公开(公告)号：US20220371997A1

公开(公告)日：2022-11-24

申请号：US17808368

申请日：2022-06-23

Applicant: CORTEVA AGRISCIENCE LLC

Inventor： JAYACHANDRAN DEVARAJ ,  NUGZAR GHAVTADZE ,  NICHOLAS M. IRVINE ,  JEREMY KISTER ,  MELISSA LEE ,  RONALD B. LENG ,  RONGRONG [MANDY] LIN ,  RONG LING ,  NOORMOHAMED M. NIYAZ ,  ABRAHAM D. SCHUITMAN ,  AARON A. SHINKLE ,  SIYU TU ,  GREGORY T. WHITEKER ,  CHUNMING ZHANG

IPC: C07D213/803

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.