5-Fluoro-2-nitrophenol → 4-(5-fluoro-2-nitrophenoxy)tetrahydro-2H-pyran

Participants

Reaction Steps

Di-tert-butyl azodicarboxylate (17.6 g, 76.4 mmol) was added into a solution of 5-fluoro-2-nitrophenol (10 g, 63.7 mmol), tetrahydro-2H-pyran-4-ol (7.3 mL, 76.4 mmol) and triphenyl phosphine (20 g, 76.4 mmol) in anhydrous DCM (120 mL) at 0° C. The solution was allowed to warm to ambient temperature overnight, concentrated in vacuo and the crude product triturated with n-pentane/diethyl ether (×2) to remove the triphenyl phosphine oxide (16.5 g) by-product. The sample was purified by flash column chromatography (5:1 petroleum ether (40-60° C.)/EtOAc) to yield yellow oil which was used in the next step directly.

Provenance & Evidence