Hydrolyses of 2- and 4-Fluoro N-Heterocycles. 2. Nucleophilic Catalysis by Buffer Bases in the Hydrolysis of 2-Fluoro-1-methylpyridinium Iodide

Article abstract of DOI:10.1021/jo00232a025

Pseudo-first-order rate constants are reported for hydrolysis of 2-fluoro-1-methylpyridinium iodide (1) in carboxylate buffers.The reaction is catalyzed by the carboxylase bases, with a Brensted slope of 0.66.Hydrolyses in 99percent 18O-labeled water with 0.04 M unlabeled acetate and complementary hydrolyses in unlabeled water with 90percent 18O-labeled acetate indicate that 85-95percent of the oxygen in product 2 is derived from the acetate rather than from water.The results are consistent with nucleophilic catalysis by acetate (and presumably by the other carboxylate bases) rather than general base catalysis.