1885-09-2Relevant academic research and scientific papers
Perfluoro- and Polyfluorosulfonic Acids. 21. Synthesis of Difluoromethyl Esters Using Fluorosulfonyldifluoroacetic Acid as a Difluorocarbene Precursor
Chen, Qing-Yun,Wu, Sheng-Wen
, p. 3023 - 3027 (2007/10/02)
Difluoromethyl alkanoates 5 and fluorinated and nonfluorinated alkanesulfonates 9 were synthesized in moderate yields by the reaction of alkali metal salts of acids with fluorosulfonyldifluoroacetic acid (3) in acetonitrile under mild conditions.The presumed intermediate anion FO2SCF2CO2- generates CF2: by elimination of SO2, CO2, and F-.The esters are formed by insertion of CF2: into the O-H of the acid, whereas HCF3 is formed by the competing capture of F-.Organic acids can be used indirectly in the reaction in the presence of inorganic salts such as Na2SO4 and KCl, with comparable yields of difluoromethyl esters.
