Pyridone derivatives having a binding activity to the cannabinoid type 2 receptor

A library of compound of the formula (I):

• wherein R1 is a group represented by the formula:
• —Y1—Y2—Y3—Ra wherein Y1 is single bond;
• Y3 is single bond or optionally substituted alkylene;
• Y2 is —C(═O)—NRb—;
• Ra is optionally substituted carbocyclic group or optionally substituted heterocyclic group;
• Rb is hydrogen;
• R2 is hydrogen;
• R3 and R4 taken together with adjacent atom form unsubstituted carbocyclic group (provided that the bond between carbon atom substituted with R3 and carbon atom substituted R4 is the double bond, and the other bonds between carbon atoms are single bond)
• R5 is C3 or more alkyl or a group represented by the formula:
• —Y6—Re wherein Y6 is optionally substituted alkylene;
• Re is optionally substituted aryl optionally substituted cycloalkyl or optionally substituted heteroaryl;
• X is S or O.

A library of compound of the formula (I):

• wherein R1 is a group represented by the formula:
• —Y1—Y2—Y31Ra wherein Y1 is single bond;
• Y2 is —C(═O)—NRb—;
• Y3 is single bond or optionally substituted alkylene;
• Ra is optionally substituted carbocyclic group or optionally substituted heterocyclic group;
• Rb is hydrogen;
• R2 is hydrogen;
• R3 is a group represented by the formula:
• —Y5—Rd wherein Y5 is single bond;
• Rd is optionally substituted aryl optionally substituted cycloalkyl or optionally substituted heteroaryl;
• R4 is hydrogen or alkyl;
• R5 is C3 or more alkyl or a group represented by the formula:
• —Y6—Re wherein Y6 is optionally substituted alkylene;
• Re is optionally substituted aryl optionally substituted cycloalkyl or optionally substituted heteroaryl;
• X is S or O.

A library of compound of the formula (I):

• wherein R1 is a group represented by the formula:
• —Y1—Y2—Y3—Ra wherein Y1 and Y3 are single bond;
• Y2 is —NRb—C(═O)—;
• Ra is optionally substituted carbocyclic group;
• Rb is hydrogen;
• R2 is hydrogen;
• R3 and R4 each is independently alkyl;
• R5 is C3 or more alkyl;
• X is O.

A compound of the formula:

• wherein Y is single bond, —NH—, —O—, or —(CH2)1-5—;
• Y2 is —C(═O)—NH— or —NH—C(═O)—;
• Y3 is single bond or optionally substituted alkylene;
• Ra is optionally substituted aryl, optionally substituted cycloalkyl, optionally substituted cycloalkenyl, optionally substituted heteroaryl or optionally substituted heterocyclic group;
• R5 is C3 or more alkyl or a group represented by the formula:
• —Y6—Re— wherein Y6 is alkylene;
• Re is optionally substituted aryl, optionally substituted cycloalkyl, optionally substituted heteroaryl, or optionally substituted heterocyclic group;
• a prodrug, a pharmaceutically acceptable salt or solvate thereof.

A compound of the formula:

• wherein R3 and R4 each is independently alkyl;
• Y2 is —C(═O)—NH— or —NH—C(═O)—;
• Y3 is single bond or optionally substituted alkylene;
• Ra is optionally substituted aryl, optionally substituted cycloalkyl, optionally substituted cycloalkenyl, optionally substituted heteroaryl or optionally substituted heterocyclic group;
• R5 is C3 or more alkyl or a group represented by the formula:
• —Y6—Re— wherein Y6
• is alkylene;
• Re is optionally substituted aryl, optionally substituted cycloalkyl, optionally substituted heteroaryl, or optionally substituted heterocyclic group;
• a prodrug, a pharmaceutically acceptable salt or solvate thereof.