- Convenient Synthesis of 2-(2,2-Difluoroethoxy)-6-(trifluoromethyl)-benzenesulfonyl Chloride, A Key Building Block of Penoxsulam
-
A convenient and efficient three-step synthesis of 2-(2,2-difluoroethoxy)-6-(trifluoromethyl)benzenesulfonyl chloride, the key building block of penoxsulam, is described. The main features of the synthesis include a regioselective lithiation and subsequent electrophilic substitution starting from commercially available 3-bromobenzotrifluoride to provide (2-bromo-6-(trifluoromethyl)phenyl)(propyl)sulfane, then a copper-catalyzed C-O coupling to introduce the difluoroethoxy moiety and chloroxidation conditions to give the desired sulfonyl chloride.
- Cui, Yu Ming,Huang, Shuai Shuai,Xu, Li Wen,Xu, Zheng,Yang, Ke Fang,Zheng, Zhan Jiang
-
-
Read Online
- Improved process for chloroxidation of aryl sulfides to aryl sulfonyl chlorides in commercial grade formic acid
-
This paper discusses the process advantages of using commercial grade formic acid as the solvent for chlorine gas oxidation of aryl sulfides to sulfonyl chlorides. Compared to chloroxidation in methylene chloride, the chloroxidation in formic acid gave a consistently higher yield and easy product isolation for a sulfonyl chloride intermediate which was used in the production of the sulfonamide herbicide, penoxsulam.
- Wang, Chen,Hamilton, Christopher,Meister, Phillip,Menning, Catherine
-
-
Read Online
- Synthesis method of 2-(2, 2-difluoroethyoxyl)-6-trifluoromethyl benzenesulfonyl chloride
-
The invention discloses a synthesis method of 2-(2, 2-difluoroethyoxyl)-6-trifluoromethyl benzenesulfonyl chloride. The preparation method comprises the following steps: dissolving 2-trifluoromethyl-4-nitro-bromobenzene in sulfuric acid, adding a halogenating reagent, and reacting at 50-100 DEG C for 1-8 hours; dissolving the obtained 2-bromo-3-trifluoromethyl-5-nitro-benzene halide in a solvent, and performing reduction in a reduction system; carrying out diazotization on the obtained 3-halo-4-bromo-5-trifluoromethyl-aniline, and then carrying out decomposition on the obtained 3-halo-4-bromo-5-trifluoromethyl-aniline; carrying out Grignard reaction on the obtained 2-bromo-3-trifluoromethyl-benzene halide, and then reacting with dialkyl disulfide; carrying out etherification reaction on the obtained 2-alkylthio-3-trifluorotoluene-benzene halide and 2, 2-difluoroethanol in an organic solvent under the action of an alkali; and reacting the obtained 2-(2, 2-difluoroethoxy)-6-trifluoromethyl-phenylalkyl sulfide with chlorine gas at 10-60 DEG C for 1-5 hours. The method is short in route, mild in condition, high in yield and suitable for industrial production.
- -
-
Paragraph 0058; 0074-0076
(2021/06/13)
-
- Synthesis method for 2-(2,2-difluoroethoxy)-6-(trifluoromethyl)benzenesulfonyl chloride
-
The invention relates to the technical field of organic synthesis and discloses a synthesis method for 2-(2,2-difluoroethoxy)-6-(trifluoromethyl)benzenesulfonyl chloride. The synthesis method is usedfor solving the problems of the existing synthesis of the 2-(2,2-difluoroethoxy)-6-(trifluoromethyl)benzenesulfonyl chloride that the route is relatively long and the total yield is relatively low. The synthesis method comprises the steps of subjecting a compound represented by a formula I to a reaction with a non-nucleophilic lithium reagent and dipropyl disulfide in a non-aprotic reagent so as to obtain a compound represented by a formula II, then, subjecting the compound represented by the formula II to a reaction with difluoroethanol in the presence of a strong base reagent, a copper catalyst and a cocatalyst so as to obtain a compound represented by a formula III, and then, subjecting the compound represented by the formula III to chlorosulfonation with N-chlorosuccinimide NCS, formicacid or acetic acid, water and an organic solvent, thereby obtaining the 2-(2,2-difluoroethoxy)-6-(trifluoromethyl)benzenesulfonyl chloride. According to the synthesis method disclosed by the invention, the cost is low, reaction steps are few, the operation is convenient, and the yield of a target product can be stabilized to 83% or more.
- -
-
-
- Preparation method of 2-(2,2-difluoroethyoxyl)-6-trifluoromethyl benzenesulfonyl chloride
-
The invention relates to the technical field of synthesis of pesticides and particularly relates to a preparation method of 2-(2,2-difluoroethyoxyl)-6-trifluoromethyl benzenesulfonyl chloride. The preparation method comprises the following steps: reacting m-trifluoromethylphenol with 3,4-dihydropyran to obtain a compound expressed as a formula (I), reacting the compound expressed as the formula (I) with n-butyl lithium and sulphur to obtain a compound expressed as a formula (II), reacting the compound expressed as the formula (II) under the action of an inorganic acid catalyst to obtain a compound expressed as a formula (III), reacting an alcoholic solution of elementary iodine or an alcoholic solution of iodide with the compound expressed as the formula (III) to obtain a compound expressed as a formula (IV), then reacting the compound expressed as the formula (IV) with carbonate and p-toluenesulfonate difluoroethanol sulfonate to obtain a compound expressed as a formula (V), and reacting the compound expressed as the formula (V) with a chlorination reagent and an oxidation reagent to obtain a final product. Through the preparation method, the generation of foul odor in the conventional synthesis process is avoided; chlorine gas with high risk is not used as the chlorination reagent; the safety in production is greatly improved.
- -
-
Paragraph 0067; 0074; 0082; 0089
(2018/10/02)
-
- 2 - phenoxy four hydrogens fu ([...]) five fluorine sulphur grass amine[...] derivatives and their application in the synthesis of
-
The invention discloses 2-phenoxyl tetrahydrofuran (tetrahydropyrane) derivatives and the application thereof in synthesis of penoxsulam, and belongs to the field of pesticide synthesis. A new intermediate of a penoxsulam pesticide is synthesized by the derivatives of the design of the invention. A high-toxicity raw material is not required to be used in the preparation of the intermediate; a product is convenient to purify and high in yield; a synthesizing process is environment-friendly; the synthesis cost is low. The penoxsulam pesticide can be prepared conveniently by utilizing the intermediate; the intermediate has a good application prospect. The series of derivatives are easy and convenient to synthesize; compared with the reported penoxsulam intermediate, a low-boiling-point raw material with high toxicity, namely, chloromethyl methyl ether, is not required to be used in the synthesizing process; the safety of the synthesizing process is improved; the derivatives are favorable to industrialized production and application.
- -
-
Paragraph 0104; 0107
(2017/06/30)
-
- Method for preparation of 2-(2,2-difluoroethoxy)-6-(trifluoromethyl)benzene-1-sulfonyl chloride
-
The invention belongs to the field of organic synthesis, and discloses a new route and new method for preparation of an agricultural herbicide penoxsulam intermediate, and in particular, relates to a method for preparation of 2-(2,2-difluoroethoxy)-6-(trifluoromethyl)benzene-1-sulfonyl chloride. The method comprises the steps: in the presence of a solvent, with potassium carbonate as an acid binding agent, under the action of a thiolation reagent n-propylmercapatan, and at the temperature of 15-80 DEG C, carrying out a reaction of 2-chloro-1-nitro-3-(trifluoromethyl)-benzoic acid with the reaction time of 1-8 hours; in the presence of the solvent, carrying out a reaction of the obtained substance with tetrabutylammonium fluoride for 1-6 hours at the temperature of 75-120 DEG C; in the presence of the solvent, carrying out a reaction of the obtained 1-fluoro-2-propylthio-3-trifluoromethyl benzene with 2,2-difluoroethanol and sodium hydride for 1-15 hours at the temperature of 15-70 DEG C; and carrying out a reaction of the obtained 1-(2,2-difluoroethoxy)-2-propylthio-3-trifluoromethyl benzene with chlorine gas for 1-6 hours at the temperature of 15-60 DEG C. The method has the advantages of simple process, mild reaction, and relatively high product content and yield.
- -
-
Paragraph 0033; 0034
(2016/10/31)
-
- Synthesis, crystal structure and herbicidal activity of a series of [1,2,4]triazolo[1,5-a]pyrimidine-2-sulfonamide compounds
-
With the aim of obtaining efficient, safe and environmentally friendly green herbicide, a series of [1,2,4]triazolo[1,5-a]pyrimidine-2-sulfonamide compounds (8a-8f) were synthesized by reacting 2-amino-5,7-(bis-substituted)- 1,2,4-triazolo[1,5-a]pyrimidine (4a and 4b) with 2-substituted-6-trifluoromethyl-benzenesulfonyl chloride (7a-7c). And their structures were characterized by H-NMR, C-NMR, HRMS, FTIR, single-crystal X-ray diffraction, elemental analysis. Moreover, their herbicidal activities against six species of weeds were evaluated. Three target compounds such as 8a, 8c and 8e, exhibited significant postemergence herbicidal activity against some common dicotyledons and monocotyledons under different concentrations. The structure and activity relationship is discussed based on the herbicidal performances of the compounds with different substituents. The investigation results indicated that the above structures could serve as lead compounds for the development of new herbicides.
- Ma, Yi-Chao,Yu, Ying-Hui,Hou, Guang-Feng,Huang, Ji-Han,Gao, Jin-Sheng
-
p. 829 - 843
(2016/07/06)
-
- A 6 - substituted -2 - trifluoromethylbenzene sulfonyl chloride method for the preparation of
-
The invention relates to a preparation method of 6-substituted-2-trifluoromethylbenzenesulfonyl chloride as a key intermediate of sulfonamide or sulfonylurea herbicides. The method comprises the following steps: 6-fluoro-2-trifluoromethylbenzenethioether is formed through fluorine displacement and sulfenyl group substitution of a raw material 2,3-dichlorobenzotrifluoride, chlorine oxidative chloridization or substitution of 6-fluoro-2-trifluoromethylbenzenethioether is carried out, and then chlorine oxidative chloridization of the finally obtained material is carried out to obtain the above product. The method has the advantages of easily available raw materials, simple process, high yield and low cost.
- -
-
-
- Preparation method of 2-(2',2'-difluoroethoxy)-6-(trifluoromethyl)benzene-1-sulfonyl chloride
-
The invention discloses a preparation method of 2-(2',2'-difluoroethoxy)-6-(trifluoromethyl)benzene-1-sulfonyl chloride. The preparation method comprises following steps: (1) a sulfonyl chloride or a sulfonic anhydride is added into an organic solvent containing 2,2-difluoroethanol and an alkali, and a compound I is obtained via complete reaction, wherein the sulfonyl chloride is selected from alkyl sulfonyl chloride or benzene sulfonyl chloride, and the sulfonic anhydride is selected from alkyl sulfonic anhydride or benzene sulfonic anhydride; (2) m-trifluoromethylphenol, the compound I, and an alkali are added into an organic solvent, an obtained mixture is heated and stirred, and a compound II is obtained via complete reaction; and (3) an accelerant and the compound II are added into an organic solvent, a strong alkali is added, the sulfonyl chloride is added into an obtained reaction solution, and 2-(2',2'-difluoroethoxy)-6-(trifluoromethyl)benzene-1-sulfonyl chloride is obtained via complete reaction and purifying. The preparation method is simple, is high in efficiency, is safe and reliable, and is capable of increasing synthesis efficiency of penoxsulam greatly; and operation is simple and convenient.
- -
-
Paragraph 0039; 0040
(2016/10/08)
-
- Penoxsulam-Structure-activity relationships of triazolopyrimidine sulfonamides
-
The discovery of the sulfonamide herbicides, which inhibit the enzyme acetolactate synthase (ALS), has resulted in many investigations to exploit their herbicidal activity. One area which proved particularly productive was the N-aryltriazolo[1,5-c]pyrimidine sulfonamides, providing three commercial herbicides, cloransulam-methyl, diclosulam and florasulam. Additional structure-activity investigations by reversing the sulfonamide linkage resulted in the discovery of triazolopyrimidine sulfonamides with cereal crop selectivity and high levels of grass and broadleaf weed control. Research efforts to exploit these high levels of weed activity ultimately led to the discovery of penoxsulam, a new herbicide developed for grass, sedge and broadleaf weed control in rice. Synthetic efforts and structure-activity relationships leading to the discovery of penoxsulam will be discussed.
- Johnson, Timothy C.,Martin, Timothy P.,Mann, Richard K.,Pobanz, Mark A.
-
experimental part
p. 4230 - 4240
(2009/10/02)
-