Quinazoline derivatives and medicaments

1. A quinazoline derivative represented by general formula (1b) or a salt thereof:

wherein R 1 represents a hydrogen atom or alkyl;

the ring Q represents a cyclohexylene group or a phenylene group;

A 1 and A 2 are the same or different and each represents a single bond or an alkylene group;

R 2 represents a hydrogen atom or alkyl;

A 3 represents A 31 -A 32 -A 33 ,

A 31 and A 33 are the same or different and each represents a single bond, or a divalent saturated or unsaturated aliphatic hydrocarbon group having 1to 6 carbon atoms which may have the same or different 1 or 2 substituents at a substitutable position; wherein the substituents are selected from alkyl, alkoxy, phenyl, alkoxyalkyl, alkoxycarbonyl, dialkylamino, and oxo; or when one carbon atom has two branched chains, the branched chains may be taken together with the carbon atom to form divalent cycloalkyl;

A 32 represents a single bond, an oxygen atom, a sulfur atom, or —N(R 32 )—, wherein R 32 represents a hydrogen atom or alkyl;

R 3 represents an optionally substituted non-cyclic aliphatic hydrocarbon group having 1 to 8 carbon atoms, wherein the substituents are selected from alkyl, hydroxy, alkoxy, phenyl, alkoxy-substituted phenyl, halogen-substituted phenyl, hydroxy-substituted phenyl, phenoxy, alkylthio, carboxy, alkoxycarbonyl, acyl, amino, monoalkylamino, dialkylamino, acyl amino, alkylsulfonyl, alkylsulfonylamino, phenylsulfonyl, oxo, cyano, trifluoromethyl, benzoyl, benzyloxycarbonyl, benzylthio and imidazol-4-yl; an optionally substituted cyclic aliphatic hydrocarbon group having 3 to 10 carbon atoms which is mono- to tricyclic, wherein the substituents are selected from alkyl, alkynyl, alkoxy, alkoxycarbonyl, carbamoyl, aryl, alkoxyalkyl, acyl and oxo, and wherein the cyclic aliphatic hydrocarbon group may be fused with 1 or 2 benzene rings; or an optionally substituted aromatic hydrocarbon group having 6 to 12 carbon atoms which is mono- or dicyclic, wherein the substituents are selected from alkyl, arylalkyl, arylalkenyl, alkenyl, cinnamyl, alkoxy, phenyl, phenoxy, acyl, acylamino, alkoxycarbonyl, amino, aminoalkyl, monoalkylamino, dialkylamino, dialkylaminosulfonyl, alkylsulfonyl, alkylsulfonylamino, phenylsulfonyl, oxo, cyano, nitro, aminosulfonyl, halogen, trifluoromethyl, trifluoromethoxy, alkylthio, 1H-pyrrol-1-yl, 5-oxo-4,5-dihydro-1H-pyrazol-1-yl and aminosulfonyl; or the —N(R 2 )— may be taken together with -A 3 -R 3 to form a mono- to tricyclic amino group; wherein the mono- to tricyclic amino group may have the same or different 1 to 3 substituents selected from the group consisting of alkyl, alkoxy, alkoxyalkyl, acyl, acylamino, alkoxycarbonyl, carbamoyl, monoalkylcarbamoyl, dialkylcarbamoyl, aryl optionally substituted with alkoxy, arylalkyl, arylalkenyl, piperidino, pyridyl, pyrimidinyl, pyrazinyl, and 1,3-benzodioxol-5-ylmethyl;

provided that R 3 is not an optionally substituted phenyl group; and

R 4 and R 5 are the same or different and each represents a hydrogen atom, alkyl, alkoxy or halogen.

2. The quinazoline derivative according to claim 1 or a salt thereof, wherein R 1 is a hydrogen atom.

3. The quinazoline derivative according to claim 1 or a salt thereof, wherein the ring Q is a cyclohexylene group.

4. The quinazoline derivative according to claim 1 , or a salt thereof, wherein A 1 and A 2 represent a single bond.

5. The quinazoline derivative according to claim 1 or a salt thereof, wherein A 31 , A 32 and A 33 represent a single bond.

6. The quinazoline derivative according to claim 1 or a salt thereof, wherein R 2 is a hydrogen atom.

7. The quinazoline derivative according to claim 1 or a salt thereof, wherein R 3 is an optionally substituted non-cyclic aliphatic hydrocarbon group having 1 to 8 carbon atoms, or an optionally substituted cyclic aliphatic hydrocarbon group having 3 to 10 carbon atoms which is mono- to tricyclic.

8. The quinazoline derivative according to claim 1 or a salt thereof, wherein R 4 and R 5 are the same or different and each represents a hydrogen atom or alkyl.

9. The quinazoline derivative according to claim 1 or a salt thereof, wherein R 1 is a hydrogen atom, the ring Q is a cyclohexylene group, A 1 and A 2 represent a single bond, A 31 , A 32 and A 33 represent a single bond, R 2 is a hydrogen atom, R 3 is an optionally substituted non-cyclic aliphatic hydrocarbon group having 1 to 8 carbon atoms or an optionally substituted cyclic aliphatic hydrocarbon group having 3 to 10 carbon atoms which is mono- to tricyclic, and R 4 and R 5 are the same or different and each represents a hydrogen atom or alkyl.

10. A quinazoline derivative or a salt thereof, wherein the quinazoline derivative is a compound selected from the group consisting of

4-[((1S,2R)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-6-methyl-N-neopentylquinazoline-2-carboxamide,

4-[((1S,2R)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-N-(3,3-dimethylbutyl)-6-methylquinazoline-2-carboxamide,

4-[((1S,2R)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-N-cycloheptyl-6-methylquinazoline-2-carboxamide,

4-[((1S,2R)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-N-(2ethylbutyl)-6-methylquinazoline-2-carboxamide,

4-[((1S,2R)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-6-methyl-N-n-propylquinazoline-2-carboxamide, and

4-[((1S,2R)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-N-isobutyl-6-methylquinazoline-2-carboxamide.

11. An antipruritic composition comprising the quinazoline derivative represented by the general formula (1b) of claim 1 or a salt thereof as an active ingredient, and a pharmaceutically acceptable carrier.

12. A method for treating itching, which comprises administering to a subject in need thereof an effective amount of the quinazoline derivative represented by the general formula (1b) of claim 1 or a salt thereof.

13. The quinazoline derivative according to claim 1 , wherein the pyridyl substituent is selected from pyridin-2-yl and pyridin-4-yl.

14. The quinazoline derivative according to claim 1 , wherein the pyrimidinyl substituent is pyrimidin-2-yl.

15. The quinazoline derivative according to claim 1 , wherein the pyrazinyl substituent is pyrazin-2-yl.

16. A quinazoline derivative or a salt thereof, which is selected from the group consisting of:

4-[((1S,2R)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-N-(4-methoxyphenyl)-6-methylquinazoline-2-carboxamide dihydrochloride;

4-[((1S,2R)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-N-(4-bromophenyl)-6-methylquinazoline-2-carboxamide dihydrochloride;

4-[((1S,2R)-2-[amino(imino)methyl]amino}cyclohexyl)amino]-6-methyl-N-{4-[(methylsulfonyl)aminophenyl]quinazoline-2-carboxamide dihydrochloride;

4-[((1S,2R)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-N-(4-methoxyphenyl)-N,6-dimethylquinazoline-2-carboxamide dihydrochloride;

4-[((1S,2R)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-N-1-benzothiophen-2-yl-6-methylquinazoline-2-carboxamide dihydrochloride;

4-[((1S,2R)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-6-methyl-N-thiophen-3-ylquinazoline-2-carboxamide dihydrochloride;

4-((1S,2R)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-6-methyl-N-pyridin-2-ylquinazoline-2-carboxamide trihydrochloride;

4-[((1S,2R)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-6-methyl-N-quinolin-3-ylquinazoline-2-carboxamide trihydrochloride;

4-[((1S,2R)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-N-(4-chlorophenyl)-6-methylquinazoline-2-carboxamide dihydrochloride;

4-[((1S,2R)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-6-chloro-N-(4-methoxyphenyl)quinazoline-2-carboxamide dihydrochloride;

4-[((1S,2R)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-6-methoxy-N-(4-methoxyphenyl)quinazoline-2-carboxamide dihydrochloride;

4-[((1S,2R)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-6-methyl-N-(1-methyl-1H-benzimidazol-2-yl)quinazoline-2-carboxamide trihydrochloride;

4-[((1S,2R)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-6-methyl-N-thiophen-2-ylquinazoline-2-carboxamide dihydrochloride; 4-[((1S,2R)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-N-(4-methoxyphenyl)quinazoline-2-carboxamide dihydrochloride;

4-[((1S,2R)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-6-methyl-N-[4-(trifluoromethoxy)phenyl]quinazoline-2-carboxamide dihydrochloride;

4-[((1S,2R)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-N-(3,5-dimethylphenyl)-6-methylquinazoline-2-carboxamide dihydrochloride;

4-[((1S,2R)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-N-(2,6-dimethylphenyl)-6-methylquinazoline-2-carboxamide dihydrochloride;

4-[((1S,2R)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-N-(3,4-dimethylphenyl)-6-methylquinazoline-2-carboxamide dihydrochloride;

4-[((1S,2R)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-6-methyl-N-(2-oxo-2H-chromen-6-yl)quinazoline-2-carboxamide dihydrochloride;

4-[((1S,2R)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-N-(3-chloro-4-methoxyphenyl)-6-methylquinazoline-2-carboxamide dihydrochloride;

4-[((1S,2R)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-6-methyl-N-(3-oxo-3,4-dihydro-2H-1,4-benzoxazin-6-yl)quinazoline-2-carboxamide dihydrochloride;

4-[((1S,2R)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-N-(6-chloropyridin-3-yl)-6-methylquinazoline-2-carboxamide trihydrochloride;

4-[((1S,2R)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-N-(3,3-dimethylbutyl)-6-methylquinazoline-2-carboxamide trihydrochloride;

4-[((1S,2R)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-6-methyl-N-{4-[(E)-2-phenylvinyl]phenyl}quinazoline-2-carboxamide dihydrochloride;

4-[((1S,2R)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-6,7-dimethoxy-N-(4-methoxyphenyl)quinazoline-2-carboxamide dihydrochloride;

4-[(2-{[amino(imino)methyl]amino}cyclohexyl)amino]-6-methyl-N-quinolin-6-ylquinazoline-2-carboxamide tris(trifluoroacetate);

4-[(2-{[amino(imino)methyl]amino}cyclohexyl)amino]-N-(4-chlorophenyl)-6-methylquinazoline-2-carboxamide bis(trifluoroacetate);

4(2-{[amino(imino)methyl]amino}cyclohexyl)amino]-6-methyl-N-(2-thiophen-2-ylethyl)quinazoline-2-carboxamide bis(trifluoroacetate);

4-[(2-{[amino(imino)methyl]amino}cyclohexyl)amino]-6-methyl-N-[3-(trifluoromethyl)benzyl]quinazoline-2-carboxamide bis(trifluoroacetate);

4-[((1RS,2SR)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-N,6-dimethyl-N-(1-methylpiperidin-4-yl)quinazoline-2-carboxamide tris(trifluoroacetate);

4-[((1RS,2SR)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-N-2,3-dihydro-1,4-benzodioxan-6-yl-6-methylquinazoline-2-carboxamide bis(trifluoroacetate);

4-[((1RS,2SR)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-N-(1-benzylpiperidin-4-yl)-6-methylquinazoline-2-carboxamide tris(trifluoroacetate);

4-[((1RS,2SR)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-N-1,3-benzothiazol-2-yl-6-methylquinazoline-2-carboxamide bis(trifluoroacetate);

4-[((1RS,2SR)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-N-1-azabicyclo[2.2.2]oct-3-yl-6-methylquinazoline-2-carboxamide tris(trifluoroacetate);

N-((1RS,2SR)-2-{[6-methyl-2-(1,3-thiazolidin-3-ylcarbonyl)quinazolin-4-yl]amino}cyclohexyl)guanidine bis(trifluoroacetate);

4-[((1RS,2SR)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-6-methyl-N-(3-(2-methylpiperidin-1-yl)propyl)quinazoline-2-carboxamide tris(trifluoroacetate);

4-[((1RS,2SR)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-6-methyl-N-(2-(pyridin-2-yl)ethyl)quinazoline-2-carboxamide tris(trifluoroacetate);

4-[((1RS,2SR)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-6-methyl-N-{3-[methyl(phenyl)amino]propyl}quinazoline-2-carboxamide tris(trifluoroacetate);

4-[((1RS,2SR)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-N-(3-methoxyphenyl)-6-methylquinazoline-2-carboxamide bis(trifluoroacetate);

4-[((1RS,2SR)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-6-methyl-N-(pyridin-3-yl)quinazoline-2-carboxamide tris(trifluoroacetate);

4-[((1RS,2SR)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-6-methyl-N-(2-(morpholin-4-yl)ethyl)quinazoline-2-carboxamide tris(trifluoroacetate);

4-[((1RS,2SR)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-N-2,3-dihydro-1H-inden-5-yl-6-methylquinazoline-2-carboxamide bis(trifluoroacetate);

4-[((1RS,2SR)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-6-methyl-N-(3-phenoxyphenyl)quinazoline-2-carboxamide bis(trifluoroacetate);

4-[((1RS,2SR)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-6-methyl-N-(tetrahydrofuran-2-ylmethyl)quinazoline-2-carboxamide bis(trifluoroacetate);

4-[((1RS,2SR)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-N-(6-ethoxy-1,3-benzothiazol-2-yl)-6-methylquinazoline-2-carboxamide bis(trifluoroacetate);

4-[((1RS,2SR)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-6-methyl-N-(pyridin-2-ylmethyl)quinazoline-2-carboxamide tris(trifluoroacetate);

4-[((1RS,2SR)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-6-methyl-N-(pyridin-4-ylmethyl)quinazoline-2-carboxamide tris(trifluoroacetate);

4-[((1RS,2SR)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-6-methyl-N-(pyridin-3-ylmethyl)quinazoline-2-carboxamide tris(trifluoroacetate);

4-[((1RS,2SR)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-N-(1,3-benzodioxol-5-ylmethyl)-6-methylquinazoline-2-carboxamide bis(trifluoroacetate);

4-[((1RS,2SR)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-N-(4-benzylphenyl)-6-methylquinazoline-2-carboxamide bis(trifluoroacetate);

4-[((1RS,2SR)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-N-[4-(dimethylamino)benzyl]-6-methylquinazoline-2-carboxamide tris(trifluoroacetate);

4-[((1RS,2SR)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-N-(2-furylmethyl)-6-methylquinazoline-2-carboxamide bis(trifluoroacetate);

4-[((1RS,2SR)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-N-[(3R)-1-benzylpyrrolidin-3-yl]-6-methylquinazoline-2-carboxamide tris(trifluoroacetate);

4[((1RS,2SR)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-N-[2-(1-benzylpyrrolidin-3-yl)ethyl]-6-methylquinazoline-2-carboxamide tris(trifluoroacetate);

4-[((1RS,2SR)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-N-[2-(1H-indol-3-yl)ethyl]-6-methylquinazoline-2-carboxamide bis(trifluoroacetate);

4-[((1RS,2SR)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-N-[(3S)-1-benzylpyrrolidin-3-yl]-6-methylquinazoline-2-carboxamide tris(trifluoroacetate);

4-[((1RS,2SR)-2-{[(amino(imino)methyl]amino}cyclohexyl)amino]-N-(1-benzylpyrrolidin-3-yl)-N,6-dimethylquinazoline-2-carboxamide tris(trifluoroacetate);

4-[((1RS,2SR)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-N-{2-[(2-furylmethyl)thio]ethyl}-6-methylquinazoline-2-carboxamide bis(trifluoroacetate);

4-[((1RS,2SR)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-6-methyl-N-[(5-methylpyrazin-2-yl)methyl]quinazoline-2-carboxamide bis(trifluoroacetate);

4-[((1RS,2SR)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-6-methyl-N-(tetrahydrofuran-2-ylmethyl)quinazoline-2-carboxamide bis(trifluoroacetate);

4-[((1RS,2SR)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-6-methyl-N-[4-(trifluoromethyl)benzyl]quinazoline-2-carboxamide bis(trifluoroacetate);

4-[((1RS,2SR)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-6-methyl-N-[4-(trifluoromethoxy)benzyl]quinazoline-2-carboxamide bis(trifluoroacetate);

4[((1RS,2SR)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-N-(6-chloropyridin-3-yl)-6-methylquinazoline-2-carboxamide tris(trifluoroacetate);

4-[((1RS,2SR)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-N-[4-(aminomethyl)benzyl]-6-methylquinazoline-2-carboxamide tris(trifluoroacetate);

4-[((1RS,2SR)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-6-methyl-N-(2-(pyridin-2-yl)ethyl)quinazoline-2-carboxamide tris(trifluoroacetate);

4-[((1RS,2SR)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-N-{[(2S)-1-ethylpyrrolidin-2-yl]methyl}-6-methylquinazoline-2-carboxamide tris(trifluoroacetate);

4-[((1RS,2SR)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-N-[3-fluoro-5-(trifluoromethyl)benzyl]-6-methylquinazoline-2-carboxamide bis(trifluoroacetate);

4-[((1RS,2SR)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-N-{2-[4-(aminosulfonyl)phenyl]ethyl}-6-methylquinazoline-2-carboxamide bis(trifluoroacetate);

4-[((1RS,2SR)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-N-[2-(1,3-benzodioxol-5-yl)ethyl]-6-methylquinazoline-2-carboxamide bis(trifluoroacetate);

4-[((1RS,2SR)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-N-{2-[benzyl(methyl)amino]ethyl}-N,6-dimethylquinazoline-2-carboxamide tris(trifluoroacetate);

4-[((1RS,2SR)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-6-methyl-N-(thiophen-2-ylmethyl)quinazoline-2-carboxamide bis(trifluoroacetate);

4-[((1RS,2SR)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-N-[5-(ethylthio)-1,3,4-thiadiazol-2-yl]-6-methylquinazoline-2-carboxamide bis(trifluoroacetate);

4-[((1RS,2SR)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-6-methyl-N-[2-(2-phenoxyphenyl)ethyl]quinazoline-2-carboxamide bis(trifluoroacetate);

4-[((1RS,2SR)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-N-[2-(1,1′-biphenyl-4-yl) ethyl]-6-methylquinazoline-2-carboxamide bis(trifluoroacetate);

4-[((1RS,2SR)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-6-methyl-N-(5-nitro-1,3-thiazol-2-yl)quinazoline-2-carboxamide bis(trifluoroacetate);

4-[((1RS,2SR)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-N-[3,5-bis(trifluoromethyl)benzyl]-6-methylquinazoline-2-carboxamide bis(trifluoroacetate);

4-[((1RS,2SR)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-6-methyl-N-[2-(2-methylphenyl)ethyl]quinazoline-2-carboxamide bis(trifluoroacetate);

4-[((1RS,2SR)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-6-methyl-N-(3-(morpholin-4-yl)propyl)quinazoline-2-carboxamide bis(trifluoroacetate);

4-[((1RS,2SR)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-N-(3,5-di-tert-butylphenyl)-6-methylquinazoline-2-carboxamide bis(trifluoroacetate);

4-[((1RS,2SR)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-N-(6-methoxypyridin-3-yl)-6-methylquinazoline-2-carboxamide tris(trifluoroacetate);

4-[((1RS,2SR)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-6-methyl-N-[3-(4-methylpiperazin-1-yl)propyl]quinazoline-2-carboxamide bis(trifluoroacetate);

4-[((1RS,2SR)-2-{[(amino(imino)methyl]amino}cyclohexyl)amino]-N-(3,4-dimethoxyphenyl)-6-methylquinazoline-2-carboxamide bis(trifluoroacetate);

4-[((1S,2R)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-N-(4-methoxyphenyl)-8-methylquinazoline-2-carboxamide dihydrochloride;

4-[((1S,2R)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-6-methyl-N-(2-oxo-2,3-dihydro-1H-benzimidazol-5-yl)quinazoline-2-carboxamide dihydrochloride;

4-[((1S,2R)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-6-methyl-N-(2-(pyridin-2-yl)ethyl)quinazoline-2-carboxamide trihydrochloride;

4-[((1S,2R)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-6-methyl-N-(2-(morpholin-4-yl)ethyl)quinazoline-2-carboxamide trihydrochloride;

4-[((1S,2R)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-6-methyl-N-(5-methyl-1,3-thiazol-2-yl)quinazoline-2-carboxamide trihydrochloride;

4-[((1S,2R)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-6-methyl-N-quinolin-6-ylquinazoline-2-carboxamide trihydrochloride;

4-[((1S,2R)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-N-(1H-benzimidazol-2-ylmethyl)-6-methylquinazoline-2-carboxamide trihydrochloride;

4-[((1S,2R)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-6-methyl-N-[(1-(pyridin-2-yl)pyrrolidin-2-yl)methyl]quinazoline-2-carboxamide trihydrochloride;

4-[((1S,2R)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-6-methyl-N-[2-(4-methyl-1,3-thiazol-5-yl)ethyl]quinazoline-2-carboxamide trihydrochloride;

4-[((S,2R)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-N-[2-(3,5-dimethylisoxazol-4-yl)ethyl]-6-methylquinazoline-2-carboxamide;

4-[((1S,2R)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-6-methyl-N-[4-(trifluoromethoxy)benzyl]quinazoline-2-carboxamide dihydrochloride;

4-[((1S,2R)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-6-methyl-N-[2-(3-thienyl)ethyl]quinazoline-2-carboxamide dihydrochloride;

4-[((1S,2R)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-6-methyl-N-(2-(pyridin-4-yl)ethyl)quinazoline-2-carboxamide trihydrochloride;

4-[((1S,2R)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-6-methyl-N-(3-pyridin-3-ylpropyl)quinazoline-2-carboxamide trihydrochloride;

4-[((1S,2R)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-6-methyl-N-[2-(trifluoromethyl)benzyl]quinazoline-2-carboxamide dihydrochloride;

4-[((1S,2R)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-N-[3,5-bis(trifluoromethyl)benzyl]-6-methylquinazoline-2-carboxamide dihydrochloride;

4-[((1S,2R)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]6-methyl-N-[3-(trifluoromethyl)benzyl]quinazoline-2-carboxamide dihydrochloride;

4-[((1RS,2SR)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-N-(2-[ethyl(3-methylphenyl)amino]ethyl}-6-methylquinazoline-2-carboxamide bis(trifluoroacetate);

4-[((1RS,2SR)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-6-methyl-N-(2-(pyridin-4-yl)ethyl)quinazoline-2-carboxamide tris(trifluoroacetate);

4-[((1RS,2SR)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-N-(2-furylmethyl)-6-methylquinazoline-2-carboxamide bis(trifluoroacetate);

4-[((1RS,2SR)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-N-(1H-benzimidazol-2-ylmethyl)-6-methylquinazoline-2-carboxamide tris(trifluoroacetate);

4-[((1RS,2SR)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-6-methyl-N-(2-(pyridin-3-yl)ethyl)quinazoline-2-carboxamide tris(trifluoroacetate);

4-[((1RS,2SR)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-6-methyl-N-[(5-methylpyrazin-2-yl)methyl]quinazoline-2-carboxamide tris(trifluoroacetate);

4-[((1RS,2SR)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-6-methyl-N-(2-oxotetrahydrofuran-3-yl)quinazoline-2-carboxamide bis(trifluoroacetate);

4-[((1RS,2SR)-2-{[amino(imino)methyl]amino}cyclohexyl)amino]-6-methyl-N-(2-(pyrrolidin-1-yl)ethyl)quinazoline-2-carboxamide tris(trifluoroacetate); and

4-[(2-{[amino(imino)methyl]amino}phenyl)amino)-N-(4-methoxyphenyl)-6-methylquinazoline-2-carboxamide dihydrochloride.

17. A method of treating a disease associated with itching, wherein the disease is selected from pruritic dermatitis associated with skin lesion and pruritus cutaneous, comprising administering to a subject in need thereof an effective amount of the quinazoline derivative represented by the general formula (1b) of claim 1 or a salt thereof.

18. The method of claim 17 , wherein the pruritic dermatitis associated with skin lesion is selected from atopic dermatitis, urticaria, psoriasis, xeroderma, and trichophytia.