Sodium Bicarbonate → methyl 6-cyclohexyl-5-(3-nitro-2-[2-(tetrahydropyran-2-yloxy)ethoxy]phenyl}-4H-thieno[3,2-b]pyrrole-2-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a solution of 2-[2-(2-bromo-6-nitrophenoxy)ethoxy]tetrahydropyran (1.29 g, 3.72 mmol) in water (10 ml) and ethylene glycol dimethyl ether (20 ml) were added sodium hydrogen carbonate (1.23 g, 14.8 mmol) and tetrakis(triphenylphosphine)palladium (430 mg, 0.372 mmol). Methyl 6-cyclohexyl-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-4H-thieno[3,2-b]pyrrole-2-carboxylate (1.60 g, 4.10 mmol) obtained in Step 1 was divided in 4 portions and added every 30 min while stirring at 90° C. with heating. After the completion of addition, the mixture was further stirred at 90° C. for 4 hr. The reaction mixture was allowed to cool to room temperature and water was added. The mixture was extracted with ethyl acetate and the organic layer was washed with water and saturated brine in this order, and dried over anhydrous sodium sulfate. After filtration, the solvent was evaporated under reduced pressure. The residue was purified by silica gel column chromatography (hexane:ethyl acetate=6:1-3:1) to give methyl 6-cyclohexyl-5-{3-nitro-2-[2-(tetrahydropyran-2-yloxy)ethoxy]phenyl}-4H-thieno[3,2-b]pyrrole-2-carboxylate (863 mg, yield 44%).

Provenance & Evidence