Synthesis of dicationic diarylpyridines as nucleic-acid binding agents.

The syntheses of 2,6-bis[4-(4,5-dihydro-1H-imidazol-2-yl)phenyl]pyridine 7, 2-[4-(4,5-dihydro-1H-imidazol-2-yl)-phenyl]-6-[3-(4,5-dihydro-1H-imidazol-2-yl)phenyl]pyridine 8 and 2,6-bis[3-(4,5-dihydro-1H-imidazol-2-yl)phenyl]pyridine 9 in five steps from the appropriately substituted bromoacetophenone are described. 3,5-Bis[4-(4,5-dihydro-1H-imidazol-2-yl)phenyl]pyridine 13 is also reported, prepared in four steps from 4-bromophenylacetonitrile. The preparation of 2,5-bis[4-(4,5-dihydro-1H-imidazol-2-yl)-phenyl]pyridine 18 from 4-bromoacetophenone in six steps is presented. The dications bind to poly dA·dT in the order 7 > 13 > 18 > 8 > 9; the order of binding to poly A·U is 7 > 13 > 8 > 9; 18 essentially does not bind to the RNA model. Only 7 inhibits topoisomerase II at millimolar concentrations. The dicationic compounds that were tested against Pneumonocystis carinii in the immuno-suppressed rat model show only modest activity and are moderately toxic. Some of the compounds demonstrated modest anti-HIV-1 activity and selectivity in primary lymphocytes.

Synthesis of dicationic diaryltriazines nucleic acid binding agents.

- The synthesis of 2,4-bis[4-(4,5-dihydro-1H-imidazol-2-yl)phenyl]-1,3,5-triazine 6a and 2,4-bis[4-(1,4,5,6-tetrahydropyrimidin-2-yl)phenyl]-1,3,5-triazine 6b in 3 steps from either 4-bromobenzamidine or 4-(carbamoyl)benzamidine is reported. The synthesis of 4,6-bis[4-(4,5-dihydro-1H-imidazol-2-yl)phenyl]-2-dimethylamino-1,3,5-triazine 9a and 4,6-bis[4-(1,4,5,6-tetrahydropyrimidin-2-yl)phenyl]-2-dimethylamino-1,3,5-triazine 9b in 2 steps from 1,4-dicyanobenzene is also described. The compounds 6b and 9b bind strongly to DNA model sequences and inhibit topoisomerase II from 2 microbial sources. Compounds 6a and 9a bind to both DNA and RNA model sequences whereas 6b and 9b essentially do not bind to the RNA model.