Amidine compounds

An amidine compound of the formula [I]

• 414
• wherein
• R is a group of the formula
• 415
• wherein
• R4 is hydrogen atom, hydroxy group, lower alkyl group, lower alkoxy group or halogen atom,
• R5 is hydrogen atom, cyano group, carboxy group or lower alkoxycarbonyl group,
• R6 is hydrogen atom, cycloalkyl group, hydroxy group, carboxy group, lower alkoxycarbonyl group, aralkyloxycarbonyl group
• wherein said aralkyloxycarbonyl group is optionally substituted by halogen atom, nitro group, alkyl group, alkoxy group or trifluoromethyl group,
• nitro group, amino group, lower alkylamino group, di(lower)alkylamino group, aryl group, heteroaryl group
• wherein said aryl group or heteroaryl group is optionally substituted by 1 to 3 substituents selected from lower alkyl group, hydroxy group, lower alkoxy group, carboxy group, lower alkoxycarbonyl group, aralkyloxycarbonyl group, nitro group, amino group, acylamino group, amidino group and hydroxyamidino group,
• 5- to 7-membered saturated heterocycle having at least one nitrogen atom,
• wherein said saturated heterocycle is optionally substituted by lower alkyl group, acyl group, di(lower)alkylamino(lower)alkanoyl group or imidoyl group,
• or
• 416
• wherein Ak is lower alkyl group and Hal is halogen atom,
• X2 is oxygen atom, sulfur atom, —SO2—, —SO2NH— or a single bond,
• X3 is —(CH2)m— wherein m is 0 or an integer of 1 to 3,
• X4 is —CO—, —C(═NH)—, —SO2—, —CONH—, —CSNH—, —SO2NH—, —(CH2)rCONH—, —(CH2)rCH(OH)—,
• 417
• wherein r is 0 or an integer of 1 to 3,
• or a single bond,
• X5 is alkylene group having 1 to 6 carbon atoms, alkenylene group having 2 to 6 carbon atoms, or a single bond,
• R7 is hydrogen atom, lower alkyl group or
• 418
• wherein R9 is oxygen atom, sulfur atom, NH, NR11
• wherein R11 is lower alkyl group, aralkyl group
• wherein said aralkyl group is optionally substituted by 1 to 3 substituents selected from halogen atom, lower alkyl group, hydroxy group, lower alkoxy group, halo alkyl group, cyano group, nitro group, amino group and acyloxy group,
• or hydroxy group,
• and R10 is lower alkyl group, lower alkoxy group, amino group, lower alkylamino group or di(lower)alkylamino group,
• R8 is hydrogen atom, lower alkyl group, cycloalkyl group
• wherein said cycloalkyl group is optionally substituted by lower alkyl group or carboxy group,
• carboxy group, lower alkoxycarbonyl group, aryl group, heteroaryl group
• wherein said aryl group or heteroaryl group is optionally substituted by 1 to 3 substituents selected from halogen atom, lower alkyl group
• wherein said lower alkyl group is optionally substituted by halogen atom, hydroxy group, lower alkoxy group, carboxy group and lower alkoxycarbonyl group,
• aralkyl group
• wherein said aralkyl group is optionally substituted by 1 to 3 substituents selected from halogen atom, lower alkyl group, hydroxy group, lower alkoxy group, haloalkyl group, cyano group, nitro group, amino group and acyloxy group,
• or 5 to 7-membered saturated heterocycle having at least one nitrogen atom,
• Y1 is oxygen atom, —NH—, —CONH—, —NR12—
• wherein R12 is lower alkyl group or —Y6—R13
• wherein R13 is hydrogen atom, lower alkyl group or aryl group
• wherein said lower alkyl group or aryl group is optionally substituted by carboxy group, lower alkoxycarbonyl group or aralkyloxycarbonyl group,
• Y6 is —CO—, CO2—, —COCO2—, —SO2—, —SO2(CH2)r— or —(CH2)r—
• wherein r is 0 or an integer of 1 to 3,
• or a single bond,
• Y2 is oxygen atom, sulfur atom or a single bond,
• Y3 is
• 419
• wherein s and t are the same or different and each is an integer of 1 to 3,
• or a single bond,
• Y4 is oxygen atom, —CO—, —CO2—, —SO2—, —CONH—, —CH═CH— or a single bond,
• Y5 is —(CH2)p—, —(CH2)p′—CHAk—(CH2)p″—, —(CH2)p′—CAk Ak′—(CH2)p″—,
• 420
• wherein Ak, Ak′ are the same or different and each is lower alkyl group, p is 0 or an integer of 1 to 3, p′ and p″ are the same or different and each is 0 or an integer of 1 or 2,
• or a single bond,
• ring A is
• 421
• wherein R14 is carboxy group, lower alkoxycarbonyl group or aralkyloxycarbonyl group
• wherein said aralkyloxycarbonyl group is optionally substituted by halogen atom, nitro group, alkyl group, alkoxy group or trifluoromethyl group,
• j is 1 or 2,
• k is 0 or 1, and
• m and n are the same or different and each is 0 or an integer of 1 to 3;
• and
• R1, R2 and R3 are the same or different and each is hydrogen atom, hydroxy group, lower alkyl group or aryl group,
• or a salt thereof or a prodrug thereof.