Diisopropylethylamine → (2S,4S)-1-tert-butyl 2-(2-oxo-2-(8-oxo-8,9,10,11-tetrahydro-5H-dibenzo[c,g]chromen-3-yl)ethyl) 4-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 (647 mg, 1.74 mmol) in MeCN (20 mL) was added ((2S,4S)-1-(tert-butoxycarbonyl)-4-methylpyrrolidine-2-carboxylic acid (559 mg, 2.44 mmol) and DIPEA (0.36 mL, 2.09 mmol) and the solution was heated to 60° C. After stirring for 3 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,4S)-1-tert-butyl 2-(2-oxo-2-(8-oxo-8,9,10,11-tetrahydro-5H-dibenzo[c,g]chromen-3-yl)ethyl) 4-methylpyrrolidine-1,2-dicarboxylate (621 mg, 69%).

Provenance & Evidence