Triethylamine → (2S,5 S)-1-tert-butyl 2-(2-oxo-2-(8-oxo-8,9,10,11-tetrahydro-5H-dibenzo[c,g]chromen-3-yl)ethyl) 5-methylpyrrolidine-1,2-dicarboxylate

Participants

Reaction Conditions

Reaction Steps

To a solution of 3-(2-bromoacetyl)-10,11-dihydro-5H-dibenzo[c,g]chromen-8(9H)-one in MeCN (30 mL) was added (2S,5S)-1-(tert-butoxycarbonyl)-5-methylpyrrolidine-2-carboxylic acid (1.2 g, 3.23 mmol) and triethyl amine (0.48 mL, 3.55 mmol) and the solution was heated to 50° C. After stirring for 15 h, the solution was cooled to rt, and diluted with EtOAc and washed successively with saturated aqueous NaHCO3 and brine. The organics were dried over MgSO4, filtered and concentrated under reduced pressure. The crude residue was purified by silica column chromatography (20% to 50% EtOAc/hexanes) to afford (2S,5S)-1-tert-butyl 2-(2-oxo-2-(8-oxo-8,9,10,11-tetrahydro-5H-dibenzo[c,g]chromen-3-yl)ethyl) 5-methylpyrrolidine-1,2-dicarboxylate (1.09 g, 65%).

Provenance & Evidence