N,N'-Dimethylethylenediamine → Benzo[b]thiophene-3-carbonitrile

Participants

Reaction Conditions

Reaction Steps

An oven dried screw cap test tube was charged with NaCN (60 mg, 1.225 mmol), dried KI (34 mg, 0.205 mmol, 20 mol %) and CuI (20 mg, 0.105 mmol, 10 mol %), evacuated and backfilled with argon three times. 3-Bromo-benzo[b]thiophene (135 μL, 1.032 mmol), N,N′-dimethylethylenediamine (110 μL, 1.033 mmol) and anhydrous toluene (700 μL) were added under argon. The tube was sealed and the reaction mixture was stirred magnetically at 110° C. for 24 h. The resulting suspension was cooled to room temperature, 2 mL of ethyl acetate, 1 mL of ammonium hydroxide (30%) and 1 mL of water were added. The mixture was stirred at 25° C. for 10 min, then the organic layer was separated and the aqueous layer was extracted three times with ethyl acetate (3×2 mL). The combined organic layers were washed with 5 mL of water and dried over MgSO4. The solvent was removed at reduced pressure. Purification of the residue by flash chromatography on silica gel (2×15 cm; hexane/ethyl acetate 10:1) provided 122 mg (74% yield) of the title compound as a pale yellow solid.

Provenance & Evidence