Benzo[c]quinoliziniums: A new family of inhibitors for protein kinase CK II

A series of bicyclic enols 3 and tricyclic benzo[c]quinoliziniums 4 and 5 were prepared and evaluated as inhibitors of protein kinase CKII. Of the seventeen derivatives examined, 6-hydroxy-benzo[c]quinolizinium5d was the most potent inhibitor and exhibited a good selectivity for CKII in the micromolar range.