Tetrahydrofuran → HCID 68006325, compound

Participants

Reaction Steps

A mixture of the compound of Reference Example 2 (4.05 g, 19.5 mmol), ethyl (chloroformyl)acetate (3.71 mL, 29.3 mmol), triethylamine (5.40 mL, 39.0 mmol) and THF (41 mL) was stirred at room temperature for 4 hr. To the reaction mixture was added saturated aqueous sodium hydrogen carbonate solution (100 mL), and the mixture was extracted with ethyl acetate (200 mL). The extract was washed with brine (100 mL), and dried over anhydrous sodium sulfate. The insoluble material was removed by filtration, and the filtrate was concentrated under reduced pressure. To the residue were added ethanol (188 ml) and 20% ethanol solution (13.3 mL, 39.0 mmol) of sodium ethoxide, and the mixture was stirred at 50° C. for 3 hr. The reaction mixture was concentrated under reduced pressure, and to the residue was added 1N hydrochloric acid (100 mL), and the mixture was extracted with ethyl acetate (200 mL). The extract was washed with brine (100 and dried over anhydrous sodium sulfate. The insoluble material was removed by filtration, the filtrate was concentrated under reduced pressure, and the residue was purified by silica gel column chromatography (eluate, hexane:ethyl acetate=98:2→70:30) to give the title compound (3.15 g, 56%) as a yellow oil.

Provenance & Evidence