Diisopropylethylamine → (S)-6-Hydroxy-2-{(S)-2-[(S)-3-(4-hydroxy-phenyl)-2-methyl-propionylamino]-4-methyl-pentanoylamino}-hexanoic acid methyl ester

Participants

Reaction Steps

To a suspension of (S)-2-[(S)-2-benzyloxycarbonylamino-3-(4-hydroxy-phenyl)-propionyl-amino]-4-methyl pentanoic acid (Bachem) (5.44 mmol, 1.36 g, 1 eq) and methyl ester 82 (5.44 mmol, 0.91 g) in DMF was added HATU (5.98 mmol, 1.41 g, 1.1 eq). DIPEA (0.12 mol, 1.62 g, 2.1 eq) was added and the reaction mixture was stirred at room temperature overnight. EtOAc (100 mL) was added the mixture was washed with 1M hydrochloric acid, saturated aqueous NaHCO3 and brine. The organic layer was dried over MgSO4 and the solvent was removed in vacuo. The crude product was purified by recrystallisation from EtOAc to provide diol 83 as an oil (2.39 g, 76%).

Provenance & Evidence