Dimethylformamide → (S)-2-amino-4'-fluoro-7'-(pyrimidin-5-yl)-5H-spiro[oxazole-4,9'-xanthen]-2'-ol

Participants

Reaction Conditions

Reaction Steps

A 25 ml RBF was charged with (S)-2-amino-7′-bromo-4′-fluoro-5H-spiro[oxazole-4,9′-xanthen]-2′-ol (629 mg, 1.723 mmol), tetrakis(triphenylphosphine)palladium (199 mg, 0.172 mmol), and pyrimidin-5-ylboronic acid (320 mg, 2.58 mmol). DMF (8613 μL) and sodium carbonate (2M solution) (2584 μL, 5.17 mmol) were added and the mixture was stirred at 85° C. for 2.5 hrs. The mixture was cooled to RT, water (˜5 ml) was added and stirring was continued for 10 min. The precipitate was filtered out, washed with water (3×5 mL), 1:1 i-PrOH/water to remove color and dried in vacuo to afford (S)-2-amino-4′-fluoro-7′-(pyrimidin-5-yl)-5H-spiro[oxazole-4,9′-xanthen]-2′-ol as yellow solid. Step 2: A vial was charged with (S)-2-amino-4′-fluoro-7′-(pyrimidin-5-yl)-5H-spiro[oxazole-4,9′-xanthen]-2′-ol (61.0 mg, 0.167 mmol), cesium carbonate (82 mg, 0.251 mmol), and DMF (670 μL). The resulting mixture was stirred vigorously for 10 min, then the vial was placed in large ice-bath for 10 min and 2-fluoro-2-methylpropyl trifluoromethanesulfonate (33.3 μL, 0.201 mmol) was added dropwise. The ice bath was removed after 5 minutes and the mixture was stirred at RT for 6 hours before being diluted with water (10 mL) and extracted with EtOAc (3×5 mL). The combined organic extracts were dried over sodium sulfate, filtered, and evaporated. The residue was chromatographed on a 12 g Redi-Sep column, eluting with 5-60% gradient of DCM/MeOH/NH4OH (90:10:1) in DCM to give (S)-4′-fluoro-2′-(2-fluoro-2-methylpropoxy)-7′-(pyrimidin-5-yl)-5H-spiro[oxazole-4,9′-xanthen]-2-amine as an off-white solid.

Provenance & Evidence