4-Methylmorpholine → ethyl 1(R)-[1-[2(S)-(tert-butoxycarbonylamino)-3-[N-cyclopropyl-N-(pent-4-enyl)amino]propanoyl]-4(R)-hydroxypyrrolidine-2(S)-carboxamido]-2(S)-vinylcyclopropanecarboxylate

Participants

Reaction Steps

A solution of 2(S)-(tert-butoxycarbonylamino)-3-[N-cyclopropyl-N-(pent-4-enyl)amino]propanoic acid (1.47 g, 4.71 mmoL) in 20 mL of DCM was treated sequentially with ethyl 1(R)-[4(R)-hydroxypyrrolidine-2(S)-carboxamido]-2(S)-vinylcyclopropanecarboxylate hydrochloride (prepared in example 5) (1.44 g, 4.71 mmoL), N-methyl morpholine (1.80 mL, 16.34 mmoL), and HATU (2.14 g, 5.53 mmoL). The reaction mixture was stirred at rt under N2 for 3 h, and then concentrated in vacuo. The residue was dissolved in water and 1N HCl was added until the pH=5. This aqueous solution was extracted with EtOAc (3×). The organic phase was washed with sat. aq. NaHCO3, dried (MgSO4), and concentrated in vacuo to give the crude product. Flash chromatography (50% ethyl acetate/hexane to 100% ethyl acetate) gave 1.55 g (58%) of ethyl 1(R)-[1-[2(S)-(tert-butoxycarbonylamino)-3-[N-cyclopropyl-N-(pent-4-enyl)amino]propanoyl]-4(R)-hydroxypyrrolidine-2(S)-carboxamido]-2(S)-vinylcyclopropanecarboxylate as a white foam:

Provenance & Evidence