Synthesis of a hydrocarbylvinylphosphonic acid hydrocarbyl ester

The known ester compounds of the type encompassed by the terminology used in the title, such as those of 1-phenylvinylphosphonic acid, are useful as intermediates for further chemical synthesis of, for example, plasticizers, flame retardants, and the like. Such compounds are also useful as comonomers, in minor amount, with a predominant amount of other vinylic monomers to impart flame retardancy and to alter the surface characteristics of the resulting polymer product. Various disclosures exist in regard to the process of formation of such compounds. A process for the synthesis of a hydrocarbylvinyl-1-phosphonic acid hydrocarbyl ester, such as a 1-phenylvinylphosphonic acid dialkyl ester, which utilizes: (a) the base catalyzed addition (preferably using a nonnucleophilic strong organic base) of a hydrocarbyl phosphite, such as a dialkyl phosphite containing no more than about eight carbon atoms in either of its alkyl groups, to an aldehyde or methyl ketone, such as a phenyl ketone, as exemplified by acetophenone, to form a hydrocarbyl 1-hydroxy-1-hydrocarbylphosphonate, such as a dialkyl 1-hydroxy-1-phenylalkylphosphonate compound; (b) the acid-catalyzed esterification (preferably acetylation) of the compound from (a) with an acid anhydride to form an acylated intermediate; and (c) the removal of carboxylic acid (preferably at a temperature of from about 50° C. to about 215° C. under reduced or atmospheric pressure) from the intermediate from (b) to form the desired hydrocarbylvinylphosphonic acid hydrocarbyl ester, such as a 1-phenylvinylphosphonic acid dialkyl ester.