Dimethyl Sulfoxide → 2-bromo-4-(4-chlorophenyl)-4H-cyclopenta[b]thiophen-6(5H)-one

Participants

Reaction Conditions

Reaction Steps

To a 500 mL round bottom flask was added a solution of methyl 2-bromo-4-(4-chlorophenyl)-6-oxo-5,6-dihydro-4H-cyclopenta[b]thiophene-5-carboxylate (3.96 g, 10.3 mmol) in dimethyl sulfoxide (88.393 mL, 1245.6 mmol). Water (4.420 mL, 245.3 mmol) was added and the reaction mixture was heated to 150° C. and allowed to stir for 3 hours. The reaction was cooled to ambient temperature and quenched by the addition of a saturated aqueous solution of sodium bicarbonate (500 mL) and extracted with EtOAc (300 mL×3). The combined organic layers were dried over anhydrous Na2SO4, filtered and concentrated under reduced pressure. The crude material was dry loaded onto silica gel and then purified using a ISCO (40 g cartridge, gradient hexanes to 100% EtOAc over 30 min) to afford the title compound (2.91 g, 82%) as a brown oil. LC/MS (AA) ES− 327, 329, 331. 1H NMR (dmso-d6, 400 MHz): δ 7.40-7.38 (m, 2H), 7.31 (s, 1H). 7.24-7.22 (m, 2H), 4.67 (dd, 1H), 3.40 (dd, 1H), 2.72 (dd, 1H).

Provenance & Evidence