[Synthesis and pharmacologic study of pyridazino[4,5-b]carbazoles]

Cyclization reaction of hydrazine with carbazole-2,3-methyl dicarboxylates gave 1,4-dioxo-1,2,3,4-tetrahydropyridazino[4,5-b]carbazoles. Chlorodehydroxylation provided 1,4-dichloropyridazino[4,5-b]carbazoles and nucleophilic substitution gave 1,4-dialkoxy pyridazino[4,5-b]carbazoles. These compounds were tested for cytotoxic activity against L1210 leukemia in mice.