Ethyl Acetate → 9H-fluoren-9-ylmethyl-6-[1-(tert-butoxycarbonyl)-1H-pyrrol-2-yl]-2,4,4-trimethyl-2H-3,1-benzoxazine-1(4H)-carboxylate

Participants

Reaction Steps

A mixture of tert-butyl-5-(2,4,4-trimethyl-1,4-dihydro-2H-3,1-benzoxazin-6-yl)-1H-pyrrole-1-carboxylate (1.7 g, 4.96 mmol), 9-fluorenylmethyl chloroformate (1.92 g, 7.5 mL), sodium carbonate (4 g, 37 mmol) in dioxane (50 mL) and water (50 mL) was stirred at room temperature under a blanket of nitrogen for 6 hours. Ethyl acetate (100 mL) was added and organic layer was separated, dried (MgSO4), and evaporated. The residue was purified by a silica gel column chromatography (hexane:ethyl acetate/6:1) to afford 9H-fluoren-9-ylmethyl-6-[1-(tert-butoxycarbonyl)-1H-pyrrol-2-yl]-2,4,4-trimethyl-2H-3,1-benzoxazine-1 (4H)-carboxylate as a clean oil.

Provenance & Evidence