Lithium borohydride → HCID 86299123, compound

Participants

Reaction Conditions

Reaction Steps

Lithium tetrahydroborate (1.6 mg, 0.071 mmol) was added to ethyl 7-(3,5-dimethylisoxazol-4-yl)-2-oxo-4-pyridin-2-yl-1,2,4,5-tetrahydroimidazo[1,5,4-de][1,4]benzoxazine-5-carboxylate (20 mg, 0.05 mmol), from Example 20, in tetrahydrofuran (3 mL). The reaction was stirred at 70° C. for 3 h, then partitioned between water and ethyl acetate. The organic layer was concentrated and the crude product was purified by FCC on silica gel eluting a hexane:ethyl acetate gradient to obtain the product as a mixture of diastereomers. The isomers were separated by prep chiral column chromatography using the following conditions: Column: phenomenex Lux Cellulose C-2 5 μm, 21, 2×250 mm, Mobile phase: 45% EtOH/Hexanes, Gradient condition: isocratic at 18 mL/min, Loading: 13.5 mg in 900 μL, run time: 18 min, peak time: 9.0, 12.1, 24.2 and 15.0 min.

Provenance & Evidence