Patent ID: 7259176

Claim:
A process for the preparation of compounds of formula (I) comprising reacting a compound of formula (II) with a compound of formula (III) to yield the compound of formula (I), wherein R 1 is aryl or heteroaryl, R 2 is lower-alkyl, R 3 is COOR 7 , R 4 is COOR 8 , R 5 and R 6 independently from each other are lower-alkyl, fluoro-lower-alkyl, aryl or —CH 2 -aryl, R 7 and R 8 independently from each other are lower-alkyl, cycloalkyl, aryl or —CH 2 -aryl, or R 3 and R 5 together are —CH═CH—CH═CH— to form a benzene ring together with the carbon atoms to which they are attached and R 4 and R 6 together are —CH═CH—CH═CH— to form a benzene ring together with the carbon atoms to which they are attached.