The subject invention provides compounds having the structure: wherein R1 is substituted or unsubstituted phenyl or a 5-6 membered heterocyclic or heteroaromatic ring containing from 1 to 5 heteroatoms; R2 is hydrogen, or a substituted or unsubstituted alkyl, —C(O)-alkyl, —C(O)—O-alkyl, alkoxy, cycloalkyl, alkenyl, monocyclic or bicyclic aryl, heteroaryl or heterocyclic moiety; R3 is hydrogen, or a substituted or unsubstituted alkyl, —C(O)-alkyl, —C(O)—O-alkyl, alkoxy, cycloalkyl, alkenyl, monocyclic or bicyclic aryl, heteroaryl or heterocyclic moiety, or R2 and R3 are joined to form a heterocyclic ring; wherein the dashed line represents a second bond which may be present or absent, and when present R3 is oxygen; R4 and R5 are each independently substituted or unsubstituted alkyl, —C(O)-alkyl, —C(O)—O-alkyl, alkoxy, cycloalkyl, alkenyl, monocyclic or bicyclic aryl, heteroaryl or heterocyclic moiety, or R4NR5 together form a substituted or unsubstituted monocyclic or bicyclic, heterocyclic or heteroaryl moiety containing from 1 to 6 heteroatoms; R12 is hydrogen, alkyl, halogen or cyano; and n is 0, 1, 2, 3 or 4, or an enantiomer, or a specific tautomer, or a pharmaceutically acceptable salt thereof and a method for treating a disease associated with the A2b adenosine receptor by administering a therapeutically effective amount of the compounds of the invention.