Hydrochloric Acid → n-[(1r)-1-[(4-Chlorophenyl)methyl]-2-(4-{2-[methyl-(methylsulfonyl)amino]phenyl}piperazinyl)-2-oxoethyl]-(tert-butoxy)carboxamide

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Reaction Steps

tert-Butyl 4-{2-[methyl(methylsulfonyl)amino]phenyl}piperazinecarboxylate (Step 1) (700 mg, 1.9 mmol) was stirred with 25 mL of HCl satd EtOAc. The resulting crude material was diluted with EtOAc and washed with a satd NaHCO3 soln. The organic layer was separated, dried over Na2SO4, filtered and concentrated in vacuo. This material was treated with DIEA (400 μl, 2.295 mmol), Boc-p-Cl-D-Phe-OH (672 mg, 2.241 mmol), 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide methiodide (1.25 g, 4.206 mmol), HOAT (345 mg, 2.535 mmol), and DMF (15 mL) according to the procedure for preparation XIX. The crude material was purified by flash chromatography (SiO2, 1.5:1 hexane:EtOAc) to yield N-[(1R)-1-[(4-chlorophenyl)methyl]-2-(4-{2-[methyl-(methylsulfonyl)amino]phenyl}piperazinyl)-2-oxoethyl]-(tert-butoxy)carboxamide (327 mg). MS (ESI, pos. ion) m/z: 551 (M+H), (ESI, neg. ion) m/z: 549 (M−H). Calc'd for C26H35ClN4O5S: 551.10.

Provenance & Evidence