A compound of formula (I) or a pharmaceutically acceptable salt or prodrug thereof: wherein R1 is CN; R2 is H or F; R3 and R4 are independently hydrogen, fluorine, chlorine or OR8; R5 is hydrogen, C1-6 alkyl, C1-6 alkenyl or C1-6 alkynyl; R6 and R7 are independently hydrogen, halogen, OR8 or NR9R10; R8 is hydrogen or C1-6 alkyl; R9 and R10 are independently hydrogen or C1-6 alkyl; or the groups R9 and R10 when they are attached to a nitrogen atom may together form a 5- or 6-membered ring which optionally contains one further heteroatom selected from NR8, S and O said 5 or 6 membered ring being optionally substituted by hydroxyl or C1-6 alkoxy; or the groups R9 and R10 when they are attached to a nitrogen atom may together form an azetidinyl ring optionally substituted by hydroxyl or C1-6 alkoxy, is provided. The use of such compounds in treating amyloid-related disease is also disclosed.