Compound of the formula (I'):
 wherein
   G' is an acyl group, optionally protected hydroxyalkyl group having not less than 2 carbon atoms, or halogen atom;
   X is an oxygen atom, optionally oxidized sulfur atom or -(CH₂)q- in which q is an integer of 0 to 5;
   R is an optionally substituted amino group or optionally substituted heterocyclic group;
   each of the ring A and ring B may optionally be substituted; and
   k is 0 or 1;
or a salt thereof.
The compounds of formula (I') are useful as anti-inflammatory agents, particularly for treating arthritis.
                            式 (I') 的化合物:
 其中
G' 是酰基、具有不少于 2 个碳原子的受保护羟烷基或卤素原子;
X 是氧原子、任选氧化的
硫原子或-(CH₂)q-,其中 q 是 0 至 5 的整数;
R 是任选取代的
氨基或任选取代的杂环基团;
环 A 和环 B 可任选被取代;以及
k 为 0 或 1;
或其盐。
式(I')化合物可用作抗炎剂,特别是用于治疗关节炎。