The present invention provides a fused heterocyclic compound having a tyrosine kinase inhibitory action, which is represented by the formula:
wherein
R1 is a hydrogen atom, a halogen atom, or an optionally substituted group bonded via a carbon atom, a nitrogen atom or an oxygen atom;
R2 is a hydrogen atom, or an optionally substituted group bonded via a carbon atom or a sulfur atom, or
R1 and R2, or R2 and R3 are optionally bonded to each other to form an optionally substituted ring structure;
R3 is a hydrogen atom or an optionally substituted aliphatic hydrocarbon group, or
R3 is optionally bonded to the carbon atom on ring A to form an optionally substituted ring structure;
ring A is an optionally substituted benzene ring; and ring B is
(i) an optionally substituted fused ring, or
(ii) a pyridine ring having optionally substituted carbamoyl (the pyridine ring is optionally further substituted).