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

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of {4-[(2R,3R)-3-{[2-(1,3-benzodioxol-5-yl)-2-oxoethyl]thio}-1-(4-chlorophenyl)-4-oxoazetidin-2-yl]phenoxy}acetic acid (35.4 mg, 0.067 mmol)) in DMF (3 ml) was added N-methylmorpholine (35 μl, 0.23 mmol). TBTU (29.3 mg, 0.091 mmol) was added and the reaction mixture was stirred at 30° C. for 1 hour. Glycyl-3-cyclohexyl-D-alanine (18.4 mg, 0.081 mmol) was added and the mixture was stirred at ambient temperature for 60 hours. The formation of the ketone of the title compound was confirmed. M/z: 736.67 (M+1) and 734.71 (M−1). Without further purification, methanol (2 ml) and sodium borohydride (28.0 mg, 0.740 mmol) was added and the mixture was stirred for 20 minutes. Ammonium acetate (38.4 mg) was added and the solution 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 pure fractions were collected and the MeCN was removed under reduced pressure. The remaining water solution was acidified to pH 1 with HCl (1M) and extracted with DCM. The organic phase was passed through a phase separator and concentrated under reduced pressure. The residue was dissolved in MeCN and water. After lyophilisation, the title compound was obtained 1H-NMR (400 MHz, DMSO-d6): 0.70-1.68 (m, 13H), 2.78-2.88 (m, 2H), 3.75 (d, 2H), 4.13-4.21 (m, 1H), 4.23-4.28 (m, 1H), 4.49 (s, 2H), 4.56-4.64 (m, 1H), 5.02 (d, 0.5H), 5.04 (d, 0.5H), 5.56 (b, 1H), 6.70-6.79 (m, 2H), 6.82 (s, 1H), 6.96 (d, 2H), 7.18 (d, 2H), 7.30-7.37 (m, 4H), 8.04 (b, 1H), 8.20 (t, 1H). M/z: 736.69 (M−1).

Provenance & Evidence