Tributylphosphine → tert-butyl (3R,4S)-3-({cyclopropyl[3-{[(1R,2R)-2-(ethoxy-carbonyl)cyclopropyl]methoxy}-5-(3-methoxypropyl)benzyl]amino}carbonyl)-4-{4-[2-(2,6-dichloro-4-methylphenoxy)ethoxy]phenyl}piperidine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a solution of tert-butyl(3R,4S)-3-({cyclopropyl[3-hydroxy-5-(3-methoxy-propyl)benzyl]amino}carbonyl)-4-{4-[2-(2,6-dichloro-4-methylphenoxy)ethoxy]-phenyl}piperidine-1-carboxylate (1 eq.) from Example 1/Step 2 in toluene (0.1 M) was added 1,1′-(azodicarbonyl)dipiperidine (1.2 eq.), ethyl (1R,2R)-2-(hydroxyl-methyl)cyclopropanecarboxylate (2 eq.) from the previous step, and tri-n-butylphosphine (1.2 eq.). The reaction was heated to 80° C. and stirred for 18 h. While hot, the reaction was diluted with EtOAc/water. The aqueous layer was extracted with EtOAc. The combined organic extracts were washed with brine, dried over MgSO4, and concentrated in vacuo. The crude product was purified by flash column chromatography (SiO2, 40% EtOAc in Hex) to afford the title compound as an oil.

Provenance & Evidence