Tetrahydrofuran → (5S)-3-bromo-7-(3-pyridinyl)spiro[chromeno[2,3-b]pyridine-5,4'-[1,3]oxazol]-2'-amine

Participants

Reaction Conditions

Reaction Steps

A sealable tube was charged with (5S)-7-iodo-3-bromo-spiro[chromeno[2,3-b]pyridine-5,4′-[1,3]oxazol]-2′-amine (350 mg, 0.764 mmol), pyridin-3-ylboronic acid (94 mg, 0.764 mmol), tetrakis(triphenylphosphine)palladium (20.04 mg, 0.076 mmol) and THF (7641 μL, 0.764 mmol). The mixture was purged with Ar for 2 minutes then a solution of potassium carbonate (1.5 M) (1019 μL, 1.528 mmol) was added and the reaction vessel was sealed and heated at 110° C. for 6 hours. The reaction was diluted with water (100 mL) and poured into a separatory funnel containing ethyl acetate (50 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-bromo-7-(3-pyridinyl)spiro[chromeno[2,3-b]pyridine-5,4′-[1,3]oxazol]-2′-amine (175 mg, 0.428 mmol, 56.0% yield) as a brown foam. MS m/z=409.0 [M+H]+. Calc'd for C19H14BrN4O2: 409.0.

Provenance & Evidence