1-Ethyl-3-(3'-dimethylaminopropyl)carbodiimide → (1S,5S)-(1-{5-[(4-amino-benzenesulfonyl)-isobutyl-amino]-6-phosphonooxy hexylcarbamoyl}-2,2-diphenyl-ethyl)-carbamic acid methyl ester

Participants

Reaction Steps

(2S)-2-methoxycarbonylamino-3,3-diphenyl-propionic acid ((example 1, step E) 0.9 g, 3 mmol) was activated in DMF (5 mL) with EDAC (1.7 g, 9 mmol) and HOBt (1.2 g, 9 mmol). To the solution was added 1.17 g of (2S)-phosphoric acid 6-amino-2-[(4-amino -benzenesulfonyl)-isobutyl-amino]-hexyl ester diethyl ester (1X) (example 3, step B) and the mixture stirred for 3 h. 20 g of Amberlite XAD-2 resin was then added and the beads were left to soak for 10 min. The resin was transferred into a glass filter and washed thoroughly with distilled water (400 mL) and 200 mL of 1M NaHCO3. The beads were then washed with 4×50 ml portions of MeOH then EtOAc 200 mL. The organic phase was evaporated. The residue was adsorbed onto silica gel and passed through a short silica gel column (EtOAc) to yield 2.4 g (83%) of white solid after evaporation.

Provenance & Evidence