Phenyl chloroformate → (S)-2-ethoxy-3-(4-{2-[4-(phenoxycarbonylamino)phenyl]ethoxy]phenyl)propanoic acid ethyl ester

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Reaction Steps

3-{4-[2-(4-Aminophenyl)ethoxy]phenyl}-(S)-2-ethoxypropanoic acid ethyl ester hydro chloride (described in Example 41b) (0.55 g; 1.4 mmole) was dissolved in tetrahydrofuran (5 ml). Phenyl chloroformat (0.675 g; 3 mmole) was added slowly. The reaction mixture was stirred at room temperature and continuosly checked with HPLC and after 3 days was all the starting material consumed. Water was added, tetrahydrofuran evaporated and the residue extracted three times with ethyl acetate. The organic phase was dried with magnesium sulfate and evaporated. Purification of the crude product with preparative HPLC (Kromasil C8, 7 μm, 50×250 mm) using acetronitrile (70%) in ammonium acetate buffer (pH 7) as mobil phase gave 0.46 g (96.3% yield) (S)-2-ethoxy-3-(4-{2-[4-(phenoxycarbonylamino)phenyl]ethoxy]phenyl)propanoic acid ethyl ester.

Provenance & Evidence