Preparation of halogen analogs of picloram

US12017993B2 · kind B2 · utility

Assignee

• CORTEVA AGRISCIENCE LLC · US

Inventors

• Jayachandran Devaraj · Zionsville, US
• Nugzar Ghavtadze · Montréal, CA
• Nicholas M. Irvine · Westfield, US
• Jeremy Kister · Carmel, US
• Melissa Lee · Indianapolis, US
• Ronald B. Leng · Midland, US
• Rongrong [Mandy] Lin · Edmonton, CA
• Rong Ling · Edmonton, CA
• Noormohamed M. Niyaz · Indianapolis, US
• Abraham D. Schuitman · Midland, US
• Aaron A. Shinkle · Brownsburg, US
• Siyu Tu · Midland, US
• Gregory T. Whiteker · Carmel, US
• Chunming Zhang · Zionsville, US

Key dates

• Filing date: Jun 23, 2022
• Grant date: Jun 25, 2024
• Expiry date: Jul 17, 2042

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07D213/79
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

Methods for preparing 5-fluoro-6-(bromo or chloro)picloram analogs, or derivatives thereof, from picloram acid, picloram ester, or the nitrile analog of picloram are provided. The methods include chemical process steps that: (1) introduce a phthaloyl group onto the 4-amino substituent of picloram acid, picloram ester, or the nitrile analog of picloram, (2) add 2 fluorine atoms at the 5,6-positions of the pyridine ring using halex fluorination chemistry, (3) remove the phthaloyl group, hydrolyze the ester or nitrile substituent, and add chlorine or bromine to the 6-position by treatment with an acid and water, and finally, (4) esterify the 5-fluoro-6-(bromo or chloro)picloram acid produced in step (3) to a 5-fluoro-6-(bromo or chloro)picloram ester.