摘要 |
Compounds useful as antiviral agents are defined by the following formula: <IMAGE> (I) and the pharmaceutically acceptable acid addition salts thereof wherein R1 is hydrogen or -C(O)R7 wherein R7 is hydrogen, alkyl of one to nineteen carbon atoms, hydroxyalkyl of one to eight carbon atoms, alkoxyalkyl of two to nine carbon atoms, alkenyl of two to nineteen carbon atoms, phenyl, 1-adamantyl or 2-carboxyethyl and the pharmaceutically acceptable alkali metal salts thereof; R2 is -C(O)R7 wherein R7 is as defined above; R3 is hydrogen, halo, thio, lower alkylthio of one to six carbon atoms, azido, NR9R10 wherein R9 and R10 are independently hydrogen or lower alkyl of one to six carbon atoms or -NHC(O)R8 wherein R8 is hydrogen, alkyl of one to nineteen carbon atoms or 1-adamantyl; and (a) R6 is hydrogen, halo, lower alkoxy of one to six carbon atoms, azido, thio, lower alkylthio of one to six carbon atoms, -NR9R10 wherein R9 and R10 are as defined above or -NHC(O)R8 wherein R8 is as defined above and R4 together with R5 is a bond; or (b) R5 together with R6 is a keto group and R4 is hydrogen. |