Pd-catalyzed cross-coupling/heterocyclization domino reaction: facile access to anthra[2,3-b]furan-5,10-dione scaffold

Synthesis and Characterization of 4,11-Diaminoanthra[2,3-b]furan-5,10-diones: Tumor Cell Apoptosis through tNOX-Modulated NAD+/NADH Ratio and SIRT1

“…A mixture of 4,11-dimethoxyanthra­[2,3- b ]­furan-5,10-dione ( 10 ; , 0.12 g, 0.4 mmol) and ethylenediamine (1.5 mL) in THF (5 mL) was heated at 50 °C for 1.5–2 h. During this time, the yellow color of the reaction mixture changed to dark blue, and after the complete conversion of 10 (as determined by TLC) the solution was cooled and quenched with water. An aqueous solution of HCl (1%) was added to make pH = 8.0, the solution was saturated with NaCl, and the product was extracted with warm n -butanol (3 × 25 mL).…”

“…1 H NMR (400 MHz, DMSO-d 6 ) δ 12.12 (t, 1H, J = 6.4 Hz, NH); 11.34 (t, 1H, J = 6.4 Hz, NH); 9.43 (t, 1H, J = 5.5 Hz, NH), 8.45 (s, 1H, 3-H); 8.30 (br s, 9H, 3NH 3 ); 8.22−8.18 (m, 2H, 6,9-H); 7.78−7.76 (m, 2H, 7,8-H); 4.15 (dd, 2H, J 1 = 6.0, J 2 = 6.4 Hz, HNCH 2 ); 4.04 (dd, 2H, J 1 = 6.0, J 2 = 6.4 Hz, HNCH 2 ); 3.63 (dd, 2H, J 1 = 5.5, J 2 = 6.2 Hz, HNCH 2 ); 3. (21). Ethyldiisopropylamine (DIPEA, 1 mL, 6.0 mmol) and 0.5 g (3.4 mmol) of hydrochloride of pyrazole-1carboxamidine were added to a solution of free base of 11 (0.1 g, 0.24 mmol) in DMSO (10 mL).…”

“…We took advantage of this property for the synthesis of the corresponding derivatives of 4,11-diaminoanthra­[2,3- b ]­furan-5,10-dione. For the introduction of the amino groups, we used 4,11-dimethoxyanthra­[2,3- b ]­furan-5,10-dione ( 10 ), which can be obtained via several alternative routes. , Substitution of methoxy groups in 10 by treatment with ethylenediamine and its derivatives in THF at 50 °C yielded a series of furan-fused analogs 11 – 15 of the anticancer agent ametantrone with different side chains (Scheme ).…”