Patent ID: 8133997

Claim:
A compound of formula (II) where the two monomeric units are linked either via R 3 or via R 4 ; the ring A is a six-membered heteroaromatic ring of structure A1 where the ring A1 is unsubstituted, C 1 -C 4 -alkyl or phenyl substituted fused with a benzene ring or a combination thereof, one of R 3 and R 4 is an unsubstituted phenylene radical or a phenylene radical substituted by one or more of alkyl-, alkoxy- or halogen-substitutions, the other one of R 3 and R 4 is C 1 -C 4 -alkyl, C 5 -C 6 cycloalkyl, an unsubstituted phenyl, a phenyl substituted by one or more of alkyl-, alkoxy-, nitro-, phenyl-, alkoxycarbonyl-, dialkylamino-, dialkylaminocarbonyl-, alkylaminocarbonyl-, aminocarbonyl- or halogen-substitutions, benzyl, benzanilide, C 5 -C 6 -cycloalky or naphthyl; or where the NR 4 group combines with the A ring to form a 6-membered heterocycle optionally fused with a benzene ring, and R 3 is an unsubstituted phenylene or a phenylene substituted by one or more of alkyl-, alkoxy- or halogen-substitutions; and R is C 1 -C 4 -alkyl or phenyl.