4-Methylmorpholine → N2-{[4-((2R,3R)-1-(4-fluorophenyl)-3-{[2 (4-fluorophenyl)-2-hydroxyethyl]thio}-4-oxoazetidin-2-yl)phenoxy]acetyl}-L-glutaminyl-D-phenylalanine

Participants

Reaction Steps

N2-{[4-((2R,3R)-1-(4-fluorophenyl)-3-{[2-(4-fluorophenyl)-2-hydroxyethyl]thio}-4-oxoazetidin-2-yl)phenoxy]acetyl}-L-glutamine (15 mg, 0.0244 mmol), tert-butyl D-phenylalaninate hydrochloride (8 mg, 0.0310 mmol) and N-methylmorpholine (10 mg, 0.099 mmol) were dissolved in methylene chloride (0.5 ml). TBTU (10 mg, 0.0313 mmol) was added and the mixture was stirred for 1 h at room temperature. The solvent was evaporated and the residue was dissolved in formic acid (0.5 ml). The mixture was heated to 45-50° C. and stirred at this temperature for 6 h. The reaction mixture was evaporated under reduced pressure. Methanol (5 ml) was added and evaporated. The residue was dissolved in methanol (1 ml). Two drops of TEA was added and the mixture was stirred overnight at room temperature. The solvent was evaporated and the residue was purified by preparative HPLC using acetonitrile/ammonium acetate buffer (40:60) as eluent. After freeze-drying 12 mg (64%) of the title compound was obtained. 1H-NMR, 300 MHz, DMSO): 1.55-1.97 (m, 4H), 2.77-3.10 (m, 4H), 4.20-4.38 (m, 3H), 4.49 (s, 2H), 4.66-4.78 (m, 1H), 4.99-5.07 (m, 1H), 6.70 (s, 1H), 6.88-7.40 (m, 19H), 8.00-8.20 (m, 2H).

Provenance & Evidence