Potassium Carbonate → (S)-2'-amino-3-p-tolyl-5'H-spiro[chromeno[2,3-b]pyridine-5,4'-oxazol]-7-ol

Participants

Reaction Steps

A vial was charged (S)-2′-amino-3-bromo-5′H-spiro[chromeno[2,3-b]pyridine-5,4′-oxazol]-7-ol (282 mg, 0.809 mmol), p-tolylboronic acid (220 mg, 1.618 mmol), potassium carbonate (559 mg, 4.04 mmol), tetrakis(triphenylphosphine)palladium (46.7 mg, 0.040 mmol). The vial was flushed with Ar (g), then Dioxane (4044 μL) and water (2 mL) were added in sequence. The vial was sealed and placed in an 80° C. oil bath for 1 hour. The mixture was partitioned between brine and 10% iPrOH/EtOAc. The layers were separated, and the aq. layer was extracted with EtOAc. The combined organic extracts were dried over sodium sulfate, filtered, and evaporated. The residue was chromatographed on an 80-g Redi-Sep column, eluting with 0-80% of a 90:10:1 mix of DCM/MeOH/NH4OH in DCM to give (S)-2′-amino-3-p-tolyl-5′H-spiro[chromeno[2,3-b]pyridine-5,4′-oxazol]-7-ol as an orange solid.

Provenance & Evidence