Abstract: A cyclic amidine derivative represented by the formula: [wherein R1, R2 and R3 represent hydrogen, C1-6 alkyl, aryl-C1-6 alkyl, etc.; R4, R5 and R7 represent hydrogen, C1-6 alkyl, etc.; Z represents 0 or 1; R6 represents hydrogen, C1-6 alkyl, C1-6 alkyloxycarbonyl, etc.; n represents 1 or 2; Y1 represents a single bond, —CH2—, etc.; Y2 represents a single bond, —CO—, etc.; Ar represents hydrogen, a group represented by the formula: [wherein R10-R14 represent hydrogen, C1-6 alkyl, hydroxyl, C1-6 alkoxy, etc., and R11 and R12 or R12 and R13 may bond together to form a 5- to 8-membered heterocycle], etc.] or a salt thereof.

Abstract: A 2-iminoimidazole derivative represented by the formula: {wherein R1, R2 and R3 represent hydrogen, optionally substituted C1-6 alkyl, etc.; R6 represents hydrogen, C1-6 alkyl, C1-6 alkyloxycarbonyl, etc.; Y1 represents a single bond, —CH2—, etc.; Y2 represents a single bond, —CO—, etc.; and Ar represents hydrogen, a group represented by the formula: [wherein R10–R14 represent hydrogen, C1-6 alkyl, hydroxyl, C1-6 alkoxy, etc., and R11 and R12 or R12 and R13 may bond together to form a 5- to 8-membered heterocycle], etc.}or salt thereof.

Abstract: A 2-iminopyrrolidine derivative represented by the formula: {wherein ring B represents a benzene ring, pyridine ring, etc.; R101-R103 represent hydrogen, halogen, C1-6 alkyl, etc.; R5 represents hydrogen, C1-6 alkyl, C1-6 alkoxy-C1-6 alkyl, etc.; R6 represents hydrogen, C1-6 alkyl, C1-6 alkyloxycarbonyl, etc.; Y1 represents a single bond, —CH2—, etc.; Y2 represents a single bond, —CO—, etc.; and Ar represents hydrogen, a group represented by the formula: [wherein R10-R14 represent hydrogen, C1-6 alkyl, hydroxyl, C1-6 alkoxy, etc.; and R11 and R12 or R12 and R13 may bond together to form a 5- to 8-membered heterocyclic ring], etc.}, or a salt thereof.

Abstract: A 2-iminoimidazole derivative represented by the formula: {wherein R1, R2 and R3 represent hydrogen, optionally substituted C1-6 alkyl, etc.; R6 represents hydrogen, C1-6 alkyl, C1-6 alkyloxycarbonyl, etc.; Y1 represents a single bond, —CH2—, etc.; Y2 represents a single bond, —CO—, etc.; and Ar represents hydrogen, a group represented by the formula: [wherein R10-R14 represent hydrogen, C1-6 alkyl, hydroxyl, C1-6 alkoxy, etc., and R11 and R12 or R12 and R13 may bond together to form a 5- to 8-membered heterocycle], etc.} or salt thereof.

Abstract: A 2-iminopyrrolidine derivative represented by the formula: {wherein ring B represents a benzene ring, pyridine ring, etc.; R101-R103 represent hydrogen, halogen, C1-6 alkyl, etc.; R5 represents hydrogen, C1-6 alkyl, C1-6 alkoxy-C1-6 alkyl, etc.; R6 represents hydrogen, C1-6 alkyl, C1-6 alkyloxycarbonyl, etc.; Y1 represents a single bond, —CH2—, etc.; Y2 represents a single bond, —CO—, etc.; and Ar represents hydrogen, a group represented by the formula: [wherein R10—R14 represent hydrogen, C1-6 alkyl, hydroxyl, C1-6 alkoxy, etc.; and R11 and R12 or R12 and R13 may bond together to form a 5- to 8-membered heterocyclic ring], etc.}, or a salt thereof.

Abstract: A cyclic amidine derivative represented by the formula: 1

Abstract: A 2-iminoimidazole derivative represented by the formula: 1

Abstract: The biphenylmethane derivative having the formula (I) is useful to prevent and treat hypertension and cardiac failure. ##STR1## in which R1 is hydrogen, an alkyl, a cycloalkyl, a halogenated alkyl, --S--R7, --SO2--R7, --C.tbd.C--R7 or --(CH2)p--OR7, R7 being hydrogen, an alkyl, a cycloalkyl or a halogenated alkyl, p being zero or 1, --A1=A2--A3=A4-- is --CH=CH--CH=CH--, --N=CH--CH=CH--, --CH=N--CH=CH--, --CH=CH--N=CH--, --CH=CH--CH=N-- or --CH=N--CH=N--, R2 and R3 are each hydrogen, a halogen, a lower alkyl, a lower alkoxy, a carbamoyl or cyano, R4 is hydrogen or a lower alkyl, R5 is 1H-tetrazol-5-yl, carboxyl (--COOH) or a carboxylic ester and R6 is hydrogen, a halogen, hydroxyl or a lower alkoxy, or a pharmacologically acceptable salt thereof.

Abstract: The biphenylmethane derivative having the formula (I) is useful to prevent and treat hypertension and cardiac failure. ##STR1## in which R1 is hydrogen, an alkyl, a cycloalkyl, a halogenated alkyl, --S--R7, --SO2--R7, --C.tbd.C--R7 or --(CH2)p--OR7, R7 being hydrogen, an alkyl, a cycloalkyl or a halogenated alkyl, p being zero or 1, --A1.dbd.A2--A3.dbd.A4-- is --CH.dbd.CH--CH.dbd.CH--, --N.dbd.CH--CH.dbd.CH--, --CH.dbd.N--CH.dbd.CH--, --CH.dbd.CH--N.dbd.CH--, --CH.dbd.CH--CH.dbd.N-- or --CH.dbd.N--CH.dbd.N--, R2 and R3 are each hydrogen, a halogen, a lower alkyl, a lower alkoxy, a carbamoyl or cyano, R4 is hydrogen or a lower alkyl, R5 is 1H-tetrazol-5-yl, carboxyl (--COOH) or a carboxylic ester and R6 is hydrogen, a halogen, hydroxyl or a lower alkoxy, or a pharmacologically acceptable salt thereof.

Abstract: The biphenylmethane derivative having the formula (I) is useful to prevent and treat hypertension and cardiac failure. ##STR1## in which R1 is hydrogen, an alkyl, a cycloalkyl, a halogenated alkyl, --S--R7, --SO2--R7, --C.tbd.C--R7 or --(CH2)--OR7, R7 being hydrogen, an alkyl, a cycloalkyl or a halogenated alkyl, p being zero or 1, --A1.dbd.A2--A3.dbd.A4-- is CH.dbd.CH--CH.dbd.CH--, --N.dbd.CH--CH.dbd.CH--, --CH.dbd.N--CH.dbd.CH--, --CH.dbd.CH--N.dbd.CH--, --CH.dbd.CH--CH.dbd.N-- or --CH.dbd.N--CH.dbd.N--, R2 and R3 are each hydrogen, a halogen, a lower alkyl, a lower alkoxy, a carbamoyl or cyano, R4 is hydrogen or a lower alkyl, R5 is 1H-tetrazol-5-yl, carboxyl (--COOH) or a carboxylic ester and R6 is hydrogen, a halogen, hydroxyl or a lower alkoxy, or a pharmacologically acceptable salt thereof.