申请人:UPJOHN CO
                            
                            
                                公开号:WO2003053972A1
                            
                            
                                公开(公告)日:2003-07-03
                            
                            The present invention provides a compound of formula (I) or a pharmaceutically acceptable salt thereof wherein R?1 and R2¿ are as defined in the specification. The compounds are useful for the treatment of viral infections.