PREPARATION OF DIFLUOROPYRIDINE COMPOUNDS

摘要

Alpha, beta- and beta, gamma-difluoropyridine compounds are prepared by contacting a beta-halo- alpha- or gammafluoropyridine compound or suitable precursor thereof with an effective amount of KF in a polar aprotic solvent (diluent) at an elevated temperature under substantially anhydrous conditions with removal of the difluoropyridine products essentially as they are formed. The starting material may optionally be added as the reaction proceeds to minimize decomposition. The reaction is also optionally conducted in the presence of an acid scavenger and/or a crown ether or other phase-transfer catalyst.