4-Methylmorpholine → N-{[4-((2R,3R)-1-(4-chlorophenyl)-3-{[2-(4-chlorophenyl)-2-oxoethyl]thio}-4-oxoazetidin-2-yl)phenoxy]acetyl}glycine

Participants

Reaction Steps

[4-((2R,3R)-1-(4-Chlorophenyl)-3-{[2-(4-chlorophenyl)-2-oxoethyl]thio}-4-oxoazetidin-2-yl)phenoxy]acetic acid, 302.1 mg, 0.585 mmol) was dissolved in DCM (6 ml). N-Methylmorpholine (190 μl, 1.728 mmol) and tert-butyl glycinate hydrochloride (133.4 mg, 0.80 mmol) were added. After 10 minutes, TBTU (224.3 mg, 0.67 mmol) was added and the reaction mixture was stirred for 60 h. The intermediate tert-butylester of the title compound was confirmed. M/z: 626.88 (M−H). DCM (10 ml) and water (15 ml) were added and the mixture was acidified to pH of 3 using KHSO4 (2M). The organic phase was washed with water (2×15 ml). The combined aqueous phases were extracted with DCM (10 ml), dried over Na2SO4, filtered and concentrated. A solution of the residue (500 mg) in DCM (10 ml) and TFA (4 ml) was stirred overnight. The solvent was removed under reduced pressure. Toluene was added and evaporated to assist the removal of TFA. The residue was purified with preparative HPLC on a C8 column. A gradient from 20 to 50% MeCN in 0.1M ammonium acetate buffer was used as eluent. After lyophilisation, the title compound was obtained as a white solid (166.9 mg, 50%). H-NMR (400 MHz, DMS-d6): 3.51 (d, 2H), 4.33 (d, 1H), 4.34 (s, 1H), 4.36 (s, 1H), 4.47 (s, 2H), 5.17 (d, 1H), 6.96 (d, 2H), 7.16-7.21 (m, 2H), 7.35 (d, 4H), 7.54-7.59 (m, 2H), 7.83-7.90 (brs, 1H), 7.91-7.95 (m, 2H). M/z: 571.04 (M−H) and 572.88 (M+H).

Provenance & Evidence