Patent ID: 8207354

Claim:
A process for preparing an alkyl 2-alkoxymethylene-4,4-difluoro-3-oxobutyrate of the formula (VI) where R is methyl or ethyl, from crude reaction mixtures of alkyl 4,4-difluoroacetoacetate (I) which comprises a) initially charging two of the following components (II), (III) and (IV) where M is a lithium, sodium or potassium ion, and and reacting this mixture with the third component to form an enolate of the formula (V) b) adding an acid to the reaction mixture to release the corresponding alkyl 4,4-difluoroacetoacetate of formula (I) from the enolate (V), c) removing the salt formed from cation M and the acid anion as a solid and d) converting (I), without isolation from the crude reaction mixture, to the alkyl 2-alkoxymethylene-4,4-difluoro-3-oxobutyrate of the formula (VI).