The new research work deals with the synthesis of cyclohepta[b]thieno[2,3-e][1,4]diazepine derivatives through three synthetic pathways starting with cycloheptanone. The starting ethyl 2-amino-5,6,7,8-tetrahydro-4Hcyclohepta[ b]thiophene-3-carboxylate (2) and 2-amino-5,6,7,8-tetrahydro-4H-cyclohepta[b] thiophene-3- carboxamide (5) was synthesized adopting a direct Gewald's method. The starting material 2 was reacted with phenacyl bromide and its chloride derivative to afford 3 a&b which further cyclized through the reaction with different aromatic amines to give 4a-e. Also 3-aryl-7,8,9,10-tetrahydro-1H,6H-cyclohepta[b]thieno[2,3-e][1,4] diazepin-5(4-H)-one (7a-f) was furnished via cyclization of 6 with phenacyl bromides. In addition, the reaction of the same starting material 6 with chloroacetyl chloride afforded 9 through the separated intermediate 8. All of the newly synthesized products were subjected to in vitro anticancer screening against human breast cancer cell line (MCF-7), colon cancer cell line (HCT-116) and against human liver carcinoma (HepG-2). Compounds 7 c, 7 e and 7 f were the most active compounds which exhibited antitumor activity against human hepatocellular carcinoma (HepG-2), human breast adenocarcinoma (MCF-7) and human colon carcinoma (HCT-116) cell lines, with IC50’s ranging from 4.4-13 μg/mL in a comparison to slandered vinblastine.