Cesium carbonate → HCID 58428457, compound

Participants

Reaction Conditions

Reaction Steps

A solution (0.35M) of the product of step 2 in NMP was treated with Cs2CO3 (1.5 eq) and 1-tert-butyl 2-methyl (2S,4S)-4-{[(4-bromophenyl)sulfonyl]oxy}pyrrolidine-1,2-dicarboxylate (1.1 eq). The resulting mixture was stirred at 50° C. for 18 hours, then a further portion (0.1 eq) of 1-tert-butyl 2-methyl (2S,4S)-4-{[(4-bromophenyl)sulfonyl]oxy}pyrrolidine-1,2-dicarboxylate was added. After stirring for 2 hours, the mixture was cooled and diluted with H2O and EtOAc. The organic phases were washed with aqueous HCl (1 N), saturated aqueous NaHCO3 and brine. The dried organic phase was concentrated to a residue that was purified by flash-chromatography (0-60% EtOAc/petroleum ether) to give the title compound (35% for two steps) as a solid. MS (ES−) m/z 438 (M+H)+

Provenance & Evidence