Iron modulator compounds of formula (I) are provided for treating amyloidoses wherein R.sup.1 is selected from H, C.sub.1-6 alkyl, C.sub.1-6 alkenyl, C.sub.1-6 hydroxyalkyl, C.sub.1-6 hydroxyalkenyl, R.sup.2 is selected from H, C.sub.1-6 alkyl, C.sub.1-6 alkenyl, C.sub.1-6 hydroxyalkyl, C.sub.1-6 hydroxyalkenyl and C.sub.6-10 aralykyl in which the aryl group of the aralkyl group is optionally substituted by hydroxy, halo or C1-4 alkyl R.sup.3 is selected from H, C.sub.1-6 alkyl, C.sub.1-6 alkenyl and C.sub.1-12 acyl; R.sup.4 is selected from H and C.sub.1-3 alkyl R.sup.5, R.sup.6 and R.sup.7 are independently selected from H, C.sub.1-6 alkyl, C.sub.3-7 aryl, and C.sub.1-10 aralkyl; the alkyl, aryl and aralkyl groups being optionally substituted by one or more halo, hydroxy and nitro groups or R.sup.5 and R.sup.7 together with the nitrogen atom to which they are bonded form a heterocyclic ring optionally substituted by one or more hydroxyl groups or a pharmaceutically acceptable tautomer, ester or addition salt thereof.