5-substituted aminopyrimido [6′,1′:2,3] imidazo [4,5-c] [2,6] naphthyridine compounds as CK2 inhibitors

A method of inhibiting CK2 enzyme activity in a patient, comprising administering to a patient in need thereof a therapeutically effective amount of a compound having the formula I:

• or a pharmaceutically acceptable salt or stereoisomer thereof, wherein:
• R is selected from the group consisting of —Ar, —CH2Ar, —CH2CH2Ar, —COAr, —SO2Ar, —CH2CH2NHR3, —CH2CH2NR3R4, —CH2CH2CH2NHR3, —CH2CH2CH2NR3R4, —COCH2CH2NHR3, —COCH2CH2NR3R4, —COCH2CH2CH2NHR3, —COCH2CH2CH2NR3R4, —SO2CH2CH2NHR3, —SO2CH2CH2NR3R4, —SO2CH2CH2CH2NHR3, and —SO2CH2CH2CH2NR3R4;
• Ar is an aryl ring or a 5 or 6 membered heteroaryl ring, either of the aryl ring or the heteroaryl ring being optionally substituted with one or more substituents selected from the group consisting of halogen, cyano, hydroxy, —OR1, —NH2, —NHR1, —NR1R2, —CONH2, —CONHR1, —CONR1R2, —SO2NH2, —SO2NHR1, —SO2NR1R2, —NHCOR1, —NHCO2R1, —NHCONHR1, —NHSO2NHR1, —NHSO2R1, —COR1, —CO2R1, a C1-C6 straight chain alkyl, a C1-C6 branched alkyl, a C3-C6 cycloalkyl, a halo-C1-C6 straight chain alkyl, a halo-C1-C6 branched alkyl, a halo-C3-C6 cycloalkyl, a cyano-C1-C6 straight chain alkyl, a cyano-C1-C6 branched chain alkyl, and a cyano-C3-C6 cycloalkyl;
• R1 and R2 are each independently selected from the group consisting of hydrogen, a C1-C6 straight chain alkyl, a C1-C6 branched alkyl, a C3-C6 cycloalkyl, a halo-C1-C6 straight chain alkyl, a halo-C1-C6 branched alkyl, a halo-C3-C6 cycloalkyl, a cyano-C1-C6 straight chain alkyl, a cyano-C1-C6 branched alkyl, and a cyano-C3-C6 cycloalkyl;
• and
• R3 and R4 are each independently selected from the group consisting of hydrogen, a C1-C6 straight chain alkyl, a C1-C6 branched alkyl, a C3-C6 cycloalkyl, a halo-C1-C6 straight chain alkyl, a halo-C1-C6 branched alkyl, a halo-C3-C6 cycloalkyl, a cyano-C1-C6 straight chain alkyl, a cyano-C1-C6 branched alkyl, and a cyano-C3-C6 cycloalkyl, or wherein R3 and R4, together with a nitrogen atom to which they are attached, form a nitrogen-containing heterocycle, such nitrogen-containing heterocycle being optionally substituted with from one to three substituents independently selected from the group consisting of a straight or branched C1-C6 alkyl group, a halogen atom, a straight or branched C1-C6 alkoxy group, a straight or branched C1-C6 trihaloalkyl group, and a hydroxy group.