Methanol → HCID 57870183, compound

To a 0° C. solution of (3aRS,7aSR)-7-((1R)-1-phenyl-ethyl)-tetrahydro-2,4-dioxa-7-aza-inden-6-one (1.46 g, 5.9 mmol) in tetrahydrofuran (20 ml), a 1 M-solution of boran tetrahydrofuran complex in tetrahydrofuran (18 ml, 18 mmol) was added dropwise under nitrogen atmosphere and the resulting mixture was warmed to room temperature. After the reaction mixture was stirred for 15 hours, methanol was added until disappearance of bubbles. The mixture was concentrated under reduced pressure and methanol (10 ml) and 1 N aqueous solution of sodium hydroxide (10 ml) were added to the obtained residue at room temperature. The white slurry was refluxed for 2 hours and cooled to room temperature. After evaporation of methanol, water (30 ml) was added to the residue and extractive workup with ethyl acetate was performed. The organic layer was dried over sodium sulfate and concentrated. (3aS,7aR)-7-((1R)-1-phenyl-ethyl)-hexahydro-2,4-dioxa-7-aza-indene was isolated as a diastereomerically enriched colorless crystalline by silica gel column chromatography (eluent; hexane/ethyl acetate=100/0 to 1/1) of the residue and subsequent recrystallization from ethanol (1.0 g, 4.9 mmol, 73%, 96% de determined by NMR analysis).

1. concentrationThe mixture was concentrated under reduced pressure and methanol (10 ml) and 1 N aqueous solution of sodium hydroxide (10 ml)
2. additionwere added to the obtained residue at room temperature
3. temperatureThe white slurry was refluxed for 2 hours
4. temperaturecooled to room temperature
5. customAfter evaporation of methanol, water (30 ml)
6. additionwas added to the residue and extractive workup with ethyl acetate
7. dry with materialThe organic layer was dried over sodium sulfate
8. concentrationconcentrated

ORD record

ord-89b29ae1a041406ebd7da425dc16425b

Source dataset

uspto-grants-2013_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08569294B2