Triethylamine → di-tert-butyl (4S)-N-(tert-butoxycarbonyl)-4-[3-tert-butoxy-4-(2-fluoroethoxy)benzyl]-L-glutamate

Participants

Reaction Steps

To a stirred solution of 64 mg (0.11 mmol) di-tert-butyl (4S)—N-(tert-butoxycarbonyl)-4-[3-tert-butoxy-4-(2-hydroxyethoxy)benzyl]-L-glutamate in 0.5 ml THF was added 102.7 mg (0.34 mmol) nonafluoro 1-butanesulphonic acid fluoride, 54.8 mg (0.34 mmol) triethylamine trihydrofluoride and 102 mg (1.01 mmol) triethyl amine. The reaction mixture is stirred for 3 days. Further 34 mg (0.11 mmol) nonafluoro 1-butanesulphonic acid fluoride, 18 mg (0.11 mmol) triethylamine trihydrofluoride and 34 mg (0.33 mmol) triethyl amine were added. The reaction mixture is stirred for 3 hours and is concentrated in vacuo. The crude product is purified by column chromatography (silica gel, hexane/ethylacetate gradient: 12:1→1:1). The desired product was obtained in 37.4% yield (64.2 mg, 0.04 mmol).

Provenance & Evidence