Ethyl Acetate → (betaS)-N-(tert-Butoxycarbonyl)-4-fluoro-beta-methyl-L-phenylalanyl-L-prolinamide

Participants

Reaction Steps

To a stirred solution of (2S,3S)-2-azido-3-(4-fluorophenyl)butanoic acid Example 1, Step D, 91.8 mg, 0.309 mmol) in anhydrous N,N-dimethylformamide (DMF, 1.5 mL) was added [O-(7-azabenzotriazol-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate) (HATU, 141 mg, 0.371 mmol), 1-hydroxy-7-azabenzotriazole (HOAT, 50.5 mg, 0.371 mmol), L-prolinamide (38.8 mg, 0.340 mmol) and N,N′-diisopropylethylamine (0.135 mL, 0.773 mmol). After stirring at room temperature for 16 h, the reaction was diluted with ethyl acetate. The organic phase was washed sequentially with water, saturated aqueous sodium bicarbonate solution and brine, dried (magnesium sulfate), and concentrated under reduced pressure. The residue was purified by preparative thin layer chromatography (silica, ethyl acetate eluant) to afford the title compound.

Provenance & Evidence