| 摘要 |
A compound of formula (II): <CHEM> or a pharmaceutically acceptable salt or in vivo hydrolysable ester thereof, wherein one of R<1> or R<2> is hydrogen, and the other is a group of subformula (a): <CHEM> wherein R<4> is a substituent group, X is an oxygen atom, a sulphur atom or an -NR<5> group wherein R<6> is hydrogen hydrocarbon or a nitrogen protecting group, and n is 0, 1, 2 or 3; and R<3> represents hydrogen or an organic group. Processes for preparing these compounds and pharmaceutical compositions containing them are also described. |
