N,beta,beta-trimethyl-L-phenylalanyl-N1-[(1S,2E)-3-(ethoxysulfonyl)-1-isopropylprop-2-enyl]-N1,3-dimethyl-L-valinamide → N,beta,beta-trimethyl-L-phenylalanyl-N1-[(1S,2E)-1-isopropyl-3-sulfoprop-2-enyl]-N1,3-dimethyl-L-valinamide

Participants

Reaction Steps

A solution of N,β,β-trimethyl-L-phenylalanyl-N1-[(1S,2E)-3-(ethoxysulfonyl)-1-isopropylprop-2-enyl]-N1,3-dimethyl-L-valinamide (30 mg, 0.057 mmol) from Example 63 in acetone (1 mL) is treated with tetrabutylammonium iodide (21 mg, 0.057 mmol). The reaction mixture is refluxed for 9 h, and then stirred at room temperature overnight. The solvent is removed. The residue is purified by reversal phase HPLC (mobile phase A: 0.1% TFA/5% acetonitrile/H2O, mobile phase B: 100% acetonitrile) to give 10 mg (28%) of the title compound as a white solid. HRMS (ESI) calcd for C25H41N3O5S [M+H] 496.2840, found 498.2840.

Provenance & Evidence