Patent ID: 8088924

Claim:
A library of compounds of the formula (I): wherein R 1 is a group represented by the formula: —Y 1 —Y 2 —Y 3 —R a wherein Y 1 is single bond; Y 2 is —C(═O)—NR b —; Y 3 is single bond or optionally substituted alkylene; R a is optionally substituted carbocyclic group or optionally substituted heterocyclic group; R b is hydrogen; R 2 is hydrogen; R 3 is a group represented by the formula: —Y 5 —R d wherein Y 5 is single bond; R d is optionally substituted aryl optionally substituted cycloalkyl or optionally substituted heteroaryl; R 4 is hydrogen or alkyl; R 5 is C 3 or more alkyl or a group represented by the formula: —Y 6 —R e wherein Y 6 is optionally substituted alkylene; R e is optionally substituted aryl optionally substituted cycloalkyl or optionally substituted heteroaryl; X is S or O; or a pharmaceutically acceptable salt thereof.