Patent ID: 8927731
Filing Date: 2015-01-06
Classification: C07D

Abstract:
1. A process for the preparation of a 4-amino-5-fluoro-3-halo-6-(substituted)-picolinate of the Formula I wherein W represents Cl, Br or I; R represents C R which comprises the following steps: a) fluorinating the a 4,5,6-trichloropicolinate of Formula A wherein R with a source of fluoride ion to produce a 4,5,6-trifluoropicolinate of Formula B wherein R b) aminating 4,5,6-trifluoropicolinate of Formula B with ammonia to produce a 4-amino-5,6-difluoropicolinate of Formula C wherein R c) exchanging the fluoro substituent in the 6-position of the 4-amino-5,6-difluoro picolinate of Formula C with an iodo, bromo or chloro substituent by treating with an iodide, bromide or chloride source to produce a 4-amino-5-fluoro-6-halopicolinate of Formula D wherein X represents Cl, Br or I, and R d) halogenating the 4-amino-5-fluoro-6-halopicolinate of Formula D with a halogen source to produce a 4-amino-3,6-dihalo-5-fluoropicolinate of Formula E wherein W and X independently represent Cl, Br or I, and R e) coupling the 4-amino-3,6-dihalo-5-fluoropicolinate of Formula E with an aryl, alkyl or alkenyl metal compound of the Formula F wherein R is as previously defined and Met represents Zn-halide, Zn—R, tri-(C