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CN-122003398-A - Method of

CN122003398ACN 122003398 ACN122003398 ACN 122003398ACN-122003398-A

Abstract

A process for preparing a compound of formula (I) wherein R 1 is selected from one or more of alkyl, substituted alkyl, haloalkyl, cyanoalkyl, alkoxy, halo, haloalkoxy, amino, aminoalkyl, alkylsulfonyl, arylsulfonyl, alkylsulfanyl and hydroxy, wherein n is selected from 1, 2 or 3, comprising reacting a compound of formula (II) with 2-halo heptafluoropropane in the presence of sodium dithionite (Na 2 S 2 O 4 ) and an aqueous buffer, wherein the aqueous buffer comprises an acid and a base.

Inventors

  • I. Kretus

Assignees

  • 先正达农作物保护股份公司

Dates

Publication Date
20260508
Application Date
20241004
Priority Date
20231011

Claims (15)

  1. 1. A process for preparing a compound having formula I: I is a kind of Wherein R 1 is selected from one or more of alkyl, substituted alkyl, haloalkyl, cyanoalkyl, alkoxy, halogen, haloalkoxy, amino, aminoalkyl, alkylsulfonyl, arylsulfonyl, alkylsulfanyl and hydroxy, wherein n is selected from 1, 2 or 3, The method comprises reacting a compound having formula II: II (II) With 2-halogenated heptafluoropropane, In the presence of sodium dithionite (Na 2 S 2 O 4 ) and an aqueous buffer, Wherein the aqueous buffer comprises an acid and a base.
  2. 2. The method of claim 1, wherein R 1 is selected from one or more of C 1-3 alkyl, C 1-3 haloalkyl, C 1-3 alkoxy, chloro, fluoro, iodo, C 1-3 haloalkoxy, amino C 1-3 alkyl, arylsulfonyl, C 1-3 alkylsulfanyl, and hydroxy.
  3. 3. The process according to claim 1 or 2, wherein the 2-halogenated heptafluoropropane is 2-iodoheptafluoropropane.
  4. 4. The process according to any of the preceding claims, wherein the process is carried out at a pH value of 3 to 5, preferably at a pH value of 4 to 4.5.
  5. 5. A method according to any one of the preceding claims, wherein the acid is a weak acid, preferably selected from citric acid, acetic acid, lactic acid, methyl maleic acid, tartaric acid, phosphoric acid and/or formic acid.
  6. 6. The method of any one of the preceding claims, wherein the base is selected from sodium hydroxide, potassium hydroxide, lithium hydroxide, ammonium acetate, ammonium formate.
  7. 7. The process according to any one of the preceding claims, wherein the ratio of 2-halogenated heptafluoropropane to formula II is from 0.8:1 to 2:1.
  8. 8. The process according to any of the preceding claims, wherein the process is carried out in the presence of an alcohol solvent, an ether solvent or an ester solvent, preferably in the presence of an ester solvent.
  9. 9. The method of any one of the preceding claims, further comprising adding sodium carbonate (Na 2 CO 3 ).
  10. 10. A method according to any one of the preceding claims, further comprising a Phase Transfer Catalyst (PTC).
  11. 11. The process according to any of the preceding claims, wherein the reaction is carried out at a reaction temperature of 25 ℃ to 50 ℃, preferably at a reaction temperature of 30 ℃ to 40 ℃.
  12. 12. The process of claim 11 wherein the compound of formula II and 2-halogenated heptafluoropropane are combined in a reaction vessel; heating the vessel to the reaction temperature, and The sodium dithionite solution is added in a metered manner at such a rate that the reaction temperature is not exceeded.
  13. 13. The process of any one of the preceding claims, further comprising recycling any unreacted compound of formula II back into the reaction chamber.
  14. 14. A process for preparing an agrochemical comprising any of the preceding claims.
  15. 15. A compound of formula I, prepared by a process according to any one of claims 1 to 14.

Description

Method of The present invention relates to a novel process for the preparation of perfluoroaryl compounds and to the use of said perfluoroaryl compounds as intermediates in the preparation of agrochemicals. The carbon-carbon bond formation reactions of perfluoroaryl compounds in the presence of sodium dithionate are known in the art, see, for example, 'Hernandez et al, the Journal of Organic Chemistry [ journal of organic chemistry ], 2021 86 (15), 10903-10913'. However, such reactions are time consuming, their results are not consistent, and scale up to commercially viable processes is also extremely difficult. In particular, the methods described in the art are associated with initiation periods, pH changes (especially when the process is initiated in the reaction chamber) and excessive reduction of fluorine-containing reagents to the corresponding environmentally persistent hydrofluorocompounds. The present invention addresses at least these technical challenges and accordingly provides a process for preparing a compound having formula I: I is a kind of Wherein R 1 is selected from one or more of alkyl, substituted alkyl, haloalkyl, cyanoalkyl, alkoxy, halogen, haloalkoxy, amino, aminoalkyl, alkylsulfonyl, arylsulfonyl, alkylsulfanyl and hydroxy, wherein n is selected from 1, 2 or 3, The method comprises reacting a compound having formula II: II (II) With 2-halogenated heptafluoropropane, In the presence of sodium dithionite (Na 2S2O4) and an aqueous buffer, Wherein the aqueous buffer comprises an acid and a base. Unexpectedly, it was found that this method is robust, inexpensive, non-toxic, reproducible and environmentally friendly. The high water solubility of the buffer system also improves the degree of product isolation. Preferably, R 1 is selected from one or more of C 1-3 alkyl, C 1-3 haloalkyl, C 1-3 alkoxy, chloro, fluoro, iodo, C 1-3 haloalkoxy, amino, aminoC 1-3 alkyl, arylsulfonyl, C 1-3 alkylsulfanyl, and hydroxy. Preferably, when 'n' is greater than 1, R 1 is selected from one or more of alkyl, substituted alkyl, haloalkyl, cyanoalkyl, alkoxy, halogen, haloalkoxy, aminoalkyl, alkylsulfonyl, arylsulfonyl, alkylsulfanyl, and hydroxy. More preferably, when 'n' is greater than 1, R 1 is selected from one or more of C 1-3 alkyl, C 1-3 haloalkyl, C 1-3 alkoxy, chlorine, fluorine, iodine, C 1-3 haloalkoxy, amino C 1-3 alkyl, arylsulfonyl, C 1-3 alkylsulfanyl, and hydroxy. As used herein, the term "halogen" refers to fluorine (fluoro/fluoro), chlorine (chlorine/chloro), bromine (bromine/bromo) or iodine (iodine/iodo). As used herein, the term "hydroxyl" or "hydroxyl" means an-OH group. As used herein, the term "mercapto" or "mercapto" means a-SH group. As used herein, the term "cyano" means a —cn group. As used herein, amino means an-NH 2 group. As used herein, acyl means a-C (O) CH3 group. As used herein, formyl means a-C (O) H group. As used herein, oxo means an =o group (e.g., as in a carbonyl (c=o) group). As used herein, the term "alkyl" refers to a straight or branched hydrocarbon chain group consisting of only carbon and hydrogen atoms, containing no unsaturation, and attached to the rest of the molecule by a single bond. The term "C1-3 alkyl" should be construed accordingly. Examples of C1-6 alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, and isomers thereof, e.g., isopropyl. An "alkylene" group refers to the corresponding definition of alkyl, except that such group is attached to the rest of the molecule by two single bonds. The term "C1-2 alkylene" should be interpreted accordingly. Examples of C1-3 alkylene groups include, but are not limited to, -CH2-, -CH2CH2-, and- (CH 2) 3-. As used herein, the term "haloalkyl" refers to an alkyl group as generally defined above substituted with one or more halogen atoms, which may be the same or different. C1-3 haloalkyl is to be construed accordingly. Examples of C1-3 haloalkyl include, but are not limited to, fluoromethyl, fluoroethyl, difluoromethyl, trifluoromethyl and 2, 2-trifluoroethyl. As used herein, the term "cyanoalkyl" refers to an alkyl group as generally defined above substituted with one or more cyano groups. Cyano C1-3 alkyl should be construed accordingly. Examples of cyanoC 1-3 alkyl groups include, but are not limited to, cyanomethyl. As used herein, the term "alkoxy" refers to a group having the formula-ORa, wherein Ra is an alkyl group as generally defined above. C1-3 alkoxy is to be construed accordingly. Examples of C1-3 alkoxy groups include, but are not limited to, methoxy, ethoxy, propoxy, and isopropoxy. As used herein, the term "haloalkoxy" refers to an alkoxy group as defined above substituted with one or more identical or different halogen atoms. C1-3 haloalkoxy should be construed accordingly. Examples of C1-3 haloalkoxy groups include, but are not limited to, fluoromethoxy, difluoromethoxy, fluoroethoxy, trifluoromethoxy, and trifluoroethoxy. As used herein, the term "aminoalkyl" refers to a gro