abstract |
A process for preparing a compound of formula I, comprising a reaction of a compound of formula II with a compound of formula III: (I) [In the meal, R 1 , R 2 , R 3 , R 4 , R 5 and R 6 have the meanings defined in claim 1; [Formula II] [In the meal, R 1 , R 2 , R 3 , R 4 have the meanings defined above; [Formula III] [In the meal, R 5 , R 6 have the meanings defined above. |