3-substituted cinnolinones having the following structural formula are disclosed: ##SPC1## Wherein R.sub.1 is hydrogen, lower alkyl, aralkyl or acyl and R.sub.2 and R.sub.3 are hydrogen, halogen, lower alkoxy or lower alkyl, and X is ##EQU1## CH.sub.3 COOCH.sub.2 S-, or ##SPC2## These compounds are useful as immunosuppressants.
                            本发明揭示了具有以下结构式的3-取代基
香豆素酮:##
SPC1## 其中R1为氢、低碳基、芳基烷基或酰基,R2和R3为氢、卤素、低烷氧基或低碳基,X为##EQU1## CH.sub.3 COOCH.sub.2 S-,或##
SPC2## 这些化合物可用作
免疫抑制剂。