A compound of formula (I) or a pharmaceutically acceptable salt or prodrug thereof: wherein R is CN； R is H or F； R and R are independently hydrogen, fluorine, chlorine or OR； R is hydrogen, C alkyl, C alkenyl or C alkynyl； Rand R are independently hydrogen, halogen, OR or NRR； R is hydrogen or C alkyl； R and R are independently hydrogen or C alkyl； or the groups R and R 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 NR, S and O said 5 or 6 membered ring being optionally substituted by hydroxyl or C alkoxy； or the groups R and R when they are attached to a nitrogen atom may together form an azetidinyl ring optionally substituted by hydroxyl or C alkoxy, is provided. The use of such compounds in treating amyloid-related disease is also disclosed.
