Benzo[b]thiophene-5-ol, 2,3-dihydro- → HCID 14820507, compound

Participants

Reaction Steps

To a solution of BCl3 in methylene chloride (5.5 mL, 1.0M, 5.5 mmole) under N2 at -25° C. was added dropwise a solution of 5-allyloxy-2,3-dihydrobenzothiophene (1.0 g, 5.2 mmole) in methylene chloride (10 mL) keeping the temperature between -25° and -15° C. (10 minutes). The reaction mixture was stirred at -15° C. for 15 minutes. The cooling bath was then removed and the reaction mixture allowed to stir for another 1.5 hours. The reaction mixture was then poured into ice water (70 mL). An additional portion of methylene chloride (10 mL) was added and the layers separated. The aqueous layer was extracted an additional 2×20 mL methylene chloride and the combined organic layers were washed with NaHCO3 (sodium bicarbonate) (1×20 mL), H2O (1×20 mL) and brine (1×20 mL). After drying over Na2SO4, filtration and concentration afforded 0.56 g crude product. Purification by flash chromatography (90/10 hexane/EtOAc to elute) afforded, in order of elution: 64 mg (6.4%) 4-allyl-2,3-dihydrobenzothiophene (oil) 204 mg (20.4% 6-allyl-2,3-dihydrobenzothiophene (oil) and 146 mg (18.4%) 5-hydroxy-2,3-dihydrobenzothiophene.

Provenance & Evidence