Lithium Hexamethyldisilazide → (S)-3-(2,2-dimethylmorpholino)-7-(2-fluoropyridin-3-yl)-5'H-spiro[chromeno[2,3-b]pyridine-5,4'-oxazol]-2'-amine

Participants

Reaction Steps

A vial was charged with (S)-3-bromo-7-(2-fluoropyridin-3-yl)-5′H-spiro[chromeno[2,3-b]pyridine-5,4′-oxazol]-2′-amine (110 mg, 0.257 mmol), DavePhos (12.16 mg, 0.031 mmol), and tris(dibenzylideneacetone)dipalladium(0) (11.79 mg, 0.013 mmol). The vessel was flushed with Ar(g), then lithium bis(trimethylsilyl)amide (772 μL, 0.772 mmol) (1.0 M solution in THF) and 2,2-dimethylmorpholine (61.8 μL, 0.515 mmol) were added in sequence. The vial was sealed and placed in a 75° C. oil bath for two hours. The mixture was diluted with saturated aq. ammonium chloride solution (20 mL) and water (10 mL). The mixture was extracted with DCM (3×20 mL), leaving behind a dark oily solid. The combined organic extracts were dried over sodium sulfate, filtered, and evaporated. The residue was chromatographed on an 24-g Redi-Sep Gold column with 0-70% of a 90:10:1 mix of DCM/MeOH/NH4OH in DCM to give (S)-3-(2,2-dimethylmorpholino)-7-(2-fluoropyridin-3-yl)-5′H-spiro[chromeno[2,3-b]pyridine-5,4′-oxazol]-2′-amine as a yellow solid.

Provenance & Evidence