Methanol → HCID 71278867, compound

Participants

Reaction Conditions

Reaction Steps

A solution of tert-butyl 4-[1-(6-hydroxy-3-oxo-2,3-dihydrobenzofuran-7-yl)ethyl]piperazine-1-carboxylate (0.75 g, 2.1 mmol) synthesized in Example B7, Step 2 in tetrahydrofuran (20 mL) was added with methanol (0.20 g, 6.3 mmol), and triphenylphosphine (0.65 g, 2.5 mmol). The reaction mixture was stirred at 0° C. under an argon atmosphere, and added dropwise with a 40% solution of diethyl azodicarboxylate in toluene (1.91 g, 4.4 mmol). After completion of the addition, the mixture was stirred at 40° C. for 20 hours. The solvent was evaporated under reduced pressure, and the residue was subjected to silica gel column chromatography (eluted with hexane/ethyl acetate (85:15→0:100)) to obtain a solid containing the objective substance. The solid was suspended in a mixed solvent of hexane and ethyl acetate and thereby washed, and the insoluble matter was removed by filtration. The filtrate was concentrated, the residue was subjected to silica gel column chromatography (aminopropyl silica was used, eluted with hexane/ethyl acetate (2:1→1:3)) to obtain tert-butyl 4-[1-(6-methoxy-3-oxo-2,3-dihydrobenzofuran-7-yl)ethyl]piperazine-1-carboxylate (0.091 g, 12%).

Provenance & Evidence