US Patent 4,330,486
United States Patent and Trademark Office
University of Iowa Research Foundation (Iowa City, IA, US)
Fluorine-containing phosphonates and phosphonic acids are described. The method of preparation is a reaction of trialkylphosphites with dihalodifluoromethanes or a reaction of the salts of dialkylphosphites with halodifluoromethylphosphonates. The corresponding phosphonic acids are prepared by hydrolysis of the phosphonates.
Burton, Donald J. and Flynn, Richard M. Bis(phosphonic acid) difluoromethane. US Patent 4,330,486 filed April 28, 1980 and issued May 18, 1982. https://ir.uiowa.edu/patents/28