Dimethylformamide → Ethyl 6-nitro-3-[(trimethylsilyl)ethynyl]-1-benzothiophene-2-carboxylate

Participants

Reaction Conditions

Reaction Steps

DMF (20 ml), (trimethylsilyl)acetylene (5 ml), triethylamine (10 ml) and bis(triphenylphosphine)palladium (II) dichloride (420 mg, 0.6 mmol) were added to ethyl 3-bromo-6-nitro-1-benzothiophene-2-carboxylate obtained in Example (183b) (794 mg, 2.41 mmol) and copper (I) iodide (12 mg, 0.63 mmol), and the mixture was stirred at 80° C. for one hour. The reaction solution was concentrated under reduced pressure, diluted with ethyl acetate, washed with dilute hydrochloric acid and brine, and dried over anhydrous sodium sulfate. Following concentration under reduced pressure, the residue was purified by silica gel column chromatography (elution solvent: ethyl acetate/hexane=1/10) and recrystallized from an ethyl acetate/hexane solvent, to obtain 110 mg of the title compound as crystals.

Provenance & Evidence