Patent ID: 6358992
Filing Date: 2002-03-19
Classification: A61K

Abstract:
A method of treating a mammal having precancerous lesions comprising administering a pharmacologically effective amount of a compound of Formula I or pharmaceutically acceptable salt thereof: whereinR1 is selected from the group consisting of hydrogen, halogen, nitro, carboxy, protected carboxy, acyl, cyano, hydroxyimino(lower)alkyl, lower alkenyl optionally substituted with oxo, or lower alkyl optionally substituted with protected carboxy, carboxy or hydroxy; R2 is selected from the group consisting of hydrogen, halogen, lower alkenyl, acyl, or lower alkyl optionally substituted with protected carboxy, carboxy, lower alkoxy, or hydroxy, alternatively, R1 and R2, together with the carbon atoms to which they are attached form a 4- to 7-membered carbocyclic ring optionally substituted with oxo; R3 is selected from the group consisting of lower alkenyl or lower alkyl, both of which are optionally substituted with one or more substituent(s) selected from the group consisting of (1) oxo, (2) aryl optionally substituted with one or more substituents selected from the group consisting of halogen, aryl, lower alkoxy, lower aklylenedioxy, cyano, nitro, carboxy, protected carboxy, acyl, and amino optionally substituted with acyl or protected carboxy, and (3) a heterocyclic group optionally substituted with halogen; and R4 is selected from the group consisting of carboxy, protected carboxy, acyl, cyano, halogen, a heterocyclic group, amino optionally substituted with acyl or protected carboxy, or lower alkyl optionally substituted with protected carboxy, carboxy, or acyl; or its pharmaceutically acceptable salt.