Trifluoroacetic acid → N-{[4-((2R,3R)-1-(4-fluorophenyl)-3-{[2-(4-fluorophenyl)-2-oxoethyl]thio}-4-oxoazetidin-2-yl)phenoxy]acetyl}-D-alanine

Participants

Reaction Steps

[4-((2R,3R)-1-(4-fluorophenyl)-3-{[2-(4-fluorophenyl)-2-oxoethyl]thio}-4-oxoazetidin-2-yl)phenoxy]acetic acid (50 mg, 0.1 mmol), tert-butyl D-alaninate (23 mg, 0.12 mmol) and 4-methylmorpholine (31 mg, 0.31 mmol) were dissolved in DCM (1.5 ml) and stirred at room temperature for 5 minutes. TBTU (40 mg, 0.12 mmol) was added and the reaction mixture was stirred for 2 h. TFA (0.7 ml) was added and the solution was stirred for 90 minutes. TFA and DCM were removed under reduced pressure and the residue was dissolved in DCM and washed with water. The organic layer was dried over sodium sulphate and the solvent was removed under reduced pressure giving 55 mg (95%) of the title product. M/z: 553.0 (M−1).

Provenance & Evidence