In our laboratory, a series of 3,6-substituted-9-benzyl carbazole derivatives were synthesized, and we found that some of these carbazole derivatives showed significant cytotoxic effects on human leukemia cells. Following the previous results, a series of 3,6-substituted-9-picolyl carbazole derivatives was synthesized. Initially, reaction of carbazole (1) with appropriate picolyl chlorides yielded the corresponding compounds 9-(2-picolyl) carbazole (2), 9-(3-picolyl) carbazole (3) and 9-(4-picolyl) carbazole (4). Subsequently, compounds 1—4 underwent Vielsmeir formylation by treating with POCl3/DMF to give corresponding carboxaldehydes 1a—4a, and compounds 1—4 was to afford the corresponding 3-acetylated products 1b—4b. Among these compounds, 2b, 3b and 4b showed potential effective on A549 cells, 3b showed the most potential effect on HA22T cells. Furthermore, we found that compounds 2b, 3b and 4b had significant cell differentiating effect on HL-60 cells. These finding demonstrated that these novel synthesized compounds could be developed as novel anticancer agents.
