Dimethylformamide → (S)-3-(3,3-dimethylbut-1-ynyl)-7-(pyridin-3-yl)-5'H-spiro[chromeno[2,3-b]pyridine-5,4'-oxazol]-2'-amine

Participants

Reaction Conditions

Reaction Steps

(5S)-3-Bromo-7-(3-pyridinyl)spiro[chromeno[2,3-b]pyridine-5,4′-[1,3]oxazol]-2′-amine (170 mg, 0.415 mmol), diisopropyl amine (2911 μL, 20.77 mmol), copper iodide (15.82 mg, 0.083 mmol), tetrakis(triphenylphosphine)palladium (48.0 mg, 0.042 mmol), 3,3-dimethylbut-1-yne (171 mg, 2.082 mmol) and DMF (2769 μL, 0.415 mmol) were combined in a sealable tube, which was then flushed with argon and heated at 90° C. for 5 hours. After cooling to room temperature the reaction in the tube was diluted with water (25 mL) and poured into a separatory funnel containing ethyl acetate (25 mL). The layers were separated and the aqueous layer was extracted with ethyl acetate (4×50 mL). The combined organic layers were washed with brine, dried over sodium sulfate, filtered and concentrated in vacuo to provide a brown oil that was purified by silica gel chromatography (Redi-Sep pre-packed silica gel column (40 g), 0-10% methanol in methylenechloride with 0.1% ammonium hydroxide) to provide (5S)-3-(3,3-dimethyl-1-butyn-1-yl)-7-(3-pyridinyl)spiro[chromeno[2,3-b]pyridine-5,4′-[1,3]oxazol]-2′-amine (110 mg, 0.268 mmol, 64.5% yield) as a brown foam. MS m/z=411.2 [M+H]+. Calc'd for C25H23N4O3: 411.2.

Provenance & Evidence