Reactions of Phosphodiester Anions with Phosgene

Article abstract of DOI:10.1021/jo00154a020

The mechanisms of reactions of phosgene with the N-methylpyridinium salts of diphenyl phosphate and 1,2-dimethylethenylene phosphate (or 4,5-dimethyl-2-oxido-2-oxo-1,3,2-dioxaphosphole) have been studied by 31P NMR spectrometry in dichloromethane at various temperatures and molar ratios of reactants.The products are mixtures of pyrophosphates and phosphorochloridates in proportions that vary with the structure of the phosphodiester and the experimental conditions.The reactions have also been carried out in benzene suspension.The conditions can be adjusted to give exclusively and in high yields (over 85percent) either bis(1,2-dimethylethenylene)pyrophosphate or 1,2-dimethylethenylene phosphorochloridate (or 2-chloro-4,5-dimethyl-2-oxo-1,3,2-dioxaphosphole).These cyclic enediol phosphoryl derivatives are excellent reagents for the synthesis of complex biological phosphodiesters.