Patent ID: 9067890
Filing Date: 2015-06-30
Classification: C07D

Abstract:
1. A process for the preparation of a 4-amino-3-chloro-5-fluoro-6-(substituted)picolinate of the Formula I wherein R represents C R which comprises the following steps: a) fluorinating 3,4,5,6-tetrachloropicolinonitrile (Formula A) with a source of fluoride ion to produce 3-chloro-4,5,6-trifluoropicolinonitrile (Formula B) b) aminating 3-chloro-4,5,6-trifluoro-2-picolinonitrile (Formula B) with ammonia to produce 4-amino-3-chloro-5,6-difluoropicolinonitrile (Formula C) c) exchanging the fluoro substituent in the 6-position of 4-amino-3-chloro-5,6-difluoropicolinonitrile (Formula C) with hydrogen bromide (HBr), hydrogen chloride (HC1) or hydrogen iodide (HI) and hydrolyzing the nitrile to produce a 4-amino-3-chloro-5-fluoro-6-halopicolinamide of Formula D wherein L is Br, Cl or I; d) esterifying the 4-amino-3-chloro-5-fluoro-6-halopicolinamide of Formula D with a strong acid and an alcohol (R wherein L and R e) coupling the 4-amino-3-chloro-5-fluoro-6-halopicolinate 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