Potassium Carbonate → (S)-3-(3,6-dihydro-2H-pyran-4-yl)-7-(pyrimidin-5-yl)-5'H-spiro[chromeno[2,3-b]pyridine-5,4'-oxazol]-2'-amine

Participants

Reaction Steps

A 10-20 mL microwave vial was charged with (S)-3-bromo-7-iodo-5′H-spiro[chromeno[2,3-b]pyridine-5,4′-oxazol]-2′-amine (503 mg, 1.098 mmol), pyrimidin-5-ylboronic acid (143 mg, 1.153 mmol), pd(ph3p)4 (127 mg, 0.110 mmol). The vial was flushed with Ar(g), then THF (5489 μL, 1.098 mmol) and potassium carbonate (1.5 M) (1464 μL, 2.195 mmol) (aq. solution) were added in sequence. The vial was sealed and heated at 110° C. for 2 hours. The mixture was diluted with water and extracted with 10% i-PrOH/EtOAc (3×). The combined organic extracts were dried over sodium sulfate, filtered, and evaporated. The residue was purified by chromatography on a 100-g SNAP column, eluting with 0-100% of a 90:10:1 mixture of DCM/MeOH/NH4OH in DCM to provide (S)-3-bromo-7-(pyrimidin-5-yl)-5′H-spiro[chromeno[2,3-b]pyridine-5,4′-oxazol]-2′-amine as an off-white solid. Step 2: A vial was charged with (S)-3-bromo-7-(pyrimidin-5-yl)-5′H-spiro[chromeno[2,3-b]pyridine-5,4′-oxazol]-2′-amine (68.1 mg, 0.166 mmol), 2-(3,6-dihydro-2H-pyran-4-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (105 mg, 0.498 mmol), tetrakis(triphenylphosphine)palladium (19.18 mg, 0.017 mmol), THF (830 μL), and potassium carbonate (415 μL, 0.830 mmol) (as a 2.0 M aq. solution). The vial was sealed and placed in a 110° C. for 5 hours. The layers were separated, and the aqueous layer was extracted with EtOAc (2×). The combined organic extracts were dried over sodium sulfate, filtered, and evaporated. The residue was purified by chromatography on a 25-g SNAP column, eluting with 0-60% of a 90:10:1 mixture of DCM/MeOH/NH4OH in DCM to give (S)-3-(3,6-dihydro-2H-pyran-4-yl)-7-(pyrimidin-5-yl)-5′H-spiro[chromeno[2,3-b]pyridine-5,4′-oxazol]-2′-amine as a white solid

Provenance & Evidence