Process for preparing fluoxastrobin

• US 9,670,171 B2
• Filed: 10/23/2015
• Issued: 06/06/2017
• Est. Priority Date: 07/08/2013
• Status: Active Grant

• Current Assignee: Arysta Lifescience (Element Solutions Inc)
• Original Assignee: Arysta Lifescience (Element Solutions Inc)
• Inventors: Hindupur, Rama Mohan, Mane, Avinash Sheshrao, Balakrishnan, Sankar, Pawar, Jivan Dhanraj, Maddani, Mahagundappa Rachappa, Wadhwa, Sandeep, Prasad, Vic
• Primary Examiner(s): Habte, Kahsay
• Application Number:
  US14/921,657
• Publication Number:
  US 20160237047A1
• Time in Patent Office: 592 Days
• Field of Search: 544 65
• CPC Class Codes: C07D 273/00 Heterocyclic compounds containing rings having nitrogen and oxygen atoms as the only ring hetero atoms, not provided for by groups C07D261/00 - C07D271/00
• CPC Class Codes: C07D 273/01 having one nitrogen atom
• CPC Class Codes: C07D 413/12 linked by a chain containing hetero atoms as chain links

Abstract

A process for preparing (E)-(5,6-dihydro-1,4,2-dioxazin-3-yl)(2-hydroxyphenyl)methanone O-methyl oxime (13) or (Z)-(5,6-dihydro-1,4,2-dioxazin-3-yl)(2-hydroxyphenyl)methanone O-methyl oxime (15) which includes: (a) reacting

• • compound (10) with an alkyl nitrite in the presence of an acid to form compound (11A) or reacting compound (10) with an alkyl nitrite in the presence of a base to form compound (11B); (b) reacting compound (11A) with 2-haloethanol to form compound (12A) or reacting compound (11B) with 2-haloethanol to form compound (12B); and (c) reacting compound (12A) with a base to form compound (13) or reacting compound (12B) with a base to form compound (15).

Claims

1. A process for preparing (E)-(5,6-dihydro-1,4,2-dioxazin-3-yl)(2-hydroxyphenyl)methanone O-methyl oxime (13)

3. The process of claim 1, wherein the alkyl nitrite is n-butyl nitrite or t-butyl nitrite.

4. The process of claim 1, wherein the acid is hydrochloric acid, sulfuric acid, methanesulfonic acid, or phosphoric acid, or a combination thereof.

5. The process of claim 1, wherein a content of the (3E)-2,3-benzofuran-dione O³-methyl dioxime (11A) in a mixture of (3E)- and (3Z)-isomers is from 90% to 94%.

6. The process of claim 1 wherein the base reacted with (12A) is metal hydroxide.

7. The process of claim 3, wherein the base is lithium hydroxide, sodium hydroxide, potassium hydroxide, or a combination thereof.

2. A process of preparing (Z)-(5,6-dihydro-1,4,2-dioxazin-3-yl)(2-hydroxyphenyl)methanone O-methyl oxime (15)

8. The process of claim 2, wherein the base used to react the benzofuran-3(2H)-one O-methyl oxime (10) with an alkyl nitrite is a metal hydroxide, a metal hydride, a metal alkoxide, or a combination of the foregoing.

9. The process of claim 2, wherein the alkyl nitrite is n-butyl nitrite or t-butyl nitrite.

10. The process of claim 2, wherein the base in the reacting benzofuran-3(2H)-one O-methyl oxime (10) with an alkyl nitrite comprises a metal hydroxide, a metal hydride, and a metal alkoxide.

11. The process of claim 2, wherein a content of the (3Z)-2,3-benzofuran-dione O³-methyl dioxime (11B) in a mixture of (3E)- and (3Z)-isomers is 94% to 98%.

12. The process of claim 2, wherein the reaction of (3Z)-2,3-benzofuran-dione O³-methyl dioxime (11B) with 2-haloethanol to form (Z)-benzofuran-2,3-dione O²-(2-hydroxyethyl) O³-methyl dioxime (12B) may be carried out at a temperature of about 20°

C. to about 100°

C.

13. The process of claim 2, wherein the base reacted with (2)-benzofuran-2,3-dione O²-(2-hydroxyethyl) O³-methyl dioxime (12B) to form (Z)-(5,6-dihydro-1,4,2-dioxazin-3-yl)(2-hydroxyphenyl)methanone O-methyl oxime (15), is a metal hydroxide.

14. The process of claim 12, wherein the base is lithium hydroxide, sodium hydroxide, potassium hydroxide, or a combination thereof.