Sodium Chloride → Boc-Phe-Gly-Val-Gly-OBzl

Participants

Reaction Conditions

Reaction Steps

Boc-Phe-OH (9.16 g, 34.54 mmol) was dissolved in 100 ml of dimethylformamide (DMF), cooled to 0° C. and N-methylmorpholine (NMM) (3.83 ml) added. The solution was cooled to -15° C. and isobutyl chloroformate (IBCF) (3.96 ml, 30 mmol) was added slowly under stirring while maintaining the temperature at -15°±1° C. After stirring at this temperature for 15 minutes, a precooled solution of II (9.4 g, 21.59 mmol) and NMM (2.4 ml) in DMF (40 ml) was added and stirring continued for two hours at ice-bath temperature. A saturated solution of KHCO3 was added to bring the pH to 8.0 and stirred for an additional 30 minutes. The reaction mixture was poured into a cold 90% saturated NaCl solution (1000 ml) and the precipitate obtained was filtered, washed with satd. NaCl, H2O and dried. The peptide was crystallized from ethyl acetate to give 10 g of III (yield: 81.5%). Rf2 0.83 Anal. Calcd. for C30H40N4O7 : C 63.35, H 7.09, N 9.85%. Found: C 62.96, H 7.37, N 9.86%.

Provenance & Evidence