Dimethylformamide → (S)-4-(2'-amino-7-(cyclopropylethynyl)-5'H-spiro[chromeno[2,3-b]pyridine-5,4'-oxazole]-3-yl)-2-methylbut-3-yn-2-ol

Participants

Reaction Conditions

Reaction Steps

A 0.5-2 mL vial was charged with (S)-2′-amino-3-(3-hydroxy-3-methylbut-1-ynyl)-5′H-spiro[chromeno[2,3-b]pyridine-5,4′-oxazole]-7-yl 1,1,2,2,3,3,4,4,4-nonafluorobutane-1-sulfonate (106 mg, 0.167 mmol), and copper(i) iodide (3.19 mg, 0.017 mmol). The vial was flushed with Ar (g), then DMF (669 μL, 0.167 mmol), diisopropylamine (469 μL, 3.35 mmol), and ethynylcyclopropane (70.8 μL, 0.836 mmol) were added in sequence to give a yellow solution. The vial was sealed and heated overnight in at 80° C. The mixture was diluted with water (15 mL) and extracted with EtOAc (3×10 mL). The combined organic extracts were washed with brine, dried over sodium sulfate, filtered, and evaporated. The residue was purified by chromatography on a 40-g Redi-Sep column, eluting with 0-50% of a 90:10:1 mixture of DCM/MeOH/NH4OH in DCM to give (S)-4-(2′-amino-7-(cyclopropylethynyl)-5′H-spiro[chromeno[2,3-b]pyridine-5,4′-oxazole]-3-yl)-2-methylbut-3-yn-2-ol as a tan solid after evaporation from DCM/hexanes.

Provenance & Evidence