R¹ denotes a C_1-3-alkyl group substituted by a group R_a, wherein

R_a denotes a 1,4-dihydro-quinazolinyl or 3,4-dihydro-quinazolinyl group wherein in each case in the benzo moiety

one to three methyne groups may be replaced by nitrogen atoms,

a 3,4-dihydro-isoquinolinyl, 1H-benzo[d][1,2]oxazinyl,

4H-benzo[e][1,3]oxazinyl, 4H-benzo[d][1,3]oxazinyl or

2H-benzo[1,4]oxazinyl group, wherein in each case

in the benzo moiety one to three methyne groups may be replaced by nitrogen atoms and in the heterocyclyl moiety a methylene group may be replaced by a carbonyl group,

a 4H-benzo[e][1,3]thiazinyl, 4H-benzo[d][1,3]thiazinyl or 2H-benzo[1,4]thiazinyl group, wherein in each case

in the benzo moiety one to three methyne groups may be replaced by nitrogen atoms and in the heterocyclyl moiety a methylene group may be replaced by a carbonyl group and a sulphur atom may be replaced by a sulphinyl or sulphonyl group,

a 2-oxo-2H-benzo[e][1,3]oxazinyl or 2,2-dioxo-1H-benzo[c][1,2]thiazinyl group, wherein in each case in the benzo moiety

one to three methyne groups may be replaced by nitrogen atoms,

a 2,3-dihydro-1H-benzo[e][1,4]diazepinyl, 4,5-dihydro-3H-benzo[b]-[1,4]diazepinyl or 5-oxo-4,5-dihydro-3H-benzo[e][1,4]diazepinyl group, wherein in each case

in the benzo moiety one to three methyne groups may be replaced by nitrogen atoms and in the heterocyclyl moiety a methylene group may be replaced by a carbonyl group,

a 2,3-dihydro-benzo[f][1,4]oxazepinyl or 2,3-dihydro-benzo[b][1,4]oxazepinyl group wherein in each case

in the benzo moiety one to three methyne groups may be replaced by nitrogen atoms and in the heterocyclyl moiety a methylene group may be replaced by a carbonyl group,

a 2,3-dihydro-benzo[f][1,4]thiazepinyl or 2,3-dihydro-benzo[b][1,4]thiazepinyl group, wherein in each case

in the benzo moiety one to three methyne groups may be replaced by nitrogen atoms and in the heterocyclyl moiety a methylene group may be replaced by a carbonyl group and a sulphur atom may be replaced by a sulphinyl or sulphonyl group,

a 5-oxo-4,5-dihydro-benzo[f][1,3,4]oxadiazepinyl group wherein in the benzo moiety

one to three methyne groups may be replaced by nitrogen atoms,

an 11H-dibenzo[b,e]azepinyl or 5H-dibenzo[a,d]cycloheptenyl group, wherein in each case

in the benzo moiety one to three methyne groups may be replaced by nitrogen atoms and the methylene group in the heterocyclyl moiety may be replaced by an oxygen or sulphur atom, a carbonyl, sulphinyl, sulphonyl or an imino group substituted by R_x, where

R_x denotes a hydrogen atom or a C_1-4-alkyl, C_2-4-alkenyl, C_2-4-alkynyl, C_3-6-cycloalkyl, C_3-6-cycloalkyl-C_1-3-alkyl, aryl, aryl-C_1-3-alkyl, hydroxy-C_2-4-alkyl, C_1-3-alkyloxy-C_2-4-alkyl, C_3-6-cycloalkyloxy-C_2-4-alkyl, amino-C_2-4-alkyl, C_1-3-alkylamino-C_2-4-alkyl, di-(C_1-3-alkyl)-amino-C_2-4-alkyl, C_1-3-alkyl-carbonyl, C_1-3-alkyloxy-carbonyl, C_1-3-alkyloxy-carbonyl-C_1-3-alkyl, aryl-carbonyl, C_1-3-alkyl-sulphonyl or aryl-sulphonyl group,

a 1,2,3,4-tetrahydro-phenanthridinyl, benzo[f]quinoxalinyl, 5H-dibenzo[d,f][1,3]diazepinyl, 5H-benzo[e]pyrrolo[1,2-a][1,4]diazepinyl, thieno[3,2-b][1,4]benzoxazepinyl or a 3-oxo-2,3-dihydro-isoindol-1-ylidene group, wherein in each case

in the benzo moiety one to three methyne groups may be replaced by nitrogen atoms,

a benzo[1,2,5]oxadiazolyl, dibenzofuranyl, Indolizinyl, 1H-perimidinyl, group,

a pyrazolo[1,5-c]quinazolinyl group or an imidazo[2,1-a]isoquinolinyl or imidazo[1,2-a]isoquinolinyl group

wherein the above-mentioned groups R_a may be substituted by the groups R¹⁰ to R¹³ and may additionally be substituted by a C_1-3-alkyl group and

R¹⁰ denotes a hydrogen atom,

a fluorine, chlorine, bromine or iodine atom,

a C_1-4-alkyl, hydroxy, or C_1-4-alkyloxy group,

a nitro, amino, C_1-3-alkylamino, di-(C_1-3-alkyl)amino, cyano-C_1-3-alkylamino, [N-(cyano-C_1-3-alkyl)-N-C_1-3-alkyl-amino], C_1-3-alkyloxy-carbonyl-C_1-3-alkylamino, pyrrolidin-1-yl, piperidin-1-yl, morpholin-4-yl, piperazin-1-yl, or 4-(C_1-3-alkyl)-piperazin-1-yl group,

a C_1-3-alkyl-carbonylamino, arylcarbonylamino, aryl-C_1-3-alkyl-carbonylamino, C_1-3-alkyloxy-carbonylamino, aminocarbonylamino, C_1-3-alkyl-aminocarbonylamino, di-(C_1-3-alkyl)aminocarbonylamino, pyrrolidin-1-yl-carbonylamino, piperidin-1-yl-carbonylamino, morpholin-4-yl-carbonylamino, piperazin-1-yl-carbonylamino or 4-(C_1-3-alkyl)-piperazin-1-yl-carbonylamino, C_1-3-alkyl-sulphonylamino, bis-(C_1-3-alkylsulphonyl)-amino, aminosulphonylamino, C_1-3-alkylamino-sulphonylamino, di-(C_1-3-alkyl)amino-sulphonylamino, pyrrolidin-1-yl-sulphonylamino, piperidin-1-yl-sulphonylamino, morpholin-4-yl-sulphonylamino, piperazin-1-yl-sulphonylamino or 4-(C_1-3-alkyl)-piperazin-1-yl-sulphonylamino, (C_1-3-alkylamino)thiocarbonylamino, (C_1-3-alkyloxy-carbonylamino)-carbonylamino, arylsulphonylamino or aryl-C_1-3-alkyl-sulphonylamino group,

an N-(C_1-3-alkyl)-C_1-3-alkyl-carbonylamino, N-(C_1-3-alkyl)-arylcarbonylamino, N-(C_1-3-alkyl)-aryl-C_1-3-alkyl-carbonylamino, N-(C_1-3-alkyl)-C_1-3-alkyloxy-carbonylamino, N-(aminocarbonyl)-C_1-3-alkylamino, N-(C_1-3-alkyl-aminocarbonyl)-C_1-3-alkylamino, N-[di-(C_1-3-alkyl)aminocarbonyl]-C_1-3-alkylamino, N-(C_1-3-alkyl)-C_1-3-alkyl-sulphonylamino, N-(C_1-3-alkyl)-arylsulphonylamino or N-(C_1-3-alkyl)-aryl-C_1-3-alkyl-sulphonylamino group,

a 2-oxo-imidazolidin-1-yl, 2,4-dioxo-imidazolidin-1-yl, 2,5-dioxo-imidazolidin-1-yl or 2-oxo-hexahydropyrimidin-1-yl group wherein the nitrogen atom in the 3 position may be substituted in each case by a methyl or ethyl group,

a cyano, carboxy, C_1-3-alkyloxy-carbonyl, aminocarbonyl, C_1-3-alkyl-aminocarbonyl, di-(C_1-3-alkyl)-aminocarbonyl, pyrrolidin-1-yl-carbonyl, piperidin-1-yl-carbonyl, morpholin-4-yl-carbonyl, piperazin-1-yl-carbonyl or 4-(C_1-3-alkyl)-piperazin-1-yl-carbonyl group,

a C_1-3-alkyl-carbonyl or an arylcarbonyl group,

a carboxy-C_1-3-alkyl, C_1-3-alkyloxy-carbonyl-C_1-3-alkyl, cyano-C_1-3-alkyl, aminocarbonyl-C_1-3-alkyl, C_1-3-alkyl-aminocarbonyl-C_1-3-alkyl, di-(C_1-3-alkyl)-aminocarbonyl-C_1-3-alkyl, pyrrolidin-1-yl-carbonyl-C_1-3-alkyl, piperidin-1-yl-carbonyl-C_1-3-alkyl, morpholin-4-yl-carbonyl-C_1-3-alkyl, piperazin-1-yl-carbonyl-C_1-3-alkyl or 4-(C_1-3-alkyl)-piperazin-1-yl-carbonyl-C_1-3-alkyl group,

a carboxy-C_1-3-alkyloxy, C_1-3-alkyloxy-carbonyl-C_1-3-alkyloxy, cyano-C_1-3-alkyloxy, aminocarbonyl-C_1-3-alkyloxy, C_1-3-alkyl-aminocarbonyl-C_1-3-alkyloxy, di-(C_1-3-alkyl)-aminocarbonyl-C_1-3-alkyloxy, pyrrolidin-1-yl-carbonyl-C_1-3-alkyloxy, piperidin-1-yl-carbonyl-C_1-3-alkyloxy, morpholin-4-yl-carbonyl-C_1-3-alkyl-oxy, piperazin-1-yl-carbonyl-C_1-3-alkyloxy or 4-(C_1-3-alkyl)-piperazin-1-yl-carbonyl-C_1-3-alkyloxy group,

a hydroxy-C_1-3-alkyl, C_1-3-alkyloxy-C_1-3-alkyl, amino-C_1-3-alkyl, C_1-3-alkylamino-C_1-3-alkyl, di-(C_1-3-alkyl)-amino-C_1-3-alkyl, pyrrolidin-1-yl-C_1-3-alkyl, piperidin-1-yl-C_1-3-alkyl, morpholin-4-yl-C_1-3-alkyl, piperazin-1-yl-C_1-3-alkyl, 4-(C_1-3-alkyl)-piperazin-1-yl-C_1-3-alkyl group,

a hydroxy-C_1-3-alkyloxy, C_1-3-alkyloxy-C_1-3-alkyloxy, C_1-3-alkylsulphanyl-C_1-3-alkyloxy, C_1-3-alkylsulphinyl-C_1-3-alkyloxy, C_1-3-alkylsulphonyl-C_1-3-alkyloxy, amino-C_1-3-alkyloxy, C_1-3-alkylamino-C_1-3-alkyloxy, di-(C_1-3-alkyl)-amino-C_1-3-alkyloxy, pyrrolidin-1-yl-C_1-3-alkyloxy, piperidin-1-yl-C_1-3-alkyloxy, morpholin-4-yl-C_1-3-alkyloxy, piperazin-1-yl-C_1-3-alkyloxy, 4-(C_1-3-alkyl)-piperazin-1-yl-C_1-3-alkyloxy group,

a mercapto, C_1-3-alkylsulphanyl, C_1-3-alkylsulphinyl, C_1-3-alkylsulphonyl, C_1-3-alkylsulphonyloxy, arylsulphonyloxy, trifluoromethylsulphanyl, trifluoromethylsulphinyl or trifluoromethylsulphonyl group,

a sulpho, aminosulphonyl, C_1-3-alkyl-aminosulphonyl, di-(C_1-3-alkyl)-aminosulphonyl, pyrrolidin-1-yl-sulphonyl, piperidin-1-yl-sulphonyl, morpholin-4-yl-sulphonyl, piperazin-1-yl-sulphonyl or 4-(C_1-3-alkyl)-piperazin-1-yl-sulphonyl group,

a methyl or methoxy group substituted by 1 to 3 fluorine atoms,

an ethyl or ethoxy group substituted by 1 to 5 fluorine atoms,

a C_2-4-alkenyl or C_2-4-alkynyl group,

a C_3-4-alkenyloxy or C_3-4-alkynyloxy group,

a C_3-6-cycloalkyl or C_3-6-cycloalkyloxy group,

a C_3-6-cycloalkyl-C_1-3-alkyl or C_3-6-cycloalkyl-C_1-3-alkyloxy group or

an aryl, aryloxy, aryl-C_1-3-alkyl or aryl-C_1-3-alkyloxy group,

R¹¹ and R¹², which may be identical or different, in each case denote a hydrogen atom, a fluorine, chlorine, bromine or iodine atom, a C_1-3-alkyl, trifluoromethyl, hydroxy or C_1-3-alkyloxy group or a cyano group, or

R¹¹ together with R², if they are bound to adjacent carbon atoms, also denote a methylenedioxy, difluoromethylenedioxy, ethylenedioxy or a straight-chain C_3-5-alkylene group and

R¹³ denotes a hydrogen atom, a fluorine, chlorine or bromine atom, a trifluoromethyl, C_1-3-alkyl or C_1-3-alkyloxy group,

R² denotes a hydrogen atom,

a C_1-6alkyl group,

a C_2-4-alkenyl group,

a C_3-4-alkynyl group,

a C_3-6-cycloalkyl group,

a C_3-6-cycloalkyl-C_1-3-alkyl group,

a tetrahydrofuran-3-yl, tetrahydropyran-3-yl, tetrahydropyran-4-yl, tetrahydrofuranylmethyl or tetrahydropyranylmethyl group,

an aryl group,

an aryl-C_1-4-alkyl group,

an aryl-C_2-3-alkenyl group,

an arylcarbonyl-C_1-2-alkyl group,

a heteroaryl-C_1-3-alkyl group,

a furanylcarbonylmethyl, thienylcarbonylmethyl, thiazolylcarbonylmethyl or pyridylcarbonylmethyl group,

a C_1-4-alkyl-carbonyl-C_1-2-alkyl group,

a C_3-6-cycloalkyl-carbonyl-C_1-2-alkyl group,

an aryl-A-C_1-3-alkyl group, wherein A denotes an oxygen or sulphur atom, —NH—, N(C_1-3-alkyl), sulphinyl or sulphonyl group,

a C_1-4-alkyl group substituted by a group R_b, wherein

R_b denotes a cyano, carboxy, C_1-3-alkyloxy-carbonyl, aminocarbonyl, C_1-3-alkylamino-carbonyl, di-(C_1-3-alkyl)-amino-carbonyl, pyrrolidin-1-ylcarbonyl, piperidin-1-ylcarbonyl, morpholin-4-ylcarbonyl, piperazin-1-ylcarbonyl, 4-methylpiperazin-1-ylcarbonyl or 4-ethylpiperazin-1-ylcarbonyl group,

or a C_2-4-alkyl group substituted by a group R_c, wherein

R_c denotes a hydroxy, C_1-3-alkyloxy, amino, C_1-3-alkylamino, di-(C_1-3-alkyl)-amino, pyrrolidin-1-yl, piperidin-1-yl, morpholin-4-yl, piperazin-1-yl, 4-methyl-piperazin-1-yl or 4-ethyl-piperazin-1-yl group and is isolated from the cyclic nitrogen atom in the 3 position of the xanthine structure by at least two carbon atoms,

R³ denotes a C_3-8-alkyl group,

a C_1-3-alkyl group substituted by a group R_d, wherein

R_d denotes a C_3-7-cycloalkyl group optionally substituted by one or two C_1-3-alkyl groups,

a C_5-7-cycloalkenyl group optionally substituted by one or two C_1-3-alkyl groups,

an aryl group or

a furanyl, thienyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl-, pyridyl, pyridazinyl, pyrimidyl or pyrazinyl group, wherein the above-mentioned heterocyclic groups may be substituted in each case by one or two C_1-3-alkyl groups or by a fluorine, chlorine, bromine or iodine atom or by a trifluoromethyl, cyano or C_1-3-alkyloxy group,

a C_3-8-alkenyl group,

a C_3-6-alkenyl group substituted by a fluorine, chlorine or bromine atom or a trifluoromethyl group,

a C_3-8-alkynyl group,

an aryl group or

an aryl-C_2-4-alkenyl group, and

R⁴ denotes an azetidin-1-yl or pyrrolidin-1-yl group which is substituted in the 3 position by an amino, C_1-3-alkylamino or a di-(C_1-3-alkyl)amino group and may additionally be substituted by one or two C_1-3-alkyl groups,

a piperidin-1-yl or hexahydroazepin-1-yl group which is substituted in the 3 position or in the 4 position by an amino, C_1-3-alkylamino or a di-(C_1-3-alkyl)amino group and may additionally be substituted by one or two C_1-3-alkyl groups,

a 3-amino-piperidin-1-yl group wherein the piperidin-1-yl-moiety is additionally substituted by an aminocarbonyl, C_1-2-alkyl-aminocarbonyl, di-(C_1-2-alkyl)aminocarbonyl, pyrrolidin-1-yl-carbonyl, (2-cyano-pyrrolidin-1-yl)-carbonyl, thiazolidin-3-yl-carbonyl, (4-cyano-thiazolidin-3-yl)carbonyl, piperidin-1-ylcarbonyl or morpholin-4-ylcarbonyl group,

a 3-amino-piperidin-1-yl group wherein the piperidin-1-yl-moiety is additionally substituted in the 4 position or in the 5 position by a hydroxy or methoxy group,

a 3-amino-piperidin-1-yl group wherein the methylene group in 2 position or in 6 position is replaced by a carbonyl group,

a piperidin-1-yl or hexahydroazepin-1-yl group substituted in the 3 position by an amino, C_1-3-alkylamino or di-(C_1-3-alkyl)-amino group, wherein in each case two hydrogen atoms on the carbon skeleton of the piperidin-1-yl or hexahydroazepin-1-yl group are replaced by a straight-chain alkylene bridge, wherein this bridge contains 2 to 5 carbon atoms, if the two hydrogen atoms are located on the same carbon atom, or contains 1 to 4 carbon atoms if the hydrogen atoms are located on adjacent carbon atoms, or contains 1 to 4 carbon atoms, if the hydrogen atoms are located on carbon atoms which by are separated by one atom, or contains 1 to 3 carbon atoms if the two hydrogen atoms are located on carbon atoms which are separated by two atoms,

an azetidin-1-yl, pyrrolidin-1-yl, piperidin-1-yl or hexahydroazepin-1-yl group which is substituted by an amino-C_1-3-alkyl, C_1-3-alkylamino-C_1-3-alkyl or a di-(C_1-3-alkyl)amino-C_1-3-alkyl group,

a piperazin-1-yl or [1,4]diazepan-1-yl group optionally substituted on the carbon skeleton by one or two C_1-3-alkyl groups,

a 3-imino-piperazin-1-yl, 3-imino-[1,4]diazepan-1-yl or 5-imino-[1,4]diazepan-1-yl group optionally substituted on the carbon skeleton by one or two C_1-3-alkyl groups,

a [1,4]diazepan-1-yl group optionally substituted by one or two C_1-3-alkyl groups, which is substituted by an amino group in the 6 position,

a C_3-7-cycloalkyl group which is substituted by an amino, C_1-3-alkylamino or di-(C_1-3-alkyl)-amino group,

a C_3-7-cycloalkyl group which is substituted by an amino-C_1-3-alkyl, C_1-3-alkylamino-C_1-3-alkyl or a di-(C_1-3-alkyl)amino-C_1-3-alkyl group,

a C_3-7-cycloalkyl-C_1-2-alkyl group wherein the cycloalkyl moiety is substituted by an amino, C_1-3-alkylamino or di-(C_1-3-alkyl)-amino group,

a C_3-7-cycloalkyl-C_1-2-alkyl group wherein the cycloalkyl moiety is substituted by an amino-C_1-3-alkyl, C_1-3-alkylamino-C_1-3-alkyl or a di-(C_1-3-alkyl)amino-C_1-3-alkyl group,

a C_3-7-cycloalkylamino group wherein the cycloalkyl moiety is substituted by an amino, C_1-3-alkylamino or di-(C_1-3-alkyl)-amino group, wherein the two nitrogen atoms on the cycloalkyl moiety are separated from one another by at least two carbon atoms,

an N-(C_3-7-cycloalkyl)-N-(C_1-3-alkyl)-amino group wherein the cycloalkyl moiety is substituted by an amino, C_1-3-alkylamino or di-(C_1-3-alkyl)-amino group, wherein the two nitrogen atoms on the cycloalkyl moiety are separated from one another by at least two carbon atoms,

a C_3-7-cycloalkylamino group wherein the cycloalkyl moiety is substituted by an amino-C_1-3-alkyl, C_1-3-alkylamino-C_1-3-alkyl or a di-(C_1-3-alkyl)amino-C_1-3-alkyl group,

an N-(C_3-7-cycloalkyl)-N-(C_1-3-alkyl)-amino group wherein the cycloalkyl moiety is substituted by an amino-C_1-3-alkyl, C_1-3-alkylamino-C_1-3-alkyl or a di-(C_1-3-alkyl)amino-C_1-3-alkyl group,

a C_3-7-cycloalkyl-C_1-2-alkyl-amino group wherein the cycloalkyl moiety is substituted by an amino, C_1-3-alkylamino or di-(C_1-3-alkyl)-amino group,

an N-(C_3-7-cycloalkyl-C_1-2-alkyl)-N-(C_1-2-alkyl)-amino group wherein the cycloalkyl moiety is substituted by an amino, C_1-3-alkylamino or di-(C_1-3-alkyl)-amino group,

a C_3-7-cycloalkyl-C_1-2-alkyl-amino group wherein the cycloalkyl moiety is substituted by an amino-C_1-3-alkyl, C_1-3-alkylamino-C_1-3-alkyl or a di-(C_1-3-alkyl)amino-C_1-3-alkyl group,

an N-(C_3-7-cycloalkyl-C_1-2-alkyl)-N-(C_1-2-alkyl)-amino group wherein the cycloalkyl moiety is substituted by an amino-C_1-3-alkyl, C_1-3-alkylamino-C_1-3-alkyl or a di-(C_1-3-alkyl)amino-C_1-3-alkyl group,

an R¹⁹—C_2-4-alkylamino group wherein R¹⁹ is separated from the nitrogen atom of the C_2-4-alkylamino moiety by at least two carbon atoms and

R¹⁹ denotes an amino, C_1-3-alkylamino or di-(C_1-3-alkyl)-amino group,

an R¹⁹—C_2-4-alkylamino group wherein the nitrogen atom of the C_2-4-alkylamino moiety is substituted by a C_1-3-alkyl group and R¹⁹ is separated from the nitrogen atom of the C_2-4-alkylamino moiety by at least two carbon atoms, wherein R¹⁹ is as hereinbefore defined,

an amino group substituted by the group R²⁰ wherein

R²⁰ denotes an azetidin-3-yl, azetidin-2-ylmethyl, azetidin-3-ylmethyl, pyrrolidin-3-yl, pyrrolidin-2-ylmethyl, pyrrolidin-3-ylmethyl, piperidin-3-yl, piperidin-4-yl, piperidin-2-ylmethyl, piperidin-3-ylmethyl or piperidin-4-ylmethyl group, wherein the groups mentioned for R²⁰ may each be substituted by one or two C_1-3-alkyl groups,

an amino group substituted by the group R²⁰ and a C_1-3-alkyl group wherein R²⁰ is as hereinbefore defined, wherein the groups mentioned for R²⁰ may each be substituted by one or two C_1-3-alkyl groups,

a R¹⁹—C_3-4-alkyl group wherein the C_3-4-alkyl moiety is straight-chain and may additionally be substituted by one or two C_1-3-alkyl groups, wherein R¹⁹ is as hereinbefore defined,

a 3-amino-2-oxo-piperidin-5-yl or 3-amino-2-oxo-1-methyl-piperidin-5-yl group,

a pyrrolidin-3-yl, piperidin-3-yl, piperidin-4-yl, hexahydroazepin-3-yl or hexahydroazepin-4-yl group which is substituted in the 1 position by an amino, C_1-3-alkylamino or di-(C_1-3-alkyl)amino group,

or an azetidin-2-yl-C_1-2-alkyl, azetidin-3-yl-C_1-2-alkyl, pyrrolidin-2-yl-C_1-2-alkyl, pyrrolidin-3-yl, pyrrolidin-3-yl-C_1-2-alkyl, piperidin-2-yl-C_1-2-alkyl, piperidin-3-yl, piperidin-3-yl-C_1-2-alkyl, piperidin-4-yl or piperidin-4-yl-C_1-2-alkyl group, wherein the above-mentioned groups may each be substituted by one or two C_1-3-alkyl groups,

wherein by the aryl groups mentioned in the definition of the above groups are meant phenyl or naphthyl groups, which may be mono- or disubstituted by R_h independently of one another, where the substituents are identical or different and R_h denotes a fluorine, chlorine, bromine or iodine atom, a trifluoromethyl, cyano, nitro, amino, aminocarbonyl, aminosulphonyl, methylsulphonyl, acetylamino, methylsulphonylamino, C_1-3-alkyl, cyclopropyl, ethenyl, ethynyl, hydroxy, C_1-3-alkyloxy, difluoromethoxy or trifluoromethoxy group,

by the heteroaryl groups mentioned in the definitions of the above mentioned groups are meant a pyrrolyl, furanyl, thienyl, pyridyl, indolyl, benzofuranyl, benzothiophenyl, quinolinyl or isoquinolinyl group,

or a pyrrolyl, furanyl, thienyl or pyridyl group wherein one or two methyne groups are replaced by nitrogen atoms,

or an indolyl, benzofuranyl, benzothiophenyl, quinolinyl or isoquinolinyl group wherein one to three methyne groups are replaced by nitrogen atoms,

and the above-mentioned heteroaryl groups may be mono- or disubstituted by R_h, wherein the substituents may be identical or different and R_h is as hereinbefore defined,

and, unless otherwise specified, the above-mentioned alkyl, alkenyl and alkynyl groups may be straight-chain or branched,

or the tautomers, enantiomers, diastereomers, the mixtures thereof, the prodrugs thereof and the salts thereof.