| 摘要 |
Process for the preparation of a threo-phenylserine amide of general formula (2) in which glycine amide is contacted with the corresponding substituted benzaldehyde of formula (3) in an excess relative to the amount of glycine amide, this taking place at a pH between 9 and 14 in the presence of a suitable solvent. The resulting phenylserine amide can subsequently be hydrolyzed to a phenylserine amide of general formula (1), which is subsequently hydrolyzed to a phenylserine amide of general formula (1), which is subsequently subjected to a stereoselective enzymatic hydrolysis yielding a (2S,3R)-phenylserine. The non-hydrolyzed (2R,3S)-phenylserine amide can be isolated as a Schiff base and be recirculated and simply racemized. The (2S,3R)-phenylserine obtained can be used in the preparation of thiamphenicol or phlorophenicol. The threo-phenylserine amides of general formula (1) or (2) are new intermediates in this commercially attractive process for the preparation of thiamphenicol and phlorophenicol.
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