4-Methylmorpholine → N-({4-[(2R,3R)-3-{[2-(1,3-Benzodioxol-5-yl)-2-hydroxyethyl]thio}-1-(4-fluorophenyl)-4-oxoazetidin-2-yl]phenoxy}acetyl)glycyl-3-cyclohexyl-D-alanine

Participants

Reaction Steps

To a solution of {4-[(2R,3R)-3-{[2-(1,3-benzodioxol-5-yl)-2-oxoethyl]thio}-1-(4-fluorophenyl)-4-oxoazetidin-2-yl]phenoxy}acetic acid (Method 7) (0.025 g, 0.049 mmol) and NMM (0.020 ml, 0.178 mmol) in DMF (3 ml) at RT was added TBTU (0.020 g, 0.062 mmol). The reaction mixture was stirred for 90 min after which glycyl-3-cyclohexyl-D-alanine (Method 9) (0.012 g, 0.035 mmol) was added. The mixture was stirred for 20 h before the reaction was quenched by the addition of water (1 ml). The mixture was diluted with methanol (2 ml) and then NaBH4 (0.028 g, 0.740 mmol) was added. After 15 min the reaction was quenched by the addition of an aqueous solution of hydrochloric acid (1M, 1 ml) and most of the methanol was removed under reduced pressure. The remaining solution was purified by preparative HPLC using a gradient of 20-60% MeCN in a 0.1M ammonium acetate buffer as eluent. Freeze-drying of the pure fractions gave the desired product as.

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