Sodium borohydride → 5-[(1R)-2-{4-[2-(1,1-dioxido-2,3-dihydro-1-benzothiophen-5-yl)-2-hydroxyethyl]piperazin-1-yl}-1-hydroxyethyl]-4-methyl-2-benzofuran-1(3H)-one

Participants

Reaction Steps

To a solution of 5-[(1R)-2-{4-[2-(1,1-dioxido-2,3-dihydro-1-benzothiophen-5-yl)-2-oxoethyl]piperazin-1-yl}-1-hydroxyethyl]-4-methyl-2-benzofuran-1(3H)-one (56 mg, 0.12 mmol) in 3 mL MeOH was added sodium borohydride (4.4 mg, 0.12 mmol) portion wise. The reaction was allowed to stir at ambient temperature for one hour, quenched by the addition of water and then concentrated in vacuo. The crude residue was dissolved in DCM/water mixture. The aqueous layer was extracted three times with DCM (10 mL). The organic layers were dried over sodium sulfate, filtered and concentrated in vacuo. The crude residue was purified via MPLC (10% DCM/MeOH) to afford 5-[(1R)-2-{4-[2-(1,1-dioxido-2,3-dihydro-1-benzothiophen-5-yl)-2-hydroxyethyl]piperazin-1-yl}-1-hydroxyethyl]-4-methyl-2-benzofuran-1(3H)-one as a mixture of diastereomers.

Provenance & Evidence