Amide derivative

1. An amide derivative represented by the following general formula (I) or a salt thereof

(symbols in the formula have the following meanings; R 1 and R 2 : the same or different from each other, and each represents —H, -lower alkyl, -lower alkenyl, -lower alkynyl, -cycloalkyl, -cycloalkenyl, —NRaRb, —NRc-NRaRb, —NRc-(nitrogen-containing saturated heterocyclic ring which may be substituted with lower alkyl), —NRc-C(═NH)—NRaRb, -(nitrogen-containing saturated heterocyclic ring which may be substituted with lower alkyl , -lower alkylene-NRaRb, -lower alkylene-(nitrogen-containing saturated heterocyclic ring which may be substituted with lower alkyl), —NRaCORb, —NRaCO—ORb, —NRaCO—NRbRc, —NRaCO-lower alkylene-NRbRc, —NRaCO-lower alkylene-(nitrogen-containing saturated heterocyclic ring which may be substituted with lower alkyl), —NRaSO 2 Rb, —NRaSO 2 —NRbRc, —NRaSO 2 -lower alkylene-NRbRc, —NRaSO 2 -lower alkylene-(nitrogen-containing saturated heterocyclic ring which may be substituted with lower alkyl), —CONRaRb, —SO 2 NRaRb, —COORa, —SO 2 Ra, —CONRa—ORb, —OCORa, —ORa, -halogen, —CORa, —NO 2 , —CN or -halogeno lower alkyl,

Ra, Rb and Rc: the same or different from one another, and each represents —H, -lower alkyl, -lower alkenyl, -lower alkynyl, -cycloalkyl, -cycloalkenyl, -aryl, -5- or 6- membered monocyclic heteroaryl or -lower alkylene-aryl,

A: -aryl which may have one or more substituents, -heteroaryl which may have one or more substituents, -saturated carbon ring-condensed aryl which may have one or ore substituents or -saturated heterocyclic ring-condensed aryl which may have one or more substituents, wherein the saturated carbon ring-condensed aryl and saturated heterocyclic ring-condensed aryl bind to the adjacent N atom via C atom of the aromatic ring,

X: CO or SO 2 ,

R 3 : -alkyl which may have one or more substituents, -alkenyl which may have one or more substituents, -alkynyl which may have one or more substituents, -cycloalkyl which may have one or more substituents, -cycloalkenyl which may have one or more substituents, -aryl which may have one or more substituents, -hetero ring which may have one or more substituents or —NRaRb, or it may form a group represented by the following formula together with the adjacent group —N(-A)—X—,

Y: O,S, a bond or CH 2 , R 3a : —H, -cycloalkyl which may have one or more substituents, -cycloalkenyl which may have one or more substituents, -aryl which may have one or more substituents or -hetero ring which may have one or more substituents, and

A′ and B: the same or different from each other, and each represents benzene ring which may have one or more substituents).

2. The amide derivative or a salt thereof according to claim 1 , wherein R 1 and R 2 may be the same or different from each other and each represents —H, -lower alkyl, -lower alkenyl, -lower alkynyl, —NRaRb, —NRc-NRaRb, -(nitrogen-containing saturated heterocyclic ring which may be substituted with lower alkyl), —NRc-C(═NH) NRaRb, NRaCORb, —NRaCO—ORb, —NRaCO—NRbRc, —NRaCO-lower alkylene-NRbRc or —NRaCO-lower alkylene-(nitrogen-containing saturated heterocyclic ring which may be substituted with lower alkyl),

A is, aryl which may have 1 to 5 substituents selected from a group D, heteroaryl which may have 1 to 5 substituents selected from the group D, saturated carbon ring-condensed aryl which may have 1 to 5 substituents selected from the group D or saturated heterocyclic ring-condensed aryl which may have 1 to 5 substituents selected from the group D, and

R 3 is cycloalkyl which may have 1 to 5 substituents selected from the group D, cycloalkenyl which may have 1 to 5 substituents selected from the group D, aryl which may have 1 to 5 substituents selected from the group D, saturated carbon ring-condensed aryl which may have 1 to 5 substituents selected from the group D, saturated heterocyclic ring-condensed aryl which may have 1 to 5 substituents selected from the group D, heteroaryl which may have 1 to 5 substituents selected from the group D or 5- to 8-membered monocyclic saturated heterocyclic ring which may have 1 to 5 substituents selected from the group D,

wherein the group D represents -(lower alkyl which y have 1 or 2 substituents selected from —ORa, —SRa, —CN, —COORa, —CONRaRb, —NRaRb and -(nitrogen-containing saturated heterocyclic ring which may have one or more substituents selected from -lower alkyl, -lower alkylene-COORa and —NRaRb), -lower alkenyl, -lower alkynyl, -halogeno lower alkyl, 5- or 6-membered monocyclic heteroaryl, -cycloalkyl, -cycloalkenyl, -aryl, —NRaRb —NRc—NRaRb, -(nitrogen-containing saturated heterocyclic ring which may have one or more substituents selected from -lower alkyl, -lower alkylene-COORa and —NRaRb), —NRc-(nitrogen-containing saturated heterocyclic ring which may have one or more substituents selected from -lower alkyl, -lower alkylene-COORa and NRaRb), O-lower alkylene- NRaRb, —O-lower alkylene-(nitrogen-containing saturated heterocyclic ring which may have one or more substituents selected from -lower alkyl, -lower alkylene-COORa and —NRaRb), —O-lower alkylene-ORa, —O-lower alkyl-COORa, —COORa, -halogen, —CORa, —NO 2 , —CN, —ORa, —O-(halogeno lower alkyl), —SRa, —SORa, —SO 2 Ra, —CO—NRaRb, —CO-(nitrogen-containing saturated heterocyclic ring which may have one or more substituents selected from -lower alkyl, -lower alkylene-COORa and —NRaRb), —NRa—CORb, —SO 2 NRaRb or ═O(oxo).

3. The amide derivative or a salt thereof according to claim 1 , wherein X is CO.

4. The amide derivative or a salt thereof according to claim 1 , wherein R 1 is —NH 2 and R 2 is —H.

5. The amide derivative or a salt thereof according to claim 1 , wherein it is selected from

N-({[4-(2-Aminothiazol-4-yl)phenyl]carbamoyl}methyl)-4-fluoro-N-(2,3-dihydro- 1H-indol-6-yl)benzamide; N-({[4-(2-aminothiazol-4-yl-)phenyl]carbamoyl}methyl)-4-fluoro-N-(1,2,3,4-tetradihydroquinolin-6-yl)benzamide; N-({[4-(2-aminothiazol-4-yl)phenyl]carbamoyl}methyl)-N-(2,3-dihydro-1,4-benzodioxin-6-yl)-4-fluorobenzamide; N-({[4-(2-aminothiazol-4-yl)phenyl]carbamoyl}methyl)-N-(1,3-benzodioxol-5yl)-4-fluorobenzamide; N-({[4-(2-aminothiazol-4-yl)phenyl]carbamoyl}methyl)-N-benzothiazol-5-yl-4-fluorobenzamide; N-({[4-(2-aminothiazol-4-yl)phenyl]carbamoyl}methyl)-N-benzothiazol-6-yl-4-fluorobenzamide; N-({[4-(2-aminothiazol-4-yl)phenyl]carbamoyl}methyl)-4-fluoro-N-indan-5-ylbenzamide; N-({[4-(2-aminothiazol-4-yl)phenyl]carbamoyl}methyl)-4-fluoro-N-(3-hydroxyindan-5-yl)benzamide; N-({[4-(2-aminothiazol-4-yl)phenyl]carbamoyl}methyl)-4-fluoro-N-(1H-indol-5-yl)benzamide; N-({[4-(2-aminothiazol-4-yl)phenyl]carbamoyl}methyl)-4-fluoro-N-(3-oxo-3,4-dihydro-2H-1,4-benzothiazin-6-yl)benzamide; N-({[4-(2-aminothiazol-4-yl)phenyl]carbamoyl}methyl)-4-fluoro-N-(3-oxo-3,4-dihydro-2H- 1,4-benzoxazin-6-yl )benzamide; N-({[4-(2-aminothiazol-4-yl)phenyl]carbamoyl}methyl)-N-(1,2,3-benzothiadiazol-5-yl)-4-fluorobenzamide; N-({[4-(2-aminothiazol-4-yl)phenyl]carbamoyl}methyl)-N-(4-methoxyphenyl)tetrahydro-2H-thiopyran-4-carboxamide 1,1-dioxide; N-({[4-(2-aminothiazol-4-yl)phenyl]carbamoyl}methyl)-N-benzothiazol-5-yl-4-fluorocyclohex-3-enecarboxamide; N-({[4-(2-aminothiazol-4-yl)phenyl]carbamoyl}methyl)-N-benzothiazol-5-yl-4,4-difluorocyclohexanecarboxamide; and N-({[4-(2-aminothiazol-4-yl)phenyl]carbamoyl}methyl)-N-indan-5-yltetrahydro-2H-thiopyran-4-carboxamide 1,1-dioxide.

6. A pharmaceutical composition which comprises the amide derivative or a salt thereof described in claim 1 and a pharmacologically acceptable carrier.

7. The pharmaceutical composition according to claim 6 , wherein it is an anti-herpesvirus agent.

8. The pharmaceutical composition according to claim 7 , wherein it is an anti-varicella zoster virus agent.