| abstract |
The invention relates to a method for industriallynproducing highly pure (2R, 3S)- or (2S, 3R)-N-carbamate-protectednβ-aminoepoxide (crystal) or (2R, 3S)- or (2S,n3R)-N-carbamate-protected β-aminoalcohol. The method fornproducing N-carbamate-protected β-aminoepoxide crystal,ncomprises the following steps (a) to (d):n (a) a step of dissolving (2R, 3S)- or (2S, 3R)-N-carbamate-protectednβ-aminoalcohol containing at least thendiastereomer as an impurity in a solvent comprising at leastnone or more selected from aromatic hydrocarbon solvent,nsaturated hydrocarbon solvent, aqueous mixture solvent,nacetone and 2-propanol, to remove insoluble matters; (b) a step of treating the (2R, 3S)- or (2S, 3R)-N-carbamate-protectednβ-aminoalcohol with a base, therebynconverting the N-carbamate-protected β-aminoalcohol to (2R,n3S)- or (2S, 3R)-N-carbamate-protected β-aminoepoxide; (c) a step of treating the (2R, 3S)- or (2S, 3R)-N-carbamate-protectednβ-aminoepoxide containing at least thendiastereomer as an impurity with an acid, thereby convertingnthe diastereomer as an impurity to (4S, 5R) or (4R, 5S)noxazolidin-2-one derivative, nand optionally separating and removing the resulting oxazolidin-2-onenderivative in water or an aqueous mixture solvent; and n(d) a step of crystallizing the (2R, 3S)- or (2S, 3R)-N-carbamate-protected nβ-aminoepoxide in a mixture solvent ofnwater and water-miscible organic solvent. |