Patent ID: 6916806

Claim:
A compound of the formula (I): wherein R 1 is optionally substituted heterocyclic group or a group represented by the formula: —C(═Z)W—R 4 wherein Z is oxygen atom or sulfur atom; W is oxygen atom or sulfur atom; R 4 is optionally substituted alkyl, optionally substituted alkenyl or optionally substituted alkynyl; R 2 and R 3 each is independently hydrogen, optionally substituted alkyl, optionally substituted alkoxyalkyl, optionally substituted aminoalkyl, or optionally substituted cycloalkyl; or R 2 and R 3 taken together form optionally substituted C 2 -C 10 straight or branched alkylene which may contain one or three heteroatom(s); m is an integer of 0 to 2; A is optionally substituted aromatic carbocyclic group or optionally substituted aromatic heterocyclic group; provided that when R 1 is a group represented by the formula: —C(═Z)W—R 4 wherein Z is oxygen atom or sulfur atom; W is oxygen atom or sulfur atom; and R 4 is unsubstituted alkyl, R 2 and R 3 taken together form optionally substituted C 2 -C 10 straight or branched alkylene which contains one to three heteroatom(s); a prodrug, a pharmaceutically acceptable salt or a solvate thereof.