Trifluoroacetic acid → 3-(6-hydroxy-4-methyl-3,4-dihydro-2H-1,4-benzoxazin-7-yl)-1-[(2R)-tetrahydrofuran-2-ylmethyl]-1,3-dihydro-2H-indol-2-one trifluoroacetate

Participants

Reaction Steps

To a cooled (0° C.) solution of triethylsilane (1.3 mL, 8.2 mmol) in trifluoroacetic acid (8 mL) was added dropwise a solution of 3-hydroxy-3-(6-hydroxy-4-methyl-3,4-dihydro-2H-1,4-benzoxazin-7-yl)-1-[(2R)-tetrahydrofuran-2-ylmethyl]-1,3-dihydro-2H-indol-2-one (1.04 g, 2.62 mmol) in dichloromethane (3 mL). The resulting solution was warmed to reflux and stirred under nitrogen for 90 min. Once cooled, the solvent was removed under reduced pressure to afford 3-(6-hydroxy-4-methyl-3,4-dihydro-2H-1,4-benzoxazin-7-yl)-1-[(2R)-tetrahydrofuran-2-ylmethyl]-1,3-dihydro-2H-indol-2-one trifluoroacetate as a light brown foam: MS (ES+) m/z 381.0 (M+1).

Provenance & Evidence