Triethylamine → Fmoc-Asn(Trt)-OH

Participants

Reaction Steps

3.4 g of 9-fluorenylmethyl N-succinimidyl carbonate (10 mmol) are added and, at the same time, 1.4 ml of triethylamine are added dropwise so that the pH is 8.3-8.7 to a vigorously stirred solution of 3.8 g of H-Asn(Trt)-OH.0.5 H2O (10 mmol) in 20 ml of tetrahydrofuran, 10 ml of water and 1.4 ml of triethylamine (10 mmol). After 20 minutes, the mixture is cooled in an ice bath and ethyl acetate and 25 ml of a one-molar aqueous potassium bisulfate solution are added. The organic phase is washed with water until free of sulfate, dried over sodium sulfate and concentrated under reduced pressure to about 50 g. The Fmoc-Asn(Trt)-OH can be crystallized by slow addition of diisopropyl ether, m.p. 210°-211° (with decomposition).

Provenance & Evidence