The present disclosure relates to a compound of formula (I) wherein: A is an optionally substituted monocyclic or polycyclic aryl or heteroaryl group; B is an optionally substituted monocyclic nitrogen-containing heteroaryl group; and either a) R1 and R2 are chosen from a hydrogen atom and specified substituents, or b) R2, R1 and the —NH— group to which R1 is attached, form a moiety chosen from the moiety of formulae (IIa) and (IIb): or a pharmaceutically acceptable salt thereof, or a N-oxide thereof. The present disclosure also relates to a method for treating a subject afflicted with a pathological condition or disease susceptible to amelioration by antagonism of the A2B adenosine receptor.