申请人:E.R. Squibb & Sons, Inc.
                            
                            
                                公开号:EP0352013A2
                            
                            
                                公开(公告)日:1990-01-24
                            
                            
Antiviral activity is exhibited by compounds having the formula
 and their pharmaceutically acceptable salts.
R₁ is
 
 R₂ is hydrogen, -PO₃H₂, or--R₃ wherein R₃ is hydrogen, alkyl, substituted alkyl, or aryl, and R₄ is alkyl.  
                            具有以下式子的化合物具有抗病毒活性
 及其药学上可接受的盐类。
R₁ 是
 
 R₂ 是氢、-PO₃H₂ 或--R₃ 其中 R₃ 是氢、烷基、取代烷基或芳基,R₄ 是烷基。