4-Methylmorpholine → N-({4-[(2R,3R)-3-{[2-(1,3-benzodioxol-5-yl)-2-hydroxyethyl]thio}-1-(4-fluorophenyl)-4-oxoazetidin-2-yl]phenoxy}acetyl)glycyl-D-lysine

Participants

Reaction Steps

To a stirred solution of N-({4-[(2R,3R)-3-{[2-(1,3-benzodioxol-5-yl)-2-hydroxyethyl]thio}-1-(4-fluorophenyl)-4-oxoazetidin-2-yl]phenoxy}acetyl)glycine (11.3 mg, 0.020 mmol) in DCM (2 ml) were added tert-butyl N6-(tert-butoxycarbonyl)-D-lysinate hydrochloride (9.5 mg, 0.028 mmol), N-methylmorpholine (15 μl, 0.091 mmol) and TBTU (11.0 mg, 0.034 mmol). The reaction mixture was stirred at ambient temperature for 3 hours. The formation of the intermediate tert-butyl N-({4-[(2R,3R)-3-{[2-(1,3-benzodioxol-5-yl)-2-hydroxyethyl]thio}-1-(4-fluorophenyl)-4-oxoazetidin-2-yl]phenoxy}acetyl)glycyl-N6-(tert-butoxycarbonyl)-D-lysinate was confirmed. M/z: 852.23 (M−1). The solvent was removed under reduced pressure and the residue was dissolved in formic acid (2 ml). The mixture was stirred at ambient temperature for 48 hours. The solvent was co-evaporated with toluene and the residue was purified with preparative HPLC on a C8 column, UV 240/260 nm. A gradient from 20 to 45% MeCN in 0.1M NH4OAc buffer was used as eluent. The MeCN was removed under reduced pressure and the residue was lyophilised to give the title. H-NMR (400 MHz, DMSO-d6): 1.08-1.32 (m, 2H), 1.37-65 (m, 4H), 2.63 (t, 2H), 2.77-2.92 (m, 2H), 3.70 (d, 2H), 3.76-3.82 (m, 1H), 4.25 (d, 0.5H), 4.28 (d, 0.5H), 4.50 (s, 2H), 4.57-4.64 (m, 1H), 5.00 (d, 0.5H), 5.02 (d, 0.5H), 5.90-5.94 (m, 2H), 6.70-6.81 (m, 2H), 6.83 (s, 1H), 6.96 (d, 2H), 7.08-7.16 (m, 2H), 7.17-7.24 (m, 2H), 7.34 (d, 2H), 7.45-7.55 (m, 1H), 8.37-8.43 (m, 1H). M/z: 697.32 (M+1) and 695.39 (M−1).

Provenance & Evidence