Sulfuric Acid → Methyl 4-amino-5-fluoro-3-chloro-6-(4-chlorophenyl)picolinate

Participants

Reaction Steps

In a typical reaction accomplishing both chlorination and deprotection, methyl 4-(4-methoxyphenylamino)-5-fluoro-6-(4-chlorophenyl)picolinate is reacted with about two equivalents of 1,3-dichloro-5,5-dimethylimidazolidine-2,4-dione in the presence of a 1 M (molar) solution of sulfuric acid in a mixture of acetonitrile/water. The mixture is heated at reflux until the reaction is complete. The mixture is added to methylene chloride and the organic layer is separated, washed with brine and dried. The solvent is evaporated to provide crude methyl 4-amino-5-fluoro-3-chloro-6-(4-chlorophenyl)picolinate.

Provenance & Evidence