Cyclopropylacetylene → 2-cyclopropyl-1H-indole

Participants

Reaction Conditions

Reaction Steps

To a solution of N-(2-iodophenyl)acetamide (100 mg, 0.38 mmol) in dioxane (750 mL) and 1,1,3,3-tetramethylguanidine (750 mL) was added cyclopropylacetylene (41 mL, 0.49 mmol), bis(triphenylphosphine)palladium(II) chloride (35 mg, 0.05 mmol), and copper(I) iodide (10 mg, 0.05 mmol). The reaction was stirred overnight at 80° C. The solution was cooled and partitioned between water and methylene chloride. The organic layer was dried (MgSO4) and concentrated to give the uncyclized Sonagashira coupling product. Dioxane (750 mL) and 1,1,3,3-tetramethylguanidine (750 mL) were added and the reaction was stirred overnight at 90° C. The solution was again partitioned between water and methylene chloride. The organic layer was dried (MgSO4) and concentrated to give the desired indole, which was used without further purification.

Provenance & Evidence