4-ALKANOYLAMINO-3-PYRAZOLONE DERIVATIVE

The present invention provides a compound which enhances the production of erythropoietin. The present invention provides, for example, a compound represented by the formula (1) wherein R 1 : -Q 1 , -Q 1 -X-Q 2 , or -Q 1 -X-Q 2 -Y-Q 3 ; Q 1 : a monocyclic or bicyclic aromatic heterocyclic group; Q 2 , Q 3 : an aromatic hydrocarbon ring group or a monocyclic aromatic heterocyclic group; X: -CONH-, -CONHCH 2 -, -CH 2 OCH 2 -, -NHCH 2 CH 2 -, or the like; Y: a single bond, -O-, - (CH 2 ) n -, or -O-(-CH 2 ) n -; m, n: an integer from 1 to 3; R 2 : H or an alkyl group; and R 3 : H, an alkoxycarbonyl group, a carboxy group, an aromatic hydrocarbon ring group, or a monocyclic aromatic heterocyclic group.