Tetrabutylammonium Fluoride → 8-(1-((3,5-difluorophenyl)(methyl)amino)ethyl)-6-(4-hydroxypiperidine-1-carbonyl)-2-morpholino-4H-chromen-4-one

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Reaction Steps

Tetrabutylammonium fluoride (1N in THF) (7.83 mL, 7.83 mmol) was added dropwise to a stirred solution of 6-(4-(tert-butyldiphenylsilyloxy)piperidine-1-carbonyl)-8-(1-((3,5-difluorophenyl)(methyl)amino)ethyl)-2-morpholino-4H-chromen-4-one (3 g, 3.92 mmol, enantiomer 2 in Example 7.0a, [α]D20°: −102°) dissolved in THF (20 mL) at RT under nitrogen and stirred for 2 hrs. The mixture was evaporated to dryness, diluted with DCM, washed with water. The organic phase was washed with brine, dried over magnesium sulfate, filtered and concentrated. The crude product was purified by flash chromatography on silica gel (80 g) eluting with 3 to 7% MeOH in DCM. The solvent was evaporated to dryness to give a foam which was triturated in ether (2-5 mL). The resulting white solid was collected by filtration and dried to give 8-(1-((3,5-difluorophenyl)(methyl)amino)ethyl)-6-(4-hydroxypiperidine-1-carbonyl)-2-morpholino-4H-chromen-4-one enantiomer 2 (1.7 g, 82%) as a white solid. Mass Spectrum: M+H+ 528. [α]D20°: +7° in MeCN.

Provenance & Evidence