. . . "-(C1-C3)-alkyl, wherein one, two or three hydrogen atoms may be substituted by a halogen or hydroxyl, -(C1 -C3)-O-(C1-C3), -(C1-C3)-O-(C1-C3), wherein one, two or three hydrogen atoms may be substituted by a halogen, or R is a group wherein R3 and R4 both together or independently are halogen, hydroxyl, -(C1-C3)alkyl, wherein one, two or three hydrogen atoms may be substituted by a halogen or hydr" . .