4-Methylmorpholine → n-{[4-((2r,3r)-1-(4-Chlorophenyl)-3-{[2-(4-chlorophenyl)-2-hydroxyethyl]thio}-4-oxoazetidin-2-yl)phenoxy]acetyl}glycyl-d-valine

[4-((2R,3R)-1-(4-Chlorophenyl)-3-{[2-(4-chlorophenyl)-2-oxoethyl]thio}-4-oxoazetidin-2-yl)phenoxy]acetic acid (15.3 mg, 0.03 mmol), N-methylmorpholine (10 μl, 0.091 mmol) and tert-butyl glycyl-D-valinate hydrochloride, (10.4 mg, 0.039 mmol) were dissolved in DCM (2 ml). After 10 minutes, TBTU (11.9 mg, 0.037 mmol) was added and the mixture was stirred overnight. The intermediate tert-butylester was confirmed. M/z: 727.8 (M−H). The reaction mixture was extracted between water (10 ml, acidified to pH of 3 with KHSO4 (2M)) and DCM (3×10 ml). The combined organic phases were washed with water (2×20 ml), dried over Na2SO4, filtered and concentrated. The oily residue was dissolved in DCM (2 ml) and TFA (1.3 ml) was added. The mixture was stirred overnight. The solvent was evaporated and co-evaporation with toluene was performed to assist the removal of TFA. The residue was dissolved in methanol (2 ml) and sodium borohydride (12.3 mg, 0.33 mmol) was added. After 15 minutes, ammonium acetate (17 mg) was added and the solvent was removed under reduced pressure. The residue was purified on preparative HPLC on 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 (15.1 mg, 77%). H-NMR (400 MHz, DMSO-d6): 0.78 (d, 3H), 0.80 (d, 3H), 0.95-1.03 (m, 1H), 2.83-3.00 (m, 2H), 3.75-3.80 (m, 2H), 3.93-4-00 (t, 1H), 4.30 (d, 0.5H), 4.36-4.38 (brs, 0.5H), 4.52 (s, 2H), 4.69-4.77 (m, 1H), 5.02 (d, 0.5H), 5.06 (d, 0.5H), 6.96-7.00 (m, 2H), 7.18-7.22 (m, 2H), 7.31-7.38 (m, 8H), 7.60-7.74 (m, 1H), 8.28 (t, 1H). M/z: 671.9 (M+H).

1. extractionThe reaction mixture was extracted between water (10 ml, acidified to pH of 3 with KHSO4 (2M)) and DCM (3×10 ml)
2. washThe combined organic phases were washed with water (2×20 ml)
3. dry with materialdried over Na2SO4
4. filtrationfiltered
5. concentrationconcentrated
6. dissolutionThe oily residue was dissolved in DCM (2 ml)
7. additionTFA (1.3 ml) was added
8. stirringThe mixture was stirred overnight
9. customThe solvent was evaporated
10. customthe removal of TFA
11. dissolutionThe residue was dissolved in methanol (2 ml)
12. waitAfter 15 minutes
13. customthe solvent was removed under reduced pressure
14. customThe residue was purified on preparative HPLC on C8 column

ORD record

ord-15daed6e083b422d97f16fe31bd9e63e

Source dataset

uspto-grants-2011_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07871998B2