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

Participants

Reaction Steps

TBTU (0.016 g, 0.051 mmol) was added to a solution of N-{[4-((2R,3R)-1-(4-fluorophenyl)-3-{[2-(4-fluorophenyl)-2-oxoethyl]thio}-4-oxoazetidin-2-yl)phenoxy]acetyl}glycine (0.025 g, 0.046 mmol) and N-methylmorpholine (0.014 g, 0.139 mmol) in DMF (2 ml) at 30° C. After 1 h, DMSO (1 ml) and D-tryptophan (0.019 g, 0.092 mmol) were added. After 10 minutes, the reaction was quenched by the addition of water (1 ml). The mixture was stirred for 10 minutes and MeOH (1 ml) and NaBH4 (0.035 g, 0.925 mmol) were added. After 5 minutes, full conversion to the corresponding alcohol was obtained. The reaction was quenched by the addition of 0.1M NH4OAc buffer (1 ml). The reaction mixture was concentrated and the residue was purified by preparative HPLC using an eluent of 0-50% CH3CN in 0.1M NH4OAc buffer. This gave the title compound (0.028 g, 83%) as a colurless solid. M/z: 727.0 (M−1). 1H NMR [(CD3)2SO), 400 MHz] δ 2.79-3.18 (m, 4H), 3.61-3.80 (m, 2H), 4.26-4.34 (m, 2H), 4.43-4.54 (m, 2H), 4.68-4.78 (m, 1H), 4.97-5.04 (m, 1H), 6.84-7.55 (m, 1H), 7.65-7.82 (m, 1H), 8.22-8.25 (m, 1H), 10.73 (s, 1H).

Provenance & Evidence