Buspirone → 6-Hydroxybuspirone

Participants

Reaction Conditions

Reaction Steps

Buspirone (19.3 g, 50 mmole) was dissolved in dry THF (400 mL) and the resulting solution was cooled to −78° C. A solution of KN(SiMe3)2 in toluene (100 mL, 1 M) was added slowly. After the reaction mixture was stirred at −78° C. for 1 h, a solution of 2-(phenylsulfonyl)-3-phenyloxaziridine (Davis reagent, prepared according to literature method: F. A. Davis, et al., Org. Synth., 1988, 66, 203) (17.0 g, 65 mmole) in dry THF (150 mL, precooled to −78° C.) was added quickly via a cannular. After stirred for 30 mins at −78° C., the reaction was quenched with 1 N HCl solution (500 mL). It was extracted with EtOAc (3×500 mL). The aqueous layer was separated, neutralized with saturated sodium bicarbonate solution, and extracted with EtOAc (3×500 mL). The combined organic extracts were dried over Na2SO4, filtered, and concentrated under reduced pressure to give a white solid residue which was subjected to column chromatography using CH2Cl2/MeOH/NH4OH (200:10:1) as the eluent to give pure 6-hydroxy-buspirone (I, 7.2 g) and a mixture of buspirone and 6-hydroxy-buspirone (I). The mixture was purified by above column chromatography to afford another 3.3 g of pure 6-hydroxy-buspirone (I).

Provenance & Evidence