Patent ID: 6169183
Filing Date: 2001-01-02
Classification: C07D

Abstract:
A process for preparing a pyridinecarboxylic ester of formula: ##STR6## wherein R.sup.1 is a fluorinated C.sub.1-6 -alkyl group, R.sup.2 is a C.sub.1-4 -alkyl group and X is chlorine or bromine, consisting essentially of reacting a 2,3-dihalopyridine of formula: ##STR7## wherein R.sup.1 and X are each as defined above, with carbon monoxide and a C.sub.1-4 -alkanol in the presence of a weak base and in the presence of a complex of palladium with a bis(diphenylphosphine) of formula: ##STR8## wherein Q is a C.sub.3-6 -alkanediyl group or a 1,1'-ferrocenediyl group having optionally C.sub.1-4 -alkyl- or aryl-substituted cyclopentadienyl groups and R.sup.3 to R.sup.6, independently of one another, are each hydrogen, C.sub.1-4 -alkyl, C.sub.1-4 -alkoxy, fluoromethyl, fluorine, aryl, phenoxy, nitrile or dialkylamino, the weak base being selected from the group consisting of an alkali metal acetate, an alkaline earth metal acetate, an alkali metal hydrogen carbonate, alkaline earth metal hydrogen carbonate, an alkali metal hydrogen phosphate, and an alkaline earth metal hydrogen phosphate, the reaction is stopped as soon as maximum concentration of the pyridinecarboxylic ester of formula I is achieved.