Triethylamine → tert-butyl (2S,4R)-4-(2-cyano ethoxy)-2-[(dimethylamino)carbonyl]pyrrolidine-1-carboxylate

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Reaction Steps

To a solution of 3.00 g of the compound obtained in Step 143-2 and 2.01 g of Et3N in CHCl3 (30 ml) was added 1.36 g of methane sulfonyl chloride under ice cooling and the reaction mixture was stirred at room temperature for one hour. To the solution was added a saturated aqueous solution of NaHCO3 and the resulting mixture was extracted with EtOAc; the organic layer was washed with saturated brine and dried over Na2SO4, then, the drying agent was separated by filtration and the solvent was evaporated under reduced pressure. To a solution of the obtained residue in MeCN (40 ml) was added 2.58 g potassium cyanide and 260 mg of 18-crown-6-ether, and the reaction mixture was refluxed for two hours. To the solution was added water and the resulting mixture was extracted with EtOAc; the organic layer was washed with saturated brine and dried over Na2SO4, then, the drying agent was separated by filtration and the solvent was evaporated under reduced pressure. The obtained residue was purified by column chromatography (silicagel 60N; mobile phase: EtOAc) obtained 1.22 g of the title compound.

Provenance & Evidence