Sodium cyanoborohydride → HCID 66868381, compound

Participants

Reaction Steps

To a mixture of ethyl 5-chloro-1H-indole-7-carboxylate (3.0 g) and acetic acid (30 mL) was added sodium cyanoborohydride (2.5 g), followed by stirring at room temperature for 19 hours. The reaction mixture was concentrated under reduced pressure, and the residue was adjusted to pH 8 by adding saturated aqueous sodium bicarbonate. After extraction with chloroform, the organic layer was dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The residue was added with diethyl ether/hexane (1/5), solidified, and collected by filtration. To this solid was added ethyl acetate (10 mL), and 4 M hydrogen chloride ethyl acetate (10 mL) was added thereto, followed by concentration under reduced pressure. To the residue was added diethyl ether/hexane mixture (1/5), and the solid was collected by filtration and dried under reduced pressure to obtain ethyl 5-chloroindoline-7-carboxylate hydrochloride (1.6 g).

Provenance & Evidence