| 摘要 |
A compound of formula (I) or a pharmaceutically acceptable salt thereof: <IMAGE> (I) wherein: R1 is hydrogen, C1-6 alkyl, C1-6 alkoxy or halogen; R2 and R3 are both hydrogen or together represent a bond; R4 is selected from C1-6 alkyl, phenyl, phenyl C1-4 alkyl, COR8 where R8 is hydroxy, C1-6 alkoxy or NR9R10 where R9 and R10 are independently hydrogen or C1-4 alkyl and CH2OR11 and R11 is hydrogen, C1-4 alkyl or C1-4 alkanoyl; R5 is hydrogen, C1-6 alkyl or phenyl C1-4 alkyl; R6 is phenyl C1-7 alkyl in which the phenyl moiety is optionally substituted by one or two of halogen, ortho-nitro, meta- or para-methoxy, methyl or NR12R13 wherein R12 and R13 are independently hydrogen or C1-6 alkyl or R12 and R13 together are C2-6 polymethylene or the phenyl moiety is 3,4-disubstituted by methylenedioxy or ethylenedioxy; and R7 is hydrogen or C1-4 alkyl, processes for its preparation and its use as a pharmaceutical. |
