| abstract |
The present invention provides a process for the preparation of polymers comprising at least units of formula (1), the process comprising (v) treating with an S-donor reagent wherein Y 2 is I, Br, Cl or O-S(O) 2 CF 3 A compound of formula (5) to obtain a compound of formula (4) wherein Y 2 is as defined for a compound of formula (5), a process for preparing a compound of formula (4) and a compound of formula (4). |