Diisopropylcarbodiimide → (R)-3-((5-(4-chlorophenyl)-1-ethyl-4-(3-(4-(4-(4-((4-(4-hydroxypiperidin-1-yl)-1-(phenylthio)butan-2-yl)amino)-3-((trifluoromethyl)sulfonyl)phenylsulfonamido)phenyl)piperazin-1-yl)phenyl)-2-methyl-1H-pyrrole-3-carbonyl)oxy)propanoic acid

Participants

Reaction Steps

To a solution of 957 (100 mg, 0.09 mmol), DIC (18 mg, 0.14 mmol) and DMAP (20 mg, 0.14 mmol) in DCM (2 mL) was added tert-butyl 3-hydroxypropanoate (41 mg, 0.28 mmol). The solution was stirred for 6 hours at room temperature until no BM-957 was observed by TLC. The reaction mixture was diluted with ethyl acetate (50 mL), washed with saturated NaHCO3 solution (50 mL), brine (50 mL) and dried over sodium sulfate. The solvent was removed in vacuo to give crude product which was used for next step without purification. The resulting residue was dissolved in DCM (5 mL) and followed by adding TFA (2.5 mL). The solution was stirred at room temperature for 3 h until no starting material was observed by TLC. The reaction mixture was concentrated in vacuo and the residue was purified by HPLC to give the pure product 5 (salt with TFA, 75 mg, yield 70% over two steps). The gradient ran from 60% of solvent A and 40% of solvent B to 20% of solvent A and 80% of solvent B in 40 min. MS (ESI): m/z 1238.17 (M+H)+.

Provenance & Evidence