Abstract: A method for the purification of allopregnanolone is disclosed. Allopregnanolone prepared from isopregnanolone contains impurities such as triphenylphosphine oxide and other unknown impurities. To remove these impurities and purify allopregnanolone, the allopregananolone is dissolved in acetonitrile, and crystallized from the acetonitrile. The resulting crystallized allopregnanolone may then be re-crystallized from acetonitrile to further purify the allopregnanolone.

Abstract: The present invention relates to a method for the preparation of allopregnanolone with a high degree of purity which, eventually, occurs through the formation of 3?-trifluoroacetoxy-5?-pregnan-20-one.

Abstract: A process for the preparation of nucleosides, derivatives and analogues thereof by coupling reaction of a protected suitable nitrogeneous purine or pyrimidine base, a derivative or analogue thereof and a protected suitable sugar in the presence of SnCl4 comprising the removal of SnCl4 by adding DMSO directly into the reaction mixture is described. Preferably said process is used for the preparation of antiviral and antitumor agents having a nucleoside or nucleoside-like structure, still more preferably for the preparation of azacytidine, decitabine, chlorfarabine, cladribine, mizoribine. A residual tin content lower than 300 ppm is obtained with said process.

Abstract: A process for the preparation of nucleosides, derivatives and analogues thereof by coupling reaction of a protected suitable nitrogeneous purine or pyrimidine base, a derivative or analogue thereof and a protected suitable sugar in the presence of SnCl4 comprising the removal of SnCl4 by adding DMSO directly into the reaction mixture is described. Preferably said process is used for the preparation of antiviral and antitumor agents having a nucleoside or nucleoside-like structure, still more preferably for the preparation of azacytidine, decitabine, chlorfarabine, cladribine, mizoribine. A residual tin content lower than 300 ppm is obtained with said process.

Abstract: A process for the preparation of (1S,3?R)-quiniclidin-3?-yl-1-phenyl-3,4-dihydro-1H-isoquinolin-2-carboxylate, namely solifenacin, comprising the reaction of a compound of formula (IV) with a compound of formula (V), as herein defined, and the subsequent reaction with 3-quinuclidinol.

Abstract: A process for the preparation of oxazolidinone derivatives, in particular [(S)—N-[[3-(3-fluoro-4-morpholinyl)phenyl]-2-oxo-5-oxazolidinyl]methyl]-acetamide] (linezolid), and novel intermediates useful for the synthesis thereof.