N-Acetyl-L-phenylalanine → (S)-2-((S)-2-acetylamino-3-phenyl-propionylamino)-3-(4-[5-(4-methoxy-benzyl)-1,1,4-trioxo-1,2,5-thiadiazolidin-2-yl]-phenyl)-propionic acid benzyl ester

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Reaction Steps

The title A compound, (S)-2-amino-3-{4-[5-(4-methoxy-benzyl)-1,1,4-trioxo-1,2,5-thiadiazolidin-2-yl]-phenyl}-propionic acid benzyl ester (79 mg, 0.155 mmol) and (S)-2-acetylamino-3-phenyl-propionic acid (33.7 mg, 0.162 mmol) are dissolved in CH2Cl2 (3.1 mL). HOBt (24.8 mg, 0.162 mmol) is added as a solid, followed by EDCl (31.0 mg, 0.162 mmol) and TEA (0.023 mL, 0.162 mmol) in a slurry of CH2Cl2 (1 mL). After 1 h, EtOAc (100 mL) is added and the mixture is washed three times with 2N aqueous HCl (50 mL) followed by saturated aqueous NaHCO3 (50 mL). The EtOAc layer is dried over anhydrous Na2SO4 and concentrated to yield (S)-2-((S)-2-acetylamino-3-phenyl-propionylamino)-3-{4-[5-(4-methoxy-benzyl)-1,1,4-trioxo-1,2,5-thiadiazolidin-2-yl]-phenyl}-propionic acid benzyl ester as a white powder.

Provenance & Evidence