Compounds of formula (I): 
and pharmaceutically acceptable salts thereof, wherein one of R1 and R2 is H and the other is N═C(NH2)2 or NHC(═NH)NH2, and the other substituents are as defined herein, are urokinase (uPA) inhibitors.
                            式(I)的化合物及其药用盐,其中R1和R2中的一个是H,另一个是NHC(NH2)2或NHC(NH)NH2,其他取代基如本文所定义,是
尿激酶(uPA)
抑制剂。