Tetracyclic fused heterocyclic compound and use thereof as HCV polymerase inhibitor

Abstract

The present invention relates to a tetracyclic fused heterocyclic compound represented by the following formula [I] wherein each symbol is as defined in the specification, or a pharmaceutically acceptable a salt thereof, and a hepatitis C virus (HCV) polymerase inhibitor and a therapeutic agent for hepatitis C containing this compound. The compound of the present invention shows an anti-HCV activity based on the HCV polymerase inhibitory activity, and useful as an agent for the prophylaxis or treatment of hepatitis C.

1 . A compound represented by the following formula [I] or a pharmaceutically acceptable salt thereof:  
     
       
         
         
             
             
         
       
       is C═C—N or N—C═C,  
       G 3 , G 4  and G 5  are each independently a carbon atom or a nitrogen atom, when at least one of G 3 , G 4  and G 5  is a carbon atom, said carbon atom is optionally substituted by R 3 ,  
       Q is  
       (1) —(CH 2 ) b — or  
       (2) —(CH 2 ) c -Q 1 -(CH 2 ) d — 
       (wherein b is an integer of 1 to 4,  
       c and d are each independently 0 or an integer of 1 to 4,  
       Q 1  is  
       (1′) —O—,  
       (2′) —NH—,  
       (3′) —S—,  
       (4′) —OCO—,  
       (5′) —OCONH—,  
       (6′) —CO—,  
       (7′) —SO—,  
       (8′) —SO 2 —,  
       (9′) —NHCO—,  
       (10′) —NHSO 2 —,  
       (11′) —NHCOO—,  
       (12′) —COO—,  
       (13′) —CONH—,  
       (14′) —SO 2 NH—,  
       (15′) —NHCONH—,  
       (16′) —NHSO 2 NH—,  
       (17′) —CH═CH—,  
       (18′) —CH═N— or  
       (19′) —N═CH—),  
       ring A is  
       (1) benzene,  
       (2) cyclopentane or cyclohexane,  
       (3) cyclopentene or cyclohexene or  
       (4) a 5- or 6-membered heterocycle comprising 1 to 4 heteroatoms selected from oxygen atom, nitrogen atom and sulfur atom,  
       G 6  is a carbon atom or a nitrogen atom, a broken line in ring A shows a single bond or a double bond,  
       R 1  is  
       (1) a carboxyl group,  
       (2) a carboxylic acid equivalent,  
       (3) —CONR 11 R 12    
       (wherein R 11  and R 12  are each independently  
       (1′) a hydrogen atom,  
       (2′) a C 1-6  alkyl group optionally substituted by 1 to 3 substituents selected from the following group E,  
       (3′) a C 2-6  alkenyl group optionally substituted by 1 to 3 substituents selected from the following group E,  
       (4′) a C 6-14  aryl group optionally substituted by 1 to 5 substituents selected from the following group E,  
       (5′) a heterocyclic group optionally substituted by 1 to 5 substituents selected from the following group E  
       (wherein said heterocyclic group comprises 1 to 4 heteroatoms selected from oxygen atom, nitrogen atom and sulfur atom),  
       (6′) a C 3-10  cycloalkyl group optionally substituted by 1 to 5 substituents selected from the following group E,  
       (7′) —NR 131 R 132    
       (8′) —NHCOOR 133 ,  
       (9′) —NHCOR 134    
       (wherein R 131 , R 132 , R 133  and R 134  are each independently a hydrogen atom or a group selected from the following group F),  
       (10′) —CR 135 R 136 -L 100 -R 137 ,  
       (11′) —CR 135 R 136 -L 100 -CONR 140 —R 137 ,  
       
         
           
           
               
               
           
         
       
       (wherein R 135 , R 136 , R 138  and R 139  are each independently  
       (1″) a hydrogen atom or  
       (2″) a group selected from the following group G,  
       group G:  
       (1′″) cyano group,  
       (2′″) —COOR 142    
       (wherein R 142  is a hydrogen atom or a group selected from the following group F)  
       (3′″) —CONR 143 R 144    
       (wherein R 143  and R 144  are each independently a hydrogen atom, a C 1-6  alkoxy group or a group selected from the following group F)  
       (4′″) a C 1-6  alkyl group optionally substituted by 1 to 3 substituents selected from the following group A,  
       (5′″) a C 2-6  alkenyl group optionally substituted by 1 to 3 substituents selected from the following group A,  
       (6′″) a C 6-14  aryl group optionally substituted by 1 to 5 substituents selected from the following group B,  
       (7′″) a heterocyclic group optionally substituted by 1 to 5 substituents selected from the following group B  
       (wherein said heterocyclic group comprises 1 to 4 heteroatoms selected from oxygen atom, nitrogen atom and sulfur atom),  
       (8′″) a C 3-10  cycloalkyl group optionally substituted by 1 to 5 substituents selected from the following group B,  
       (9′″) a C 6-14  aryl C 1-6  alkyl group optionally substituted by 1 to 5 substituents selected from the following group B,  
       (10′″) a heterocycle C 1-6  alkyl group optionally substituted by 1 to 5 substituents selected from the following group B and  
       (11′″) a C 3-10  cycloalkyl C 1-6  alkyl group optionally substituted by 1 to 5 substituents selected from the following group B; or  
       R 135  and R 136 , or, R 138  and R 139  are bonded to each other, and optionally form, together with the carbon atom bonded thereto,  
       (1″) a C 3-10  cycloalkyl group optionally substituted by 1 to 5 substituents selected from the following group B or  
       (2″) a heterocyclic group optionally substituted by 1 to 5 substituents selected from the following group B  
       (wherein said heterocyclic group comprises 1 to 4 heteroatoms selected from oxygen atom, nitrogen atom and sulfur atom),  
       R 137  is  
       (1″) a hydrogen atom,  
       (2″) a carboxyl group,  
       (3″) a C 1-6  alkyl group optionally substituted by 1 to 3 substituents selected from the following group E,  
       (4″) a C 2-6  alkenyl group optionally substituted by 1 to 3 substituents selected from the following group E,  
       (5″) a C 6-14  aryl group optionally substituted by 1 to 5 substituents selected from the following group E,  
       (6″) a heterocyclic group optionally substituted by 1 to 5 substituents selected from the following group E  
       (wherein said heterocyclic group comprises 1 to 4 heteroatoms selected from oxygen atom, nitrogen atom and sulfur atom) or  
       (7″) a C 3-10  cycloalkyl group optionally substituted by 1 to 5 substituents selected from the following group E,  
       R 140  and R 141  are each independently  
       (1″) a hydrogen atom or  
       (2″) a C 1-6  alkyl group,  
       L 100  is  
       (1″) a bond,  
       (2″) —CO—,  
       (3″) —CH 2 O—,  
       (4″) —CH 2 NH—,  
       (5″) —CH 2 NHCO—,  
       (6″) a C 1-6  alkylene optionally substituted by hydroxyl group or  
       (7″) a C 2-6  alkenylene,  
       L 101  and L 102  are each independently  
       (1″) a bond,  
       (2″) —CO—,  
       (3″) a C 1-6  alkylene optionally substituted by hydroxyl group or  
       (4″) a C 2-6  alkenylene,  
       L 103  is  
       (1″) a bond or  
       (2″) a C 1-6  alkylene,  
       L 104  is a C 1-6  alkylene,  
       L 105  is  
       (1″) a bond or  
       (2″) a C 1-6  alkylene,  
       L 106  is  
       (1″) a bond,  
       (2″) a C 1-6  alkylene,  
       (3″) —NH—,  
       (4″) —NH—CH 2 — or  
       (5″) —CH 2 —CONH—,  
       ring D 3 , ring D 4  and ring D 5  are each independently  
       (1″) a C 6-14  aryl group optionally substituted by 1 to 5 substituents selected from the following group E,  
       (2″) a C 3-10  cycloalkyl group optionally substituted by 1 to 5 substituents selected from the following group E or  
       (3″) a heterocyclic group optionally substituted by 1 to 5 substituents selected from the following group E  
       (wherein said heterocyclic group comprises 1 to 4 heteroatoms selected from oxygen atom, nitrogen atom and sulfur atom))),  
       (4) —COOR 103    
       (wherein R 103  is a group selected from the following group C or a glucuronic acid residue),  
       
         
           
           
               
               
           
         
       
       (wherein ring D 6  is a heterocyclic group optionally substituted by 1 to 5 substituents selected from the following group E  
       (wherein said heterocyclic group comprises 1 to 4 heteroatoms selected from oxygen atom, nitrogen atom and sulfur atom),  
       ring D 7  is a C 6-14  aryl group optionally substituted by 1 to 5 substituents selected from the following group E),  
       R 2  may substitute at a substitutable position on carbon atom or nitrogen atom constituting Q and is  
       (1) a hydrogen atom,  
       (2) a group selected from the following group E,  
       (3) a C 1-6  alkyl group optionally substituted by 1 to 3 substituents selected from the following group E,  
       (4) a C 2-6  alkenyl group optionally substituted by 1 to 3 substituents selected from the following group E,  
       
         
           
           
               
               
           
         
       
       {wherein L 1  and L 2  are each independently  
       (1′) a bond,  
       (2′) C 1-6  alkylene,  
       (3′) C 2-6  alkenylene,  
       (4′) —(CH 2 ) u1 —O—(CH 2 ) v1 —,  
       (5′) —(CH 2 ) u1 —S—(CH 2 ) v1 —,  
       (6′) —(CH 2 ) u1 —NR L1 —(CH 2 ) v1 —,  
       (7′) —(CH 2 ) u1 —CO—(CH 2 ) v1 —,  
       (8′) —(CH 2 ) u1 —CONR L2 —(CH 2 ) v1 —,  
       (9′) —(CH 2 ) u1 —NR L2 CO 2 —(CH 2 ) v1 —,  
       (10′) —(CH 2 ) u1 —NR L2 CONR L3 —(CH 2 ) v1 —,  
       (11′) —(CH 2 ) u1 —NR L2 CO—(CH 2 ) v1 —,  
       (12′) —(CH 2 ) u1 —NR L2 SO 2 —(CH 2 ) v1 —,  
       (13′) —(CH 2 ) u1 —SO 2 —(CH 2 ) v1 —,  
       (14′) —(CH 2 ) u1 —SO 2 NR L2 —(CH 2 ) v1 — or  
       (15′) —(CH 2 ) u1 —N + R L2 R L2′ —(CH 2 ) v1 —,  
       (wherein u, v, u1 and v1 are each independently 0 or an integer of 1 to 6,  
       R L1  is  
       (1″) a hydrogen atom,  
       (2″) a group selected from the following group C,  
       (3″) —COR L11 ,  
       (4″) —CONR L11 R L12 ,  
       (5″) —COOR L11  or  
       (6″) —SO 2 R L13    
       (wherein R L11  and R L12  are each independently a hydrogen atom or a group selected from the following group C, and R L13  is a group selected from the following group C),  
       R L2 , R L2  and R L3  are each independently  
       (1″) a hydrogen atom,  
       (2″) a group selected from the following group C,  
       (3″) —COR L11  or  
       (4″) —SO 2 R L13    
       (wherein R L11  and R L13  are as defined above)),  
       L 3  is  
       (1′) —CHR L14 — or  
       (2′) —NR L14 — 
       (wherein R L14  is a group selected from the following group F),  
       ring D 1  and ring D 2  are each independently  
       (1′) a C 6-14  aryl group optionally substituted by 1 to 5 substituents selected from the following group E,  
       (2′) a C 3-10  cycloalkyl group optionally substituted by 1 to 5 substituents selected from the following group E or  
       (3′) a heterocyclic group optionally substituted by 1 to 5 substituents selected from the following group E  
       (wherein said heterocyclic group comprises 1 to 4 heteroatoms selected from oxygen atom, nitrogen atom and sulfur atom)},  
       R 3  is  
       (1) a hydrogen atom,  
       (2) a halogen atom,  
       (3) a C 1-6  alkanoyl group,  
       (4) a carboxyl group,  
       (5) a cyano group,  
       (6) a nitro group,  
       (7) a C 1-6  alkyl group optionally substituted by 1 to 3 substituents selected from the following group A,  
       (8) —OR 101    
       (wherein R 101  is a hydrogen atom or a group selected from the following group C),  
       (9) —NR 102 R 119    
       (wherein R 102  and R 119  are each independently a hydrogen atom, a C 1-6  alkanoyl group or a C 1-6  alkylsulfonyl group),  
       (10) —COOR 103    
       (wherein R 103  is a group selected from the following group C or a glucuronic acid residue),  
       (1) —CONR 104 R 105    
       (wherein R 104  and R 105  are each independently a hydrogen atom, a hydroxyl group, a cyano group, a C 1-6  alkoxy group or a C 1-6  alkyl group optionally substituted by 1 to 3 substituents selected from the following group A),  
       (12) —SO 2 R 106    
       (wherein R 106  is a hydroxyl group, an amino group, a C 1-6  alkyl group or a C 1-6  alkylamino group),  
       (13) —NHCOR 107    
       (wherein R 107  is an amino group or a C 1-6  alkylamino group),  
       (14) —C(═NR 108 )—NH 2    
       (wherein R 108  is a hydrogen atom, a C 1-6  alkyl group optionally substituted by 1 to 3 substituents selected from the following group A, a hydroxyl group or a C 1-6  alkoxy group),  
       (15) —P(═O)(OR 109 ) 2    
       (wherein R 109  are each independently a hydrogen atom or a group selected from the following group C),  
       (16) —P(═O)(OR 110 )NR 111 R 112    
       (wherein R 110 , R 111  and R 112  are each independently a hydrogen atom or a group selected from the following group C),  
       (17) —CONHCO—R 113    
       (wherein R 113  is a group selected from the following group C),  
       (18) —CONHSO 2 —R 114    
       (wherein R 114  is a group selected from the following group C),  
       (19) —SO 2 NHCO—R 115    
       (wherein R 115  is a group selected from the following group C) or  
       (20) a heterocyclic group optionally substituted by 1 to 5 substituents selected from the following group B  
       (wherein said heterocyclic group comprises 1 to 4 heteroatoms selected from oxygen atom, nitrogen atom and sulfur atom),  
       R 4  may substitute at a substitutable position on carbon atom or nitrogen atom constituting Q and each is independently  
       (1) a halogen atom,  
       (2) a C 1-6  alkyl group optionally substituted by 1 to 3 substituents selected from the following group A,  
       (3) —OR 116    
       (wherein R 116  is a hydrogen atom or a group selected from the following group C),  
       (4) —NR 117 R 118    
       (wherein R 117  and R 118  are each independently a hydrogen atom, a C 1-6  alkanoyl group or a group selected from the following group C),  
       (5) a C 6-14  aryl group optionally substituted by 1 to 5 substituents selected from the following group B or  
       (6) a heterocyclic group optionally substituted by 1 to 5 substituents selected from the following group B  
       (wherein said heterocyclic group comprises 1 to 4 heteroatoms selected from oxygen atom, nitrogen atom and sulfur atom),  
       a is 0, 1 or 2,  
       R 5  and R 6  are each independently  
       (1) a hydrogen atom,  
       (2) a halogen atom,  
       (3) a C 1-6  alkyl group optionally substituted by 1 to 3 substituents selected from the following group A,  
       (4) —OR 120    
       (wherein R 120  is a hydrogen atom or a group selected from the following group C) or  
       (5) —NR 121 R 122    
       (wherein R 121  and R 122  are each independently a hydrogen atom, a C 1-6  alkanoyl group or a group selected from the following group C),  
       ring Cy is  
       (1) a C 3-10  cycloalkyl group optionally substituted by 1 to 5 substituents selected from the following group B,  
       (2) a C 3-10  cycloalkenyl group optionally substituted by 1 to 5 substituents selected from the following group B or  
       (3) a heterocyclic group optionally substituted by 1 to 5 substituents selected from the following group B  
       (wherein said heterocyclic group comprises 1 to 4 heteroatoms selected from oxygen atom, nitrogen atom and sulfur atom),  
       X is  
       (1) a group selected from the following group D,  
       (2) a C 2-6  alkenyl group optionally substituted by 1 to 3 substituents selected from the following group A or  
       
         
           
           
               
               
           
         
       
       wherein ring B is  
       (1′) a C 6-14  aryl group,  
       (2′) a C 3-10  cycloalkyl group or  
       (3′) a heterocyclic group comprising 1 to 4 heteroatoms selected from oxygen atom, nitrogen atom and sulfur atom,  
       each Z is independently  
       (1′) a group selected from the following group D,  
       (2′) a C 6-14  aryl group optionally substituted by 1 to 5 substituents selected from the following group D,  
       (3′) a C 3-10  cycloalkyl group optionally substituted by 1 to 5 substituents selected from the following group D,  
       (4′) a C 6-14  aryl C 1-6  alkyl group optionally substituted by 1 to 5 substituents selected from the following group D,  
       (5′) a heterocyclic group optionally substituted by 1 to 5 substituents selected from the following group D  
       (wherein said heterocyclic group comprises 1 to 4 heteroatoms selected from oxygen atom, nitrogen atom and sulfur atom) or  
       (6′) a heterocycle C 1-6  alkyl group optionally substituted by 1 to 5 substituents selected from the following group D  
       (wherein said heterocycle C 1-6  alkyl group is a C 1-6  alkyl group substituted by “a heterocyclic group optionally substituted by 1 to 5 substituents selected from group D” as defined above),  
       w is an integer of 1 to 3,  
       Y is  
       (a) C 1-6  alkylene,  
       (b) C 2-6  alkenylene or  
       (c) —Y 1 —(CH 2 ) m —Y 2 —(CH 2 ) n — 
       (wherein m and n are each independently 0 or an integer of 1 to 6,  
       Y 1  and Y 2  are each independently  
       (1′) a bond,  
       (2′) —O—,  
       (3′) —NR y1 —,  
       (4′) —S—,  
       (5′) —CO—,  
       (6′) —SO—,  
       (7′) —SO 2 —,  
       (8′) —CO 2 —,  
       (9′) —OCO—,  
       (10′) —CONR y2 —,  
       (11′) —NR y2 CO—,  
       (12′) —SO 2 NR y2 —,  
       (13′) —NR y2 SO 2 —,  
       (14′) —NR 2 CO 2 —,  
       (15′) —OCONR y2 —,  
       (16′) —NR y2 CONR y3 —,  
       (17′) —CR y4 R y5 — or  
       (18′) —CH═CH— 
       (wherein R y1  is  
       (1″) a hydrogen atom,  
       (2″) a group selected from the following group C,  
       (3″) —(CH 2 ) s —COOR y11 ,  
       (4″) —(CH 2 ) s —CONR y11 R y12 ,  
       (5″) —(CH 2 ) s —COR y11  or  
       (6″) —(CH 2 ) s —SO 2 R y13    
       (wherein s is 0 or an integer of 1 to 6, R y11  and R y12  are each independently a hydrogen atom or a group selected from the following group C, and R y13  is a group selected from the following group C),  
       R y2  and R y3  are each independently  
       (1″) a hydrogen atom,  
       (2″) a group selected from the following group C,  
       (3″) —COR y11  or  
       (4″) —SO 2 R y13  (wherein R y11  and R y13  are as defined above),  
       R y4  and R y5  are each independently  
       (1″) a hydrogen atom,  
       (2″) a carboxyl group,  
       (3″) a group selected from group F,  
       (4″) —OR y14  or  
       (5″) —NHR y15    
       (wherein R y14  is a group selected from the following group C, R y15  is a hydrogen atom, a C 1-6  alkyl group, a C 1-6  alkanoyl group, a C 6-14  aryl C 1-6  alkyloxycarbonyl group or a C 1-6  alkoxycarbonyl group)))  
       group A:  
       (1) a halogen atom,  
       (2) a C 1-6  alkoxy C 1-6  alkoxy group,  
       (3) a cyano group,  
       (4) —OR a1 ,  
       (5) —SR a1 ,  
       (6) —NR a1 R a2 ,  
       (7) —COOR a1 ,  
       (8) —CONR a1 R a2 ,  
       (9) —SO 3 H,  
       (10) —SO 2 NR a1 R a2 ,  
       (11) —NHCOR a1 ,  
       (12) —NHSO 2 R a3 ,  
       (13) —NHCO 2 R a4 ,  
       (14) —COR a1  and  
       (15) —N + R a1 R a2 R a3    
       (wherein R a1  and R a2  are each a hydrogen atom, a C 1-6  alkyl group or a benzyl group, R a3  is a C 1-6  alkyl group and R a4  is a C 1-6  alkyl group)  
       group B:  
       (1) a halogen atom,  
       (2) a cyano group,  
       (3) a nitro group,  
       (4) a C 1-6  alkyl group,  
       (5) a C 2-6  alkenyl group optionally substituted by carboxyl group,  
       (6) a halogenated C 1-6  alkyl group,  
       (7) —(CH 2 ) r —OR b1 ,  
       (8) —(CH 2 ) r —SR b1 ,  
       (9) —(CH 2 ) r —NR b1 R b2 ,  
       (10) —(CH 2 ) r —COOR b1 ,  
       (11) —(CH 2 ) r —CONR b1 R b2 ,  
       (12) —(CH 2 ) r —COR b1 ,  
       (13) —(CH 2 ) r —NR b1 —COR b2 ,  
       (14) —(CH 2 ) r —NR b1 —SO 2 R b3 ,  
       (15) —(CH 2 ) r —SO 2 R b3 ,  
       (16) —(CH 2 ) r —SO 2 NR b1 R b2 ,  
       (17) —(CH 2 ) r —CONR b1 —SO 2 R b3 ,  
       (18) —(CH 2 ) r —SO 2 NR b1 —COR b2 ,  
       (19) —(CH 2 ) r —NR b1 —COOR b3 ,  
       (20) —(CH 2 ) r —NR b1 —CONR b2 R b4 ,  
       (21) —O—(CH 2 ) r —COOR b1  and  
       (22) —CO—(CH 2 ) r —R b5    
       (wherein R b1 , R b2  and R b4  are each independently a hydrogen atom or a C 1-6  alkyl group, R b3  is a C 1-6  alkyl group, R b5  is a heterocyclic group and r is 0 or an integer of 1 to 6)  
       group C:  
       (1) a C 1-6  alkyl group optionally substituted by 1 to 3 substituents selected from the aforementioned group A,  
       (2) a C 6-14  aryl group optionally substituted by 1 to 5 substituents selected from the aforementioned group B,  
       (3) a C 6-14  aryl C 1-6  alkyl group optionally substituted by 1 to 5 substituents selected from the aforementioned group B,  
       (4) a heterocyclic group optionally substituted by 1 to 5 substituents selected from the aforementioned group B and  
       (5) a heterocycle C 1-6  alkyl group optionally substituted by 1 to 5 substituents selected from the aforementioned group B  
       group D:  
       (a) a hydrogen atom,  
       (b) a halogen atom,  
       (c) a cyano group,  
       (d) a nitro group,  
       (e) a C 1-6  alkyl group optionally substituted by 1 to 3 substituents selected from the aforementioned group A,  
       (f) —(CH 2 ) t —OR d1 ,  
       wherein R d1  is  
       (1) a hydrogen atom,  
       (2) a group selected from the following group F,  
       (3) a C 2-6  alkenyl group optionally substituted by 1 to 3 substituents selected from the aforementioned group A or  
       (4) a C 2-6  alkynyl group optionally substituted by 1 to 3 substituents selected from the aforementioned group A,  
       hereinafter each t is independently 0 or an integer of 1 to 6,  
       (g) —(CH 2 ) t —S(O) q —R d2 ,  
       wherein R d2  is  
       (1) a hydrogen atom or  
       (2) a group selected from the following group F,  
       q is 0, 1, 2 or 3,  
       (h) —(CH 2 ) t —NR d3 R d4 ,  
       wherein R d3  and R d4  are each independently  
       (1) a hydrogen atom or  
       (2) a group selected from the following group F,  
       (i) —(CH 2 ) t —COOR d5 ,  
       wherein R d5  is  
       (1) a hydrogen atom or  
       (2) a group selected from the following group F,  
       (j) —(CH 2 ) t —CONR d6 R d7 ,  
       wherein R d6  and R d7  are each independently  
       (1) a hydrogen atom,  
       (2) a hydroxyl group,  
       (3) a group selected from the following group F or  
       (4) a C 1-6  alkoxy group,  
       (k) —(CH 2 ) t —COR d8 ,  
       wherein R d8  is  
       (1) a hydrogen atom or  
       (2) a group selected from the following group F,  
       (1) —(CH 2 ) t —NR d9 CO—R d10 ,  
       wherein R d9  is  
       (1) a hydrogen atom,  
       (2) a C 1-6  alkyl group optionally substituted by 1 to 3 substituents selected from the aforementioned group A or  
       (3) a C 1-6  alkanoyl group,  
       R d10  is  
       (1) an amino group,  
       (2) a C 1-6  alkylamino group or  
       (3) a group selected from the following group F,  
       (m) —(CH 2 ) t —NR d11 SO 2 —R d12 ,  
       wherein R d11  is  
       (1) a hydrogen atom,  
       (2) a C 1-6  alkyl group optionally substituted by 1 to 3 substituents selected from the aforementioned group A or  
       (3) a C 1-6  alkanoyl group,  
       R d12  is  
       (1) a hydrogen atom or  
       (2) a group selected from the following group F,  
       (n) —(CH 2 ) t —SO 2 —NR d13 R d14 ,  
       wherein R d13  and R d14  are each independently  
       (1) a hydrogen atom or  
       (2) a group selected from the following group F,  
       (o) —(CH 2 ) t —CONR d15 —SO 2 R d16 ,  
       wherein R d15  and R d16  are each independently  
       (1) a hydrogen atom or  
       (2) a group selected from the following group F,  
       (p) —(CH 2 ) t —SO 2 NR d17 —COR d18 ,  
       wherein R d17  is  
       (1) a hydrogen atom or  
       (2) a group selected from the following group F,  
       R d18  is a group selected from the following group F,  
       (q) —(CH 2 ) t —NR d19 —COOR d20 ,  
       wherein R d19  and R d20  are each independently  
       (1) a hydrogen atom or  
       (2) a group selected from the following group F,  
       (r) —(CH 2 ) t —NR d21 —CONR d22 R d23 ,  
       wherein R d21 , R d22  and R d23  are each independently  
       (1) a hydrogen atom or  
       (2) a group selected from the following group F,  
       (s) —(CH 2 ) t —C(═NR d24 )NH 2 ,  
       wherein R d24  is  
       (1) a hydrogen atom,  
       (2) a hydroxyl group,  
       (3) a C 1-6  alkyl group optionally substituted by 1 to 3 substituents selected from the aforementioned group A or  
       (4) C 1-6  alkoxy group,  
       (t) —(CH 2 ) t —O—(CH 2 ) p —COR d25 ,  
       wherein R d25  is  
       (1) an amino group,  
       (2) a C 1-6  alkylamino group or  
       (3) a heterocyclic group optionally substituted by 1 to 5 substituents selected from the aforementioned group B,  
       p is 0 or an integer of 1 to 6,  
       (u) —(CH 2 ) t —O—(CH 2 ) p —NR d26 R d27 ,  
       wherein R d26  and R d27  are each independently  
       (1) a hydrogen atom or  
       (2) a C 1-6  alkyl group optionally substituted by 1 to 3 substituents selected from the aforementioned group A,  
       p is 0 or an integer of 1 to 6,  
       (v) —(CH 2 ) t —O—COOR d28 ,  
       wherein R d28  is  
       (1) a hydrogen atom or  
       (2) a group selected from the following group F, and  
       (w) a heterocyclic group optionally substituted by 1 to 5 substituents selected from the aforementioned group B  
       (wherein said heterocyclic group comprises 1 to 4 heteroatoms selected from oxygen atom, nitrogen atom and sulfur atom)  
       group E:  
       (a) a halogen atom,  
       (b) a cyano group,  
       (c) a nitro group,  
       (d) an azido group,  
       (e) —OP(═O)(OH) 2 ,  
       (f) —OR e1 ,  
       wherein R e1  is  
       (1) a hydrogen atom,  
       (2) a group selected from the following group F,  
       (3) a C 2-6  alkenyl group optionally substituted by 1 to 3 substituents selected from the aforementioned group A or  
       (4) a C 2-6  alkynyl group optionally substituted by 1 to 3 substituents selected from the aforementioned group A,  
       (g) —S(O) q —R e2    
       wherein R e2  is  
       (1) a hydrogen atom or  
       (2) a group selected from the following group F,  
       q is 0, 1, 2 or 3,  
       (h) NR e3 R e4 ,  
       wherein R e3  and R e4  are each independently  
       (1) a hydrogen atom,  
       (2) a cyano group or  
       (3) a group selected from the following group F,  
       (i) —COOR e5 ,  
       wherein R e5  is  
       (1) a hydrogen atom or  
       (2) a group selected from the following group F,  
       (j) —CONR e6 R e7 ,  
       wherein R e6  and R e7  are each independently  
       (1) a hydrogen atom,  
       (2) a hydroxyl group,  
       (3) a group selected from the following group F or  
       (4) a C 1-6  alkoxy group,  
       (k) —COR e8 ,  
       wherein R e8  is a group selected from the following group F,  
       (1) —NR e9 CO—R e10 ,  
       wherein R e9  is  
       (1) a hydrogen atom,  
       (2) a C 1-6  alkyl group or  
       (3) a C 1-6  alkanoyl group,  
       R e10  is  
       (1) a hydrogen atom,  
       (2) an amino group,  
       (3) a C 1-6  alkylamino group,  
       (4) a C 2-6  alkenyl group optionally substituted by 1 to 3 substituents selected from the aforementioned group A or  
       (5) a group selected from the following group F,  
       (m) —NR e11 SO 2 —R e12 ,  
       wherein R e11  is  
       (1) a hydrogen atom,  
       (2) a C 1-6  alkyl group or  
       (3) a C 1-6  alkanoyl group,  
       R e12  is  
       (1) a hydrogen atom or  
       (2) a group selected from the following group F,  
       (n) —SO 2 —NR e13 R e14 ,  
       wherein R e13  and R e14  are each independently  
       (1) a hydrogen atom or  
       (2) a group selected from the following group F,  
       (o) —CONR e15 —SO 2 R 16 ,  
       wherein R e15  and R e16  are each independently  
       (1) a hydrogen atom or  
       (2) a group selected from the following group F,  
       (p) —SO 2 NR e17 —COR e18 ,  
       wherein R e17  is  
       (1) a hydrogen atom or  
       (2) a group selected from the following group F,  
       R e18  is a group selected from the following group F,  
       (q) NR e19 —COOR e20 ,  
       wherein R e19  and R e20  are each independently  
       (1) a hydrogen atom or  
       (2) a group selected from the following group F,  
       (r) —NR e21 —CONR e22 R e23    
       wherein R e21 , R e22  and R e23  are each independently  
       (1) a hydrogen atom or  
       (2) a group selected from the following group F,  
       (s) —NHCO—COOR e24    
       wherein R e24  is  
       (1) a hydrogen atom or  
       (2) a group selected from the following group F,  
       (t) —NHCO—CONR e25 R e26    
       wherein R e25  and R e26  are each independently  
       (1) a hydrogen atom,  
       (2) a hydroxyl group or  
       (3) a group selected from the following group F,  
       (u) —CONH—COOH,  
       
         
           
           
               
               
           
         
       
       (y) a C 6-14  aryl group optionally substituted by 1 to 5 substituents selected from the aforementioned group B,  
       (z) a C 3-10  cycloalkyl group optionally substituted by 1 to 5 substituents selected from the aforementioned group B,  
       (aa) a heterocyclic group optionally substituted by 1 to 5 substituents selected from the aforementioned group B  
       (wherein said heterocyclic group comprises 1 to 4 heteroatoms selected from oxygen atom, nitrogen atom and sulfur atom),  
       (bb) a C 3-10  cycloalkylidene group optionally substituted by 1 to 5 substituents selected from the aforementioned group B, and  
       (cc) a heterocycle ylidene group optionally substituted by 1 to 5 substituents selected from the aforementioned group B  
       (wherein said heterocycle ylidene group comprises 1 to 4 heteroatoms selected from oxygen atom, nitrogen atom and sulfur atom),  
       when group E is a substituent on a C 6-14  aryl group, a C 3-10  cycloalkyl group or a heterocyclic group, it may be  
       (dd) a C 1-6  alkyl group optionally substituted by 1 to 3 substituents selected from the aforementioned group A,  
       (ee) a C 2-6  alkenyl group optionally substituted by 1 to 3 substituents selected from the aforementioned group A,  
       (ff) a C 2-6  alkynyl group optionally substituted by 1 to 3 substituents selected from the aforementioned group A,  
       (gg) C 1-6  alkylidene group optionally substituted by 1 to 3 substituents selected from the aforementioned group A,  
       (hh) a C 6-14  aryl C 1-6  alkyl group optionally substituted by 1 to 5 substituents selected from the aforementioned group B,  
       (ii) a C 3-10  cycloalkyl C 1-6  alkyl group optionally substituted by 1 to 5 substituents selected from the aforementioned group B, or  
       (jj) a heterocycle C 1-6  alkyl group optionally substituted by 1 to 5 substituents selected from the aforementioned group B  
       group F:  
       (1) a C 1-6  alkyl group optionally substituted by 1 to 3 substituents selected from the aforementioned group A,  
       (2) a C 6-14  aryl group optionally substituted by 1 to 5 substituents selected from the aforementioned group B,  
       (3) a heterocyclic group optionally substituted by 1 to 5 substituents selected from the aforementioned group B  
       (wherein said heterocyclic group comprises 1 to 4 heteroatoms selected from oxygen atom, nitrogen atom and sulfur atom),  
       (4) a C 3-10  cycloalkyl group optionally substituted by 1 to 5 substituents selected from the aforementioned group B,  
       (5) a C 6-14  aryl C 1-6  alkyl group optionally substituted by 1 to 5 substituents selected from the aforementioned group B,  
       (6) a heterocycle C 1-6  alkyl group optionally substituted by 1 to 5 substituents selected from the aforementioned group B  
       (wherein said heterocycle C 1-6  alkyl group is a C 1-6  alkyl group substituted by “a heterocyclic group optionally substituted by 1 to 5 substituents selected from group B” as defined above) and  
       (7) a C 3-10  cycloalkyl C 1-6  alkyl group optionally substituted by 1 to 5 substituents selected from the aforementioned group B.  
     
   
   
       2 . The compound of  claim 1 , wherein, in the formula [I],  
                       
G 2 G 1    
     is N—C═C, or a pharmaceutically acceptable salt thereof.  
   
   
       3 . The compound of  claim 1 , wherein, in the formula [I], the moiety  
     
       
         
         
             
             
         
       
     
     is a fused ring selected from the group consisting of  
     
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
     
     or a pharmaceutically acceptable salt thereof.  
   
   
       4 .- 6 . (canceled)  
   
   
       7 . The compound of  claim 1 , wherein G 3 , G 4  and G 5  are carbon atoms, or a pharmaceutically acceptable salt thereof.  
   
   
       8 . The compound of  claim 1 , wherein Q 1  is —O—, —NH—, —S— or —CONH—, or a pharmaceutically acceptable salt thereof.  
   
   
       9 .- 10 . (canceled)  
   
   
       11 . The compound of  claim 1 , wherein Q is —(CH 2 ) 2 —O— or —(CH 2 ) 2 —NH—, or a pharmaceutically acceptable salt thereof.  
   
   
       12 . The compound of  claim 1 , wherein R 1  is a carboxyl group or —CONR 11 R 12 , or a pharmaceutically acceptable salt thereof.  
   
   
       13 .- 29 . (canceled)  
   
   
       30 . The compound of  claim 1 , wherein R 2  is a hydrogen atom, a group selected from group E, a C 1-6  alkyl group optionally substituted by 1 to 3 substituents selected from group E,  
     
       
         
         
             
             
         
       
       wherein each symbol is as defined in  claim 1 , or a pharmaceutically acceptable salt thereof.  
     
   
   
       31 .- 36 . (canceled)  
   
   
       37 . The compound of  claim 1 , wherein R 3  is a hydrogen atom, a halogen atom, a C 1-6  alkyl group optionally substituted by 1 to 3 substituents selected from group A or —OR 101  (wherein R 101  is a hydrogen atom or a group selected from group C), or a pharmaceutically acceptable salt thereof.  
   
   
       38 . The compound of  claim 1 , wherein R 5  and R 6  are each independently a hydrogen atom, a halogen atom, a C 1-6  alkyl group optionally substituted by 1 to 3 substituents selected from group A or —OR 120  (wherein R 120  is a hydrogen atom or a group selected from group C), or a pharmaceutically acceptable salt thereof.  
   
   
       39 . The compound of  claim 1 , wherein ring A is benzene or a 5- or 6-membered heterocycle comprising 1 to 4 heteroatoms selected from oxygen atom, nitrogen atom and sulfur atom, or a pharmaceutically acceptable salt thereof.  
   
   
       40 . (canceled)  
   
   
       41 . The compound of  claim 1 , wherein ring Cy is a C 3-10  cycloalkyl group or a C 3-10  cycloalkenyl group, or a pharmaceutically acceptable salt thereof.  
   
   
       42 . (canceled)  
   
   
       43 . The compound of  claim 1 , wherein X is a hydrogen atom, a halogen atom, a C 1-6  alkyl group optionally substituted by 1 to 3 substituents selected from group A, —(CH 2 ) t —OR d1 , —(CH 2 ) t —S(O) q —R d2 , —(CH 2 ) t —NR d3 R d4  or  
     
       
         
         
             
             
         
       
       wherein each symbol is as defined in  claim 1 , or a pharmaceutically acceptable salt thereof.  
     
   
   
       44 .- 49 . (canceled)  
   
   
       50 . The compound of  claim 1 , which is represented by the following formula [I-A], or a pharmaceutically acceptable salt thereof:  
     
       
         
         
             
             
         
       
       wherein X′ is a hydrogen atom, a halogen atom, a C 1-6  alkyl group optionally substituted by 1 to 3 substituents selected from group A or —OR d1 , and other symbols are as defined in  claim 1 .  
     
   
   
       51 . The compound of  claim 1 , which is represented by the following formula [I-B], or a pharmaceutically acceptable salt thereof:  
     
       
         
         
             
             
         
       
       wherein Q 2  is —O— or —NH—, and other symbols are as defined in  claim 1 .  
     
   
   
       52 . The compound of  claim 1 , which is represented by the following formula [I-C], or a pharmaceutically acceptable salt thereof:  
     
       
         
         
             
             
         
       
       wherein Q 3  is —O— or —NR 2 —, X′ is a hydrogen atom, a halogen atom, a C 1-6  alkyl group optionally substituted by 1 to 3 substituents selected from group A or —OR d1 , and other symbols are as defined in  claim 1 .  
     
   
   
       53 . A composition comprising a compound of  claim 1  and a pharmaceutically acceptable carrier.  
   
   
       54 .- 64 . (canceled)  
   
   
       65 . A method for treating hepatitis C, which comprises administering an effective amount of a compound of  claim 1  to a mammal.  
   
   
       66 . The method of  claim 65 , further comprising administering an effective amount of at least one pharmaceutical agent selected from the group consisting of a different antiviral agent, an antiinflammatory agent and an immunostimulant to the mammal.  
   
   
       67 . The method of  claim 65 , further comprising administering an effective amount of interferon to the mammal.  
   
   
       68 . A method for inhibiting hepatitis C virus polymerase, which comprises administering an effective amount of a compound of  claim 1  to a mammal.  
   
   
       69 . The method of  claim 68 , further comprising administering an effective amount of at least one pharmaceutical agent selected from the group consisting of a different antiviral agent, an antiinflammatory agent and an immunostimulant to the mammal.  
   
   
       70 . The method of  claim 68 , further comprising administering an effective amount of interferon to the mammal.