Oblon, Spivak, McClelland, Maier & Neustadt, P.C.
Method for producing epoxide crystal
The invention relates to a method for industrially producing highly pure (2R, 3S)- or (2S, 3R)-N-carbamate-protected &bgr;-aminoepoxide (crystal) or (2R, 3S)- or (2S, 3R)-N-carbamate-protected &bgr;-aminoalcohol. The method for producing N-carbamate-protected &bgr;-aminoepoxide crystal, includes one or more of the following steps (a) to (d):(a) dissolving (2R, 3S)- or (2S, 3R)-N-carbamate-protected &bgr;-aminoalcohol containing at least the diastereomer as an impurity in a solvent including at least one or more selected from aromatic hydrocarbon solvent, saturated hydrocarbon solvent, aqueous mixture solvent, acetone and 2-propanol, to remove insoluble matters;(b) treating the (2R, 3S)- or (2S, 3R)-N-carbamate-protected &bgr;-aminoalcohol with a base, thereby converting the N-carbamate-protected &bgr;-aminoalcohol to (2R, 3S)- or (2S, 3R)-N-carbamate-protected &bgr;-aminoepoxide;(c) treating the (2R, 3S)- or (2S, 3R)-N-carbamate-protected &bgr;-aminoepoxide containing at least the diastereomer as an impurity with an acid, thereby converting the diastereomer as an impurity to (4S, 5R) or (4R, 5S) oxazolidin-2-one derivative, and optionally separating and removing the resulting oxazolidin-2-one derivative in water or an aqueous mixture solvent; and(d) crystallizing the (2R, 3S)- or (2S, 3R)-N-carbamate-protected &bgr;-aminoepoxide in a mixture solvent of water and water-miscible organic solvent. By the methods of the present invention, highly pure (2R, 3S)- or (2S, 3R)-N-carbamate-protected &bgr;-aminoepoxide or (2R, 3S) or (2S, 3R)-N-carbamate-protected &bgr;-aminoalcohol can be efficiently produced.
Ajinomoto Co., Inc.
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C07D C07C C07D C07B C07C
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Takashi Yasuyuki Tomoyuki Naoko Masakazu Yutaka Kunisuke
Nakano Otake Onishi Hirose Nakazawa Honda Izawa