| abstract |
The present invention provides novel cathecol hydrazone derivatives of formula (I) or pharmaceutically acceptable salts thereof, wherein R1 is C1-7 alkyl or C3-7 cycloalkyl; R2 is hydrogen, hydroxy, C1-5 alkyl or -CH2CH2C(=O)NH2; R3 and R4 are independently hydrogen, C1-7 alkyl, -C(=X)-R5, or 2-, 3- or 4-pyridyl, prymidyl or phenyl substituted with one or two selected from a group consisting of halogen, C1-6 alkoxy, nitro, trifluoromethyl, C1-6 alkyl and carboxyl, or R3 and R4 are directly bonded by C3-4 containing oxygen, sulfur or nitrogen to form a heterocyclic ring, X is oxygen, sulfur or NH and R5 is C1-7 alkyl, -NHR6, CONH2 or 2-, 3- or 4-pyridyl, prymidyl or phenyl substituted with one selected from a group consisting of halogen, C1-6 alkoxy, nitrile, trifluoromethyl, C1-6 alkyl and carboxyl, and R6 is hydrogen, hydroxy, NH2, C1-5 alkoxy, C1-5 alkyl, pyridyl or phenyl. |