Patent ID: 7112598

Claim:
A compound or a salt thereof represented by the following formula [III], wherein R 1 is acyl; R 2 is hydrogen, halogen, unsubstituted alkyl or alkyl substituted by halogen; R 3 is halogen or alkoxy; R 4 is cycloalkyl, unsubstituted alkyl or alkyl substituted by cycloalkyl, aryl or hydroxyl or an ester thereof or alkoxy; R 5 is hydroxyl or an ester thereof, alkoxy or -A 2 -R 6 ; or R 4 and R 5 are bonded with each other to form a pyrrolidine ring substituted by hydroxyl or an ester thereof, alkoxy or alkoxyalkyl; R 6 is hydroxyl or an ester thereof, alkoxy, alkoxyalkoxy, alkoxyalkoxyalkoxy, mercapto or alkylthio; and A 1 and A 2 , are the same or different, and are alkylene, provided that (i) when R 4 and R 5 are bonded to each other to form the pyrrolidine ring substituted by hydroxyl or an ester thereof, R 2 is halogen; (ii) when R 4 and R 5 are bonded to each other to form the pyrrolidine ring substituted by alkoxyalkyl, R 2 is hydrogen; (iii) when R 6 is hydroxyl or an ester thereof, R 4 is isopropyl.