Diisopropylethylamine → HCID 131736677, compound

Participants

Reaction Conditions

Reaction Steps

DMA, 1.05 equivalents of DIPEA (Mw=129.2) and 1.05 equivalents of H-Trp-Pro-OH (Mw=301.3; purity=91.0%) were mixed at room temperature for at least 30 min until a solution had formed. The reaction mixture was then diluted with ethyl acetate and cooled to 5±5° C. Once this temperature was reached, 1.00 equivalent of Z-Trp-OSu (Mw=435.45; purity=98.0%) was added and stirring continued for at least 30 min before the solution was left to warm up to room temperature again. After the completion of the reaction was confirmed by HPLC, 0.2 eq of, DMAPA (N,N′-Dimethylaminopropylamine, Mw=102.2 g/mol) were added. The reaction mixture was diluted with ethyl acetate and washed with a 5% (weight) aqueous NaCl solution containing 2 equivalents of KHSO4. The organic phase was further washed first with a 5% (weight) aqueous NaCl solution and finally with water. The organic phase was partially concentrated in vacuo and the residue was suspended in ethyl acetate and further concentrated in order to eliminate the remaining water. The concentrated peptide solution was added in small portions to a cold (0±5° C.) mixture of MTBE/petroleum ether (45-55) (1/1) and the precipitate was kept at 0±5° C. for at least 30 min before filtration. After filtration, it was then washed with petroleum ether (45-55) and dried in vacuo at 45° C. A white solid was finally obtained.

Provenance & Evidence