Fig. 5. Synthesis of chalcone small molecules and investigations into possible synergy with 6-thiopurine for either increased cytotoxicity or expansion of therapeutic application scope. A) General synthesis route employed to gain access to the three chalcones 11a–c. Synthetic procedures: a. MOMCl (2.2 eq.), DIPEA, CH₂Cl₂, b. MOMCl (3.3 eq.), DIPEA, CH₂Cl₂, and c. Me₂SO₄, K₂CO₃, acetone. B) General cytotoxicity of chalcones 11a–c in HeLa (cervical), A549 (lung), MIA PaCa-2 (pancreatic), U937 (lymphoma), and Reh (acute lymphocyte leukemia) cancerous cell lines. C) Results of the average cell death induced by 11c & 6-thiopurine combinations evaluated in the 3 × 5 matrix and corresponding quantification of synergy with CI values (n = three biologic replicates).