Hydrogen Peroxide → HCID 118599754, compound

Temperature

-78 °C

A 1 M solution of lithium triethylhydroborate (13.75 mL, 13.75 mmol) in THF was added dropwise to a solution of tert-butyl 7-chloro-3-oxo-2,3-dihydro-4H-1,4-benzoxazine-4-carboxylate (Intermediate 16, 3.25 g, 11.5 mmol) in anhydrous THF (60 mL) at −78° C. under N2 (g). After stirring at −78° C. for 45 min, the mixture was treated with Na2CO3 (sat. aq., 25 mL); then H2O2 (35% in aq, 25 mL) was slowly added at −15° C. The mixture was stirred at rt over night, then filtered. The filtrate was concentrated in vacuo and the residue was extracted with EtOAc (2×100 mL). The organic phase was washed with brine (100 mL), dried by passage through a phase separator, and concentrated under reduced pressure giving the title compound (3.29 g, 101%) as an off-white solid that was used without further purification.

1. stirringThe mixture was stirred at rt over night
2. filtrationfiltered
3. concentrationThe filtrate was concentrated in vacuo
4. extractionthe residue was extracted with EtOAc (2×100 mL)
5. washThe organic phase was washed with brine (100 mL)
6. customdried by passage through a phase separator
7. concentrationconcentrated under reduced pressure

ORD record

ord-42d1e842d34b4140a113c887fe9c5d08

Source dataset

uspto-grants-2016_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09394291B2