Piperidine → HCID 10863399, compound

Participants

Reaction Steps

To a solution of N-fluorenylmethoxycarbonyl-S-trityl-L-cysteine 1,1-dimethylethyl ester (640 mg, 1 mmol) in 5 mL of DMF was added 2 mL of piperidine. The solution was stirred for 20 min., and the solvent was evaporated. The residual piperidine was removed by azeotroping the solid with DMF (3×20 mL) and drying under high vacuum for 1 hour to give S-trityl-L-cysteine 1,1-dimethylethyl ester as a solid. To this solid was added 5 mL of DMF followed by 1-(2-azidoethyl)cyclopentane carboxylic acid (6a) (183 mg, 1 mmol), HBTU (379 mg, 1 mmol), and DIPEA (0.18 mL, 1 mmol). The resulting solution was stirred for 5 hours, and the solvent was removed under high vacuum. The residue was purified by silica gel column chromatography usilng ethylacetate/hexanes (15/85) as eluent, to afford 500 mg (86%) of N-[[1-(2-azidoethyl)cyclopentyl]carbonyl]-S-triphenylmethyl-L-cysteinie 1,1-dimethylethyl ester.

Provenance & Evidence