thiophanate-methyl is usually gray

Method used

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  • Preparation method of white thiophanate methyl
  • Preparation method of white thiophanate methyl
  • Preparation method of white thiophanate methyl

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0017] Add 180ml dichloroethane, 16.4g dark brown o-phenylenediamine (Mr=108, 0.15mol, content 99%, industrial product) and 0.17g silicon alginate, heat up to reflux, and after reflux for 1 hour, filter while hot, and cool the filtrate for later use. Add 26.3g sodium thiocyanate (Mr=81, 0.318mol, 98%, industrial product), 50mL dichloroethane and 1.0g Catalyst N, N-dimethylaniline (98%, industrial product), start stirring, and drop 30.7g (Mr=94.5, 0.318mol, 98%, industrial product) methyl chloroformate into the reaction flask at room temperature , After dropping, incubate and react at 40-45°C for 30 minutes. After the heat preservation is completed, reduce the temperature of the system to below 20°C, and add the mixture of o-phenylenediamine and organic solvent obtained after the decolorization treatment in batches. The reaction is exothermic violently, and the temperature is controlled below 60°C. Timed reaction for 1 hour, cooling to below 20°C, filtering, adding 200ml of w...

Embodiment 2

[0019] Add 180ml dichloroethane, 16.4g light brown o-phenylenediamine (Mr=108, 0.15mol, 99%, industrial product) and 0.49g silicon alginate, heat up to reflux, and after reflux for 1 hour, filter while hot, and cool the filtrate for later use. Add 26.3g sodium thiocyanate (Mr=81, 0.318mol, 98%, industrial product), 50mL dichloroethane and 1.0g Catalyst N, N-dimethylaniline (98%, industrial product), start stirring, and drop 30.7g (Mr=94.5, 0.318mol, 98%, industrial product) methyl chloroformate into the reaction flask at room temperature , After dropping, incubate and react at 40-45°C for 30 minutes. After the heat preservation is completed, reduce the temperature of the system to below 20°C, and add the mixture of o-phenylenediamine and organic solvent obtained after the decolorization treatment in batches. The reaction is exothermic violently, and the temperature is controlled below 60°C. Time the reaction for 1 hour, cool down to below 20°C, filter, add 200ml of water to ...

Embodiment 3

[0021] The 99% o-phenylenediamine industrial product that handles is brown, and organic solvent is ethyl acetate, and all the other are identical with embodiment 1, obtain thiophanate-methyl product 50.2g, content 97.2%, yield 95.1% (based on o-phenylenediamine Diamine meter), whiteness: 85.3%.

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Abstract

The invention discloses a preparation method of white thiophanate methyl, wherein diatomite is used as a decoloring agent, a color o-phenylenediamine industrial product is dissolved in an organic solvent, decolored by reflux and filtered to obtain a mixture of colorless o-phenylenediamine and the organic solvent, and the mixture is directly used in the synthesis of thiophanate methyl to obtain white tropine with whiteness of above 85 percent. The invention has less equipment investment, simple operation, low production cost, no three wastes and suitability for industrialized production.

Description

Technical field: [0001] The invention relates to a preparation method of white thiophanate-methyl. Background technique: [0002] Common name: thiophanate-methyl (thiophanate-methyl), trade name: Topsin-M (Topsin-M) for short, chemical name is 1,2-bis(3-methoxycarbonyl-2-thiourea base) benzene. Physical and chemical properties: the pure product is a colorless crystal, and the original powder (content about 93%) is a light yellow crystal. The specific gravity is 1.5 (20°C), the melting point is 172°C (decomposition), and the vapor pressure is 949.1×10-8Pa (25°C). Almost insoluble in water, soluble in acetone, methanol, ethanol, chloroform and other organic solvents. Stable to acid and alkali. According to the classification standard of pesticide toxicity in China, thiophanate-methyl is a low-toxic fungicide. The acute oral LD50 in rats is 7500 mg / kg (male) and 6640 mg / kg (female). The acute oral LD50 of mice is 1510 mg / kg (male) and 3400 mg / kg (female). The acute percu...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C335/28
Inventor 毛春晖陈明庞怀林刘伟杨彬
Owner HUNAN CHEM RES INST
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