Tetrahydrofuran → (S)-2-amino-7'-(pyridin-3-yl)-5H-spiro[oxazole-4,9'-xanthen]-2'-ol

Participants

Reaction Conditions

Reaction Steps

A 350-mL pressure vessel was charged with (R)-2-amino-2′-bromo-5H-spiro[oxazole-4,9′-xanthen]-7′-ol (4.00 g, 11.52 mmol), 3-pyridylboronic acid (3.54 g, 28.8 mmol), tetrakis(triphenylphosphine)palladium(0) (1.331 g, 1.152 mmol), THF (57.6 mL), and potassium carbonate (2.0M aq. solution) (28.8 mL, 57.6 mmol). The vessel was sealed and heated to 100° C. and stirred for 2 hours. The layers were partitioned between EtOAc (20 mL) and water (20 mL). The layers were separated, and the aqueous layer was extracted with EtOAc (2×20 mL). The combined organic layers were washed with brine (emulsion!), dried over sodium sulfate and filtered with the aid of 10% MeOH/DCM. The filtrate was evaporated to give a yellow solid. This solid was taken up in minimal DCM and sonicated for 5 min. The solid was filtered and washed with DCM (30 mL). Filtering and washing with DCM afforded (S)-2-amino-7′-(pyridin-3-yl)-5H-spiro[oxazole-4,9′-xanthen]-2′-ol as a pale-yellow solid

Provenance & Evidence