Potassium Carbonate → (S)-4-(2-tert-Butoxycarbonylamino-2-methoxycarbonylethyl)-3,5-dimethylbenzoic acid

Participants

Reaction Conditions

Reaction Steps

To a suspension of (S)-2-tert-butoxycarbonylamino-3-(2,6-dimethyl-4-trifluoromethanesulfonylphenyl)-propionic acid methyl ester (9.68 g, 21.3 mmol), K2CO3 (14.1 g, 0.102 mol), Pd(OAc)2 (0.48 g, 2.13 mmol) and 1,1′-bis(diphenylphosphino)ferrocene (2.56 g, 4.47 mmol) in DMF (48 mL) was bubbled in gaseous CO for 15 min. The mixture was heated to 60° C. for 8 h with a CO balloon. The cool mixture was partitioned between NaHCO3 and EtOAc, and filtered. The aqueous layer was separated, acidified with 10% citric acid aqueous solution, extracted with EtOAc, and finally dried over Na2SO4. Filtration and concentration of the filtrate resulted in a residue. The residue was recrystallized from EtOAc-hexanes to yield the desired product.

Provenance & Evidence