Preparation of bactericide propiconazole

A technology of propiconazole and fungicide, applied in the field of preparation of propiconazole, can solve problems such as air pollution, difficulty in purification and separation, and loss, and achieve the effects of avoiding recovery loss, high total yield, and simple process

Inactive Publication Date: 2008-12-17
JIANGSU SEVENCONTINENT GREEN CHEM CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0004] The weak point of above-mentioned patent method is: (1) in the preparation process of starting material 2,4-dichlorophenyl-alpha-bromomethyl ketone, be difficult to reach ideal quality and yield, main reason is that there is 8% of 2,4-dichlorophenyl-α, the by-product of α-dibromomethyl ketone, and 6% of 2,4-dichloroacetophenone can not react, resulting in purification and separation difficulties, thus greatly Affec

Method used

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  • Preparation of bactericide propiconazole

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0037] (1) Preparation of ketal

[0038] 450g (99%, 2.36mol) 2,4-dichloroacetophenone, 22.5g p-toluenesulfonic acid, 262g (98%, 2.47mol) 1,2-pentanediol and 900g hexamethylene, drop into respectively In the 2L reaction bottle of the water tank and the condenser, stir and heat up to solvent reflux, and dehydrate at normal pressure for 10 hours. GC analysis shows that the content of 2,4-dichloroacetophenone is less than 0.5%, and the reaction is completed and cooled to below 40°C. The obtained The ketal was directly used in the next step reaction.

[0039] (2) Preparation of bromoketal

[0040] To the above reaction solution, slowly add 390g (99%, 2.41mol) of liquid bromine dropwise, the dropping time is controlled within 1 to 3 hours, and the temperature is controlled at 25 to 30°C. The hydrogen bromide tail gas released during the reaction is absorbed by water . After the dropwise addition was completed, stirring was continued for 1 hour to end. Neutralize the residual aci...

Embodiment 2

[0046] (1) Preparation of ketal

[0047] 450g (99%, 2.36mol) 2,4-dichloroacetophenone, 22.5g p-toluenesulfonic acid, 262g (98%, 2.47mol) 1,2-pentanediol and 900g benzene, drop into water trap respectively In a 2L reaction flask with a condenser, stir and heat up to solvent reflux, and dehydrate at normal pressure for 10 hours. GC analysis shows that the content of 2,4-dichloroacetophenone is less than 0.5%. After the reaction is completed, it is cooled to below 40°C. The ketone was directly used in the next reaction.

[0048] (2) Preparation of bromoketal

[0049] To the above reaction solution, slowly add 390g (99%, 2.41mol) of liquid bromine dropwise, the dropping time is controlled within 1 to 3 hours, and the temperature is controlled at 25 to 30°C. The hydrogen bromide tail gas released during the reaction is absorbed by water . After the dropwise addition was completed, stirring was continued for 1 hour to end. Neutralize the residual acid in the system with 10% aque...

Embodiment 3

[0055] (1) Preparation of ketal

[0056] 450g (99%, 2.36mol) 2,4-dichloroacetophenone, 22.5g p-toluenesulfonic acid, 262g (98%, 2.47mol) 1,2-pentanediol and 900g hexamethylene, drop into respectively In the 2L reaction bottle of the water tank and the condenser, stir and heat up to solvent reflux, and dehydrate at normal pressure for 10 hours. GC analysis shows that the content of 2,4-dichloroacetophenone is less than 0.5%, and the reaction is completed and cooled to below 40°C. The obtained The ketal was directly used in the next step reaction.

[0057] (2) Preparation of bromoketal

[0058] To the above reaction solution, slowly add 390g (99%, 2.41mol) of liquid bromine dropwise, the dropping time is controlled within 1 to 3 hours, and the temperature is controlled at 25 to 30°C. The hydrogen bromide tail gas released during the reaction is absorbed by water . After the dropwise addition was completed, stirring was continued for 1 hour to end. Neutralize the residual aci...

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Abstract

The invention discloses a preparation method of propiconazole that is a bactericide, which comprises four steps: first of all, under the action of an acid catalyst, atmospheric refluxing dehydration is carried out to 2, 4-dichloroacetophenone and 1, 2-pentanediol which are in an organic solvent so as to obtain ketal reaction solution which then reacts with bromine to generate bromide ketal which then reacts with 1, 2, 4- triazole sylvite in a polar solvent under the action of a phase transfer catalyst to obtain a propiconazole crude product; finally, under the action of an antioxidant, the propiconazole crude product is distilled under high vacuum and high temperature to obtain the propiconazole finished product. The preparation method of the invention reduces the varieties and dosage of the solvents necessary for reactions as well as the yield of wastewater resulted from cleaning during the reactions, thus realizing the goal of clean production.

Description

technical field [0001] The invention relates to an agricultural fungicide, in particular to a preparation method of propiconazole. Background technique [0002] Propiconazole is 1-[2-(2,4-dichlorophenyl)-4-propyl-1,3-dioxolane-2-methyl]-1-hydrogen-1,2,4- Generic name for triazole. It is a systemic triazole fungicide with protective and therapeutic effects, which can be absorbed by roots, stems, and leaves, and can quickly conduct upwards in the plant to prevent and control ascomycetes, basidiomycetes, and half-knowledge fungi. It has a good control effect on wheat take-all, powdery mildew, rust, root rot, rice bad fungus, and banana leaf spot. [0003] U.S. Patent US4079062 (1979) application document discloses the synthetic method of series compounds such as propiconazole, and wherein propiconazole adopts 2,4-dichlorophenyl-alpha-bromomethyl ketone as starting raw material, through and 1 , 2-pentanediol is cyclized to obtain bromoketal, and then condensed with 1,2,4-tria...

Claims

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Application Information

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IPC IPC(8): C07D405/06A01P3/00
Inventor 周彬周斌陶伟周耀德
Owner JIANGSU SEVENCONTINENT GREEN CHEM CO LTD
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