Synthesis of nucleosides

摘要

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.

主权项

1. A process for preparation of a nucleoside, a derivative of a nucleoside, or an analogue of a nucleoside, comprising:
coupling a suitably protected nitrogenous purine or pyrimidine base, a derivative or analogue thereof with a suitably protected sugar in a reaction mixture containing SnCl4, and removing SnCl4 is removed from the reaction mixture by adding DMSO directly into the reaction mixture and subsequently filtering a resultant SnCl4-DMSO complex.