| abstract |
The present invention relates to a process for the preparation of compounds of formula (I) wherein the substituents are as defined in claim 1, by reaction of a compound of formula (II) wherein R3 is C1-C8alkyl or C3-C6cycloalkyl and R4 and R05 are as defined for formula (I), with a compound of formula (III) wherein R, R1, R2 and X1, are as defined for formula (I) in claim 1, in an inert solvent in the presence of a proton source. |