Indole → (1-Pentyl-1H-indol-3-yl)(2,2,3,3-tetramethylcyclopropyl)methanone

Participants

Reaction Conditions

Reaction Steps

Indole 1 (11.7 g, 100 mmol) was dissolved in diethylether (100 ml) under nitrogen atmosphere and cooled to 0° C. 3M solution of MeMgBr (35 ml, 105 mmol) was added drop-wise and allowed to stir at room temperature for 3 hours. In the meantime, 2,2,3,3-tetramethylcyclopropane carboxylic acid (14.22 g, 100 mmol) was dissolved in thionyl chloride (100 ml) and refluxed for 90 min, then the solvent was removed under vacuo and the residue was dissolved in diethylether (100 ml). The resulting solution was added drop-wise to the indole reaction mixture at 0° C. and then allowed to stir at room temperature for 2 hours. A solution of ammonium chloride (200 ml) was added to the reaction mixture and the resulting mixture was stirred at room temperature overnight. The reaction mixture was extracted with ethyl acetate (3×200 ml). The combined organic extracts were washed by water, brine, dried over sodium sulfate, filtered and evaporated to dryness. The crude was purified by column chromatography (silica gel: 10-30% ethyl acetate in hexane) to give 8.6 g (36%) of N-desalkyl UR-144 2 as a cream solid.

Provenance & Evidence