Cesium carbonate → (2R,4S,4aS)-rel-11-fluoro-2,4-dimethyl-8-phenyl-1,2,4,4a-tetrahydro-2'H,6H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5'-pyrimidine]-2',4',6'(1'H,3'H)-trione

Participants

Reaction Conditions

Reaction Steps

Cs2CO3 (130 mg, 0.0004 mmol) was added to a solution of (2R,4S,4aS)-rel-9,10-difluoro-8-[(E)-(hydroxyimino)(phenyl)methyl]-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione (Intermediate 29, 100 mg, 0.0002 mmol) in DMF (1.5 mL), and the mixture was heated to 100° C. for 14 h. The reaction mixture was cooled to room temperature and filtered through a Celite bed. The solvent was removed, and the residue was subjected to reverse phase prep-HPLC purification (10 mM ammonium acetate in water, CH3CN) providing the title compound as a racemic mixture. Yield: 9.97 g (9%).

Provenance & Evidence