Patent ID: 8334401

Claim:
A process for the production of polymerizable monomers corresponding to formula (I): in which the substituent R 1 is hydrogen or a C 1-4 alkyl group, R 2 to R 4 independently represent hydrogen or an aliphatic, cycloaliphatic or aromatic moiety, X is a group —(CH 2 ) n and n is the number 0 or 1, Y is a group —(CHR 5 ) m , and m is the number 0, 1 or 2, and R 5 is hydrogen or an OH group, the process comprising the steps of: (a). hydrolyzing a compound corresponding to formula (II): in which the substituents R 1 , R 2 to R 4 , X and Y are as defined above and the substituents R 6 and R 7 independently represent hydrogen or an aliphatic group, in aqueous medium and in the presence of an acid dissolved in the aqueous medium to form a mixture, the hydrolysis being accompanied by elimination of a compound (III): in which R 6 and R 7 are as defined above, and (b) contacting said mixture with a weak base to neutralize the acid present in the mixture, said base having a pK b value above 0.18 and being present in heterogeneous form.