Tetrahydrofuran → tert-butyl (2S)-8-bromo-2-methyl-2,3-dihydrothieno[2,3-f][1,4]oxazepine-4(5H)-carboxylate

Participants

Reaction Steps

To a solution of tert-butyl [(2S)-2-{[4-bromo-2-(hydroxymethyl)thiophen-3-yl]oxy}propyl]carbamate (1.83 g), methanesulfonyl chloride (0.58 ml,) and THF (50 mL) was added 1,8-diazabicyclo[5.4.0]undec-7-ene (1.65 ml,), and the mixture was stirred at room temperature for 2 hr. Water was added to the reaction solution, and the mixture was extracted with ethyl acetate. The extract was washed with water and saturated brine, and dried over magnesium sulfate, and the solvent was evaporated under reduced pressure. To a solution (30 mL) of the residue in DMF was added sodium hydride (60% in oil, 0.4 g) at room temperature, and the mixture was stirred for 30 min. To the reaction mixture was added saturated aqueous ammonium chloride solution, and the mixture was extracted with ethyl acetate. The extract was washed with water and saturated brine, and dried over magnesium sulfate, and the solvent was evaporated under reduced pressure. The residue was purified by silica gel column chromatography (solvent gradient; 5→20% ethyl acetate/hexane) to give the title compound (1.17 g, 67%) as a colorless oil.

Provenance & Evidence