| 摘要 |
A process for the preparation of a purine derivative corresponding to the following general formula: <CHEM> characterised in that it comprises: protecting the hydroxyl groups of the sugar moiety of a starting material corresponding to the following general formula: <CHEM> activating the 6-position of the purine ring; introducing the substituent B at this position; and removing the sugar moiety; wherein A represents NH2 or H; B represents a substituent which has the effect of favouring subsequent substitution at the 9-position of the purine ring and which will withstand removal of the sugar moiety, but which may later be removed or converted; and Z represents: <CHEM> is disclosed. The present purine derivatives obtainable by the above process may be used in a disclosed process for the preparation of a nucleoside analogue characterised in that it comprises; introducing a side chain at the 9-position of the purine derivative; and removing or converting the substituent B at the 6-position of the purine derivative. |
