(S)-3-(tert-Butoxycarbonyl(isopropyl)amino)-2-(4-chlorophenyl)propanoic acid (87 mg, 0.25 mmol, see Example H), N1-((ethylimino)methylene)-N3,N3-dimethylpropane-1,3-diamine hydrochloride (65 mg, 0.34 mmol), HOBt-H2O (52 mg, 0.34 mmol) and triethylamine (51 mg, 0.51 mmol) were added to 5-(4-fluorophenyl)-4-(piperazin-1-yl)-1H-pyrrolo[2,3-b]pyridine (50 mg, 0.17 mmol) in DCM (10 mL). The reaction was stirred for 18 hours. The reaction was then diluted with DCM (50 mL) and washed with 1N HCl, 10% K2CO3 and brine. After drying with MgSO4 and concentration, the resulting residue was purified by chromatography (SP4, 12+M, water/ACN 80/20→0/100, 20CV) to yield (S)-tert-butyl 2-(4-chlorophenyl)-3-(4-(5-(4-fluorophenyl)-1H-pyrrolo[2,3-b]pyridin-4-yl)piperazin-1-yl)-3-oxopropyl(isopropyl)carbamate (42 mg, 40% yield) as a solid.
