1,4-Dioxane → (S)-2'-(neopentyloxy)-7'-(pyrazin-2-yl)-5H-spiro[oxazole-4,9'-xanthen]-2-amine

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Reaction Steps

A vial was charged with (R)-2′-bromo-7′-(neopentyloxy)-5H-spiro[oxazole-4,9′-xanthen]-2-amine (55.6 mg, 0.133 mmol), tetrakis(triphenylphosphine)palladium (0) (15.40 mg, 0.013 mmol), 2-(tributylstannyl)pyrazine (148 mg, 0.400 mmol), and dioxane (0.7 mL). The vial was sealed under a blanket of Ar gas and placed in a 100° C. oil for 16 h. The mixture was then cooled and filtered through celite. The filtrate was evaporated, and the residue was purified by chromatography on a 12-g Redi-Sep column, eluting with 0-10% MeOH/DCM to give a brown oil. This oil was dissolved in MeOH and filtered through a 2 micron filter, then purified further by reverse-phase HPLC (10-90% CH3CN/H2O with 0.1% TFA). The product containing fractions were combined in saturated aqueous sodium bicarbonate solution with the aid of MeOH. The mixture was extracted with DCM (2×), and the combined organic extracts were dried over sodium sulfate, filtered, and evaporated to give (S)-2′-(neopentyloxy)-7′-(pyrazin-2-yl)-5H-spiro[oxazole-4,9′-xanthen]-2-amine as a white solid. MS m/z=417.2 [M+H]+. Calc'd for C24H25N4O3: 417.19.

Provenance & Evidence