One-pot Suzuki-Miyaura coupling/aldol condensation cascade reactions of 3-acetyl-2-bromo-1-azaazulene (1b) with 2-formylphenylboronic acid and the reaction of 2-bromo-3-formyl-1-azaazulene (6b) with 2-acetylphenylboronic acid gave 5-azacyclohepta[b]benz[h]azulen-11(11H)-one (5) and 5-azacyclohepta[b]benz[h]azulen-13(13H)-one (8), respectively, in good yields. The 13-hydroxy-12,13-dihydro-derivative (4) of 5 was isolated as an intermediate in the former reaction. Similar reaction of 1b with 2-formylthiophene-3-boronic acid under similar conditions gave 4-aza-1-thia-1,10-dihydroazuleno[2,1-e]azulen-10-one (10) in high yield. Similar reaction of 1b with 3-formythiophene-2-boronic acid did not give a corresponding cyclization product, instead 3-acetyl-1-azaazulen-2(1H)-one was obtained. Compounds (4, 5, and 10) showed strong cytotoxic activity against HeLa S3 cells, whereas compound (8) did not show the cytotoxic activity.