The invention provides a compound which is an amide of the formula (1), or a salt, solvate, N-oxide or tautomer thereof; wherein: a is 0 or 1; b is 0 or 1 : provided that the sum of a and b is 0 or 1; T is O or NH Ar<1> is a monocyclic or bicyclic 5- to 10-membered aryl or heteroaryl group containing up to 4 heteroatoms selected from O, N and S, and being optionally substituted by one or more substituents R<1>; Ar<2> Js a monocyclic or bicyclic 5- to 10-membered aryl or heteroaryl group containing up to 4 heteroatoms selected from O, N and S and being optionally substituted by one or more substituents R<2>; and R<1> and R<2>are as defined in the claims. The compounds are inhibitors of kinases and in particular FLT3, FLT4 and Aurora kinases.