PYRIDAZINONE DERIVATIVESA pyridazinone derivative represented by formula (I) :  {wherein R1 represents a phenyl group, a substituted phenyl group, an aromatic heterocyclic group or a substituted aromatic heterocyclic group; R2 represents a (C1 -C8 )alkyl group, a substituted (C1 -C8 )alkyl group, a phenyl group, a substituted phenyl group, an aralkyl group, a substituted aralkyl group, an aromatic heterocyclic group, a substituted aromatic heterocyclic group, an amino group, an amino group substituted with one or two (C1 -C8 )alkyl groups which are the same or different, a 4- to 10-membered cyclic amino group, a cyano group, a carboxyl group, a (C1 -C8 )alkoxyearbonyl group, a carbamoyl group, a thiocarbamoyl group, an aminocarbonyl group, an aminocarbonyl group substituted with one or two (C1 -C8 )alkyl groups or substituted (C1 -C8 )alkyl groups which are the same or different, a 4- to 10-membered cyclic aminocarbonyl group, a phenylaminocarbonyl group, a substituted phenylaminocarbonyl group, an aromatic heterocyle-aminocarbonyl group or a substituted aromatic heterocyle-aminocarbonyl group; R3 represents a hydrogen atom, a (C1 -C8 )alkyl group, a substituted (C1 -C8 )alkyl group, a phenyl group, a substituted phenyl group, an aromatic heterocyclic group or a substituted aromatic heterocyclic group; and R4 represents a cyano group,  a pharmaceutically acceptable salt thereof, or a derivative thereof, or a pharmaceutical composition comprising as an active ingredient the derivative or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable carrier or diluent. A pyridazinone derivative represented by formula (I):{wherein R1 represents a phenyl group, a substituted phenyl group, an aromatic heterocyclic group or a substituted aromatic heterocyclic group;R2 represents a (C1 -C8 )alkyl group, a substituted (C1 -C8 )alkyl group, a phenyl group, a substituted phenyl group, an aralkyl group, a substituted aralkyl group, an aromatic heterocyclic group, a substituted aromatic heterocyclic group, an amino group, an amino group substituted with one or two (C1 -C8 )alkyl groups which are the same or different, a 4- to 10-membered cyclic amino group, a cyano group, a carboxyl group, a (C1 -C8 )alkoxycarbonyl group, a carbamoyl group, a thiocarbamoyl group, an aminocarbonyl group, an aminocarbonyl group substituted with one or two (C1 -C8 )alkyl groups or substituted (C1 -C8 )alkyl groups which are the same or different, a 4- to 10-membered cyclic aminocarbonyl group, a phenylaminocarbonyl group, a substituted phenylaminocarbonyl group, an aromatic heterocyle-aminocarbonyl group or a substituted aromatic heterocyle-aminocarbonyl group;R3 represents a hydrogen atom, a (C1 -C8 )alkyl group, a substituted (C1 -C8 )alkyl group, a phenyl group, a substituted phenyl group, an aromatic heterocyclic group or a substituted aromatic heterocyclic group;R4 represents a cyano group, (wherein R5 represents a hydrogen atom, a (C1 -C8 )alkyl group, a substituted (C1 -C8 )alkyl group, a (C1 -C8 )alkoxy group, a hydroxyl group, amino group, an amino group substituted with one or two (C1 -C8 )alkyl groups which are the same or different, a 4- to 10-membered cyclic amino group, phenyl group, a substituted phenyl group, an aromatic heterocyclic group or a substituted aromatic heterocyclic group, or R5 may form (CR7 2 )m (wherein R7 are the same or different and represents hydrogen atom, a (C1 -C8 )alkyl group, a substituted (C1 -C8 )alkyl group, a phenyl group, a substituted phenyl group, an aromatic heterocyclic group or a substituted aromatic heterocyclic group, and m represent an integer of 2 to 7) together with R3 to form a ring; andY represents NH, O or S), (wherein R6 represents a hydrogen atom, a (C1 -C8 )alkyl group, a substituted (C1 -C8 )alkyl group, a phenyl group, a substituted phenyl group, an aromatic heterocyclic group or a substituted aromatic heterocyclic group, or R6 may form (CR7 2 )m (wherein R7 and m have the same meanings as described above) together with R3 to form a ring; andR8 represents a hydrogen atom or a (C1 -C8 )alkylcarbonyl group), or (wherein R6 has the same meaning as described above; andR9 and R10 are the same or different and represent a (C1 -C8 )alkyl group or a substituted (C1 -C8 )alkyl group, or R9 and R10 together form a (C2 -C4 )alkylene chain and may form a ring together with the atoms attached thereto); andX represents a single bond, O or S(O)n (wherein n represents an integer of 0, 1 or 2)},a pharmaceutically acceptable salt thereof, or a derivative thereof. 
피리다지논 유도체본 발명은 화학식 Ⅰ의 피리다지논 유도체 또는 의약적으로 허용되는 이의 염 및 이를 활성 성분으로서 함유하는 의약 조성물에 관한 것이다. 화학식 Ⅰ  위의 화학식 Ⅰ에서 R1은 임의로 치환된 페닐기 또는 방향족 복소환기이며, R2는 임의로 치환된 알킬기, 페닐기, 아르알킬기, 방향족 복소환기, 아미노기, 환상 아미노기, 시아노기, 카복실기 등이며, R3은 수소원자, 임의로 치환된 알킬기, 페닐기, 방향족 복소환기이며, R4는 시아노기, 카보닐기 등이다. 화학식 Ⅰ의 피리다지논 유도체 또는 의약적으로 허용되는 이의 염 및 유도체. 화학식 Ⅰ  위의 화학식 Ⅰ에서 R1은 페닐기, 치환 페닐기, 방향족 복소환기 또는 치환 방향족 복소환기이며, R2는 (C1-C8) 알킬기, 치환 (C1-C8) 알킬기, 페닐기, 치환 페닐기, 아르알킬기, 치환 아르알킬기, 방향족 복소환기, 치환 방향족 복소환기, 아미노기, 동일하거나 상이할 수 있으며 1 또는 2개의 (C1-C8) 알킬기로 치환된 아미노기, 4 내지 10원 환의 환상 아미노기, 시아노기, 카복실기, (C1-C8) 알콕시카보닐기, 카바모일기, 티오카바모일기, 아미노카보닐기, 동일하거나 상이할 수 있으며 1 또는 2개의 (C1-C8) 알킬기 또는 치환 (C1-C8) 알킬기로 치환된 아미노카보닐기, 4 내지 10원 환의 환상 아미노카보닐기, 페닐아미노카보닐기, 치환 페닐아미노카보닐기, 방향족 복소환 아미노카보닐기 또는 치환 방향족 복소환 아미노카보닐기이며, R3은 수소원자, (C1-C8) 알킬기, 치환 (C1-C8) 알킬기, 페닐기, 치환 페닐기, 방향족 복소환기 또는 치환 방향족 복소환기이며, R4는 시아노기, [여기서, R5는 수소원자, (C1-C8) 알킬기, 치환 (C1-C8) 알킬기, (C1-C8) 알콕시기, 하이드록실기, 아미노기, 동일하거나 상이할 수 있으며 1 또는 2개의 (C1-C8) 알킬기로 치환된 아미노기, 4 내지 10원 환의 환상 아미노기, 페닐기, 치환 페닐기, 방향족 복소환기 또는 치환 방향족 복소환기이거나, R5는 R3과 함께 (CR72)m(여기서, R7은 동일하거나 상이할 수 있으며 수소원자, (C1-C8) 알킬기, 치환 (C1-C8) 알킬기, 페닐기, 치환 페닐기, 방향족 복소환기 또는 치환 방향족 복소환기이며, m은 2 내지 7의 정수이다)로 되어 환화할 수 있으며, Y는 NH, O 또는 S이다], [여기서, R6은 수소원자, (C1-C8) 알킬기, 치환 (C1-C8 ) 알킬기, 페닐기, 치환 페닐기, 방향족 복소환기 또는 치환 방향족 복소환기이거나, R6은 R3과 함께 (CR72)m(여기서, R7 및 m은 위에서 정의한 바와 동일하다)로 되어 환화할 수 있으며, R8은 수소원자 또는 (C1-C8) 알킬카보닐기이다] 또는 [여기서, R6은 위에서 정의한 바와 동일하며, R9 및 R10은 동일하거나 상이할 수 있으며 (C1 -C8) 알킬기, 치환 (C1-C8) 알킬기이거나, R9 및 R10은 함께 (C2 -C4) 알킬렌쇄를 형성하고 이들이 결합되어 있는 원자와 함께 환화할 수 있다]이며, X는 단일결합, O 또는 S(O)n(여기서, n은 0, 1 또는 2의 정수이다)이다. 