1-Hydroxybenzotriazole → (4-[2-((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}-propionylamino)-ethyl]-phenyl]-acetic acid t-butyl ester

Participants

Reaction Steps

The title C compound, (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 (83.4 mg, 0.137 mmol) is dissolved in DMF (2 mL) and a solution of [4-(2-amino-ethyl)phenyl]-acetic acid t-butyl ester (32.2 mg, 0.137 mmol) in CH2Cl2 (0.5 mL) is added followed by a solution of HOBt (21.9 mg, 0.143 mmol) in DMF:CH2Cl2 (50:50, 0.5 mL), and finally EDCl (27.6 mg, 0.143 mmol) and TEA (0.020 mL, 0.143 mmol) as a slurry in CH2Cl2 (0.5 mL). The reaction is mixed well to give a homogeneous solution. After 3 h, EtOAc (100 mL) is added and the reaction is washed three times with 2N aqueous HCl (50 mL) and saturated aqueous NaHCO3 (50 mL). EtOAc layer is dried over anhydrous Na2SO4 and concentrated to yield {4-[2-((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}-propionylamino)-ethyl]-phenyl}-acetic acid t-butyl ester as an oil.

Provenance & Evidence