Ammonium Chloride → HCID 117736314, compound

Participants

Reaction Steps

tert-Butyl 2-bromoacetate (2.09 ml, 14.2 mmol) was added to a solution of (S)-2-((((9H-fluoren-9-yl)methoxy)carbonyl)amino)-3-(1-(tert-butoxycarbonyl)-1H-indol-3-yl)propanoic acid (Fmoc-Trp(Boc)-OH) (Compound SP613) (5.0 g, 9.50 mmol) and diisopropylethylamine (DIPEA) (4.98 ml, 28.5 mmol) in dichloromethane (DCM) (9.5 ml) at room temperature under a nitrogen atmosphere, and the mixture was stirred at the same temperature for 48 hours. An aqueous ammonium chloride solution was added to the reaction solution, the mixture was extracted with dichloromethane (DCM) twice, and the organic layer was washed with brine twice. The organic layer was dried over sodium sulfate, and then filtered and concentrated under reduced pressure. The resulting residue was purified by normal-phase silica gel chromatography (hexane/ethyl acetate) to afford (S)-tert-butyl 3-(2-((((9H-fluoren-9-yl)methoxy)carbonyl)amino)-3-(2-(tert-butoxy)-2-oxoethoxy)-3-oxopropyl)-1H-indole-1-carboxylate (Fmoc-Trp(Boc)-HoGly-OtBu) (Compound SP614) as a mixture (5.25 g).

Provenance & Evidence