2-Chloroethanol → 4-(2-chloroethoxy)-1H-indole

Participants

Reaction Steps

To a solution of 4-hydroxyindole (4 g, 30 mmol), 2-chloroethanol (4.83 g, 60 mmol), triphenylphosphine (15.7 g, 60 mmol) in anhydrous tetrahydrofuran (40 ml) was slowly added diisopropyl azodicarboxylate (12.1 g, 60 mmol). The reaction was allowed to stir for 2.5 hours at room temperature, then poured into methylene chloride (250 ml), washed with water (3×100 ml) and dried over anhydrous sodium sulfate. This material was filtered and the solvent was removed under vacuum. Chromatography (20% hexanes-ethyl acetate) to remove triphenylphosphine, (20% methylene chloride-hexanes) afforded 2.94 g (50%) of product as a white solid: mp 69.5-72° C.

Provenance & Evidence