Preparation method of penoxsulam

A technology for penoxsulam and trifluoromethylbenzenesulfonyl chloride is applied in the field of preparation of penoxsulam, and can solve the problems of troublesome DMSO anhydrous treatment and recovery operations, inconvenient industrial application, low production efficiency, and the like, Achieving the effect of avoiding the use of expensive or highly toxic agents or solvents, low cost and cost saving

Inactive Publication Date: 2015-03-11
CHANGZHOU UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0010] (1) DMSO anhydrous treatment and recovery operations are cumbersome and difficult to achieve;
[0011] (2) The expensive and highly toxic reagent 18-crown-6 is used in the synthetic method reported by CN102020647, which brings a lot of inconvenience to industrial application;
[0012] (3) The synthesis method reported in US20050215570 has a long reaction time, resulting in low production efficiency;
[0013] (4) The synthesis method product yield reported by Timothy C etc. is too low

Method used

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  • Preparation method of penoxsulam
  • Preparation method of penoxsulam
  • Preparation method of penoxsulam

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0027]

[0028] At room temperature, add compound (II) (0.5mol) and anhydrous tetrahydrofuran (1L) into a 3L three-necked flask, add lithium diisopropylamide tetrahydrofuran solution (2.5mol / L, 300mL), stir for 10min, and dropwise add Compound (I) in tetrahydrofuran (2.5mol / L, 180mL), after the addition is complete, stir at room temperature. The reaction time is usually 30-60min until the raw material (I) or (II) is consumed. After the reaction, recover tetrahydrofuran, add 600mL of 95% ethanol to the residue, stir for 15min, filter, then stir the filter cake with 600mL of water for 10min, filter, and dry the filter cake to obtain the target product with a yield of 91%, mp: 223-224°C.

[0029] Confirmation of product structure: 1 H NMR (DMSO-d 6 ), δ: 11.88(s, 1H), 7.76(t, J=8.2Hz, 1H), 7.63(m, 3H), 6.51(t×t, J=4.2, 54.9Hz, 1H), 4.47(t×t d, J=3.8, 13.7Hz, 2H), 4.02(s, 3H), 3.84(s, 3H); ESI–MS: m / z 482 ([M-H - ]).

Embodiment 2

[0031] Using the method of Example 1, different non-nucleophilic bases or weak nucleophilic bases were used instead to synthesize the penoxsulam product. The results are shown in the following table:

[0032]

[0033]

[0034]

[0035]

[0036]

[0037]The above results show that: in the penoxsulam synthesis process method of the present invention, multiple non-nucleophilic bases or weak nucleophilic bases have good applicability to the synthetic reaction, and in (II), the base molar ratio is 1: The product yield is higher in the range of 1-1:2 process conditions, which is 87%-96%. When the consumption of alkali continued to increase (as the molar ratio was 1:3), the yield increase was very small, and the economic benefit brought by the increase in yield was less than the increased raw material cost, and the total economic benefit declined, so (II) , The molar ratio of the base is 1:1 to 1:5, preferably 1:1 to 1:2.

Embodiment 3

[0039] Using the method of Example 1, using lithium diisopropylamide as the base, changing different solvents and temperatures, the penoxsulam product was synthesized, and the results obtained are as follows:

[0040]

[0041]

[0042]

[0043]

[0044]

[0045] The above results show that: the reaction of the present invention also has good tolerance to different solvents, obtains high yields in various solvents, and has a relatively high temperature tolerance range, wherein the yield of 20 ° C to 50 ° C ideal.

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Abstract

The invention provides a preparation method of penoxsulam, and belongs to the technical field of pesticide synthesis. The penoxsulam is prepared through condensation reactions between 2-(2,2-difluoroethoxy)-6-trifluoromethyl benzene sulfonyl chloride (I) and 5,8-dimethoxy-[1,2,4]triazole[1,5-c]pyrimidine-2-amine (II) in the presence of a non-nucleophilic alkali or weakly-nucleophilic alkali. The synthesis time is reduced from reported 4 hours or more to 30 to 60 minutes, the product yield is 84 to 96%, and thus the production efficiency and product yield are prominently improved. Furthermore, the raw material prices are low, and the production cost is low. In the reaction process, no highly-toxic raw material or medicament is used, the material post treatment is simple, the generation amount of waste gas, waste liquid, and waste solid is small, and the treatment on the wastes is convenient, so the provided method is accord with the environment protection requirements and is suitable for industrial production and applications.

Description

technical field [0001] The invention relates to a new method for preparing penoxsulam, which belongs to the technical field of pesticide synthesis. Background technique [0002] Penoxsulam, chemical name: 2-(2,2-difluoroethoxy)-6-trifluoromethyl-N-(5,8-dimethoxy-[1,2,4] Triazolo[1,5-c]pyrimidin-2-yl)benzenesulfonamide, common name: Penoxsulam, trade name: Daojie, CAS registration number: 219714-96-2, its structural formula is as follows: [0003] [0004] Chemical structure of penoxsulam [0005] Penoxsulam (Peoxsulam) is an outstanding representative of sulfonylurea (amine) herbicides. It is a post-emergence herbicide successfully developed by Dow Agro Sciences in the United States. It inhibits acetolactate synthase (Activity of ALS). It was officially registered with the US Environmental Protection Agency (EPA) in September 2004, and then promoted and applied in the rice-growing areas of the southern United States, and entered my country in 2008. Penoxsulam herbicid...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D487/04
CPCC07D487/04
Inventor 张跃辜顺林严生虎刘建武徐思田沈介发马晓明陈代祥樊白白
Owner CHANGZHOU UNIV
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