(2S)-[[N-(tert-Butoxycarbonyl)-N-methyl-L-alanyl]amino](cyclohexyl)ethanoic acid → tert-Butyl methylcarbamate

Participants

Reaction Conditions

Reaction Steps

To a solution of 4-fluoro-phenyl)-((S)-5-pyrrolidin-2-yl-pyridin-3-yl)-methanone (2.57 g, 9.5 mmole) and (S)-[(S)-2-(tert-butoxycarbonyl-methyl-amino)-propionylamino]-cyclohexyl-acetic acid (5) (3.58 g, 10.5 mmole) in 75 mL of THF at 0° C., is added 4-(4,6-dimethoxy-[1,3,5]triazin-2-yl)-4-methyl-morpholinium chloride hydrate (2.97 g, 10.7 mmole) in one portion. After stirring at 20° C. for 2 hours, the reaction mixture is diluted with 100 mL of EtOAc, and washed with 3×20 mL of water. After concentration, the crude product is purified by flash column chromatography (CH2Cl2 95%, MeOH 5%) to give (S)-1-((S)-1-cyclohexyl-2-{(S)-2-[5-(4-fluoro-benzoyl)-pyridin-3-yl]pyrrolidin-1-yl}-2-oxo-ethylcarbamoyl)-ethyl]-methyl-carbamic acid tert-butyl ester (6) (5.0 g, yield 88%) as pale yellow solid.

Provenance & Evidence