| abstract |
A process for the preparation of a compound of formula (I) n ncomprising the steps: n n(a) reacting a compound of formula (II) n n wherein L and L′ are suitable leaving groups, with a compound of formula (III) n nUNH 2 (III) n n to prepare a compound of formula (IV) n n and subsequently (b) substituting the group R 1 by replacement of the leaving group L′. |