# Patent

## Title
Arylglycinamide derivatives, method of producing said derivatives and pharmaceutical compositions containing these compounds

## Abstract

The invention relates to new arylglycinamide derivatives of general formula I




and the pharmaceutically acceptable salts thereof, wherein R1 and R2 together with the N to which they are bound form a ring of the formula





in which

    
    
        R3, R4, R5, Ar, R6, R7, R8, R9, R10, R11, r, s and t have the meanings given in the specification and the preparation and use thereof. The new compounds are valuable neurokinin (tachykinin) antagonists.

## Background
RELATED APPLICATIONS
This application is a continuation of application Ser. No. 09/703,758, filed Nov. 1, 2000, which is a continuation of application Ser. No. 09/142,271, filed Nov. 30, 1998, now abandoned, which is a national stage entry under 35 U.S.C. § 371 of PCT/EP97/01038, filed Mar. 3, 1997.


The invention relates to new arylglycinamide derivatives of general formula




and the pharmaceutically acceptable salts thereof, processes for preparing them and pharmaceutical compositions containing these compounds. The compounds are valuable neurokinin (tachykinin) antagonists.

The abbreviations used in this specification and claims are explained as follows:
















CDI
Carbonyldiimidazole



DCCI
Dicyclohexylcarbodiimide



HOBt
1-Hydroxybenzotriazole



THF
Tetrahydrofuran



DMF
Dimethylformamide



RT
Room temperature



DMAP
4-Dimethylaminopyridine



TBTU
O-Benzotriazolyl-tetramethyluronium-




tetrafluoroborate










The formulae are shown in simplified form. In representing the compounds, for example, all the CH3-substituents are represented by a hyphen and CH is represented by, thus, for example:




The invention relates to new arylglycinamide derivatives of general formula I




or the pharmaceutically acceptable salts thereof, wherein

    
    
        Ar denotes unsubstituted or mono- to penta-substituted phenyl, or unsubstituted or mono- or disubstituted naphthyl [wherein the substituents of the phenyl and naphthyl independently of one another denote halogen (F, Cl, Br, I), (C1-4)alkyl, O—(C1-4)alkyl, CF3, OCF3 or NR12R13 (wherein R12 and R13 independently of one another denote H, methyl or acetyl)] or Ar is phenyl substituted by —O—CH2—O— or —O—(CH2)2—O—;
        R1 and R2 together with the N to which they are bound denote a ring of the formula
    
    






wherein

    r, s and t are 2 or 3;
    R6 denotes
    H,
    (C1-5)alkyl,
    (C3-5)alkenyl,
    propynyl,
    hydroxy(C2-4)alkyl,
    methoxy(C2-4)alkyl,
    di(C1-3)alkylamino(C2-4)alkyl,
    amino(C2-4)alkyl,
    amino,
    di(C1-3)alkylamino,
    monofluoro- to perfluoro(C1-2)alkyl,
    N-methylpiperidinyl,
    pyridyl,
    pyrimidinyl,
    pyrazinyl,
    pyridazinyl
    or the group —CH2—C(O)NR14R15,

wherein

    R14 is H or (C1-4)alkyl and
    R15 is H, (C1-4)alkyl, (C3-6)cycloalkyl, hydroxy(C2-4)alkyl, alkoxy(C2-3)alkyl, phenyl(C1-4)alkyl, or R14 and R15 together with the N to which they are bound form a ring (1-pyrrolidinyl, piperidino, morpholino or 1-methylpiperazin-4-yl);
    R7 has one of the definitions (a) to (d),
    (a) hydroxy
    (b) 4-piperidinopiperidyl,






wherein R16 and R17 independently of one another denote

    H,
    (C1-4)alkyl,
    (C3-6)cycloalkyl,
    hydroxy(C2-4)alkyl,
    (C1-3)alkoxy(C2-4)alkyl,
    phenyl(C1-4)alkyl or
    di(C1-3)alkylamino(C2-4)alkyl,
    or if R16 is H or (C1-4)alkyl,
    R17 may also be —CH2C(O)NR18R19, wherein R18 and R19 are defined as R14 and R15 hereinbefore;






    
    
         wherein R20 denotes
        H,
        (C1-4)alkyl,
        (C4-6)cycloalkyl or
        —CH2C(O)NR21R22,
        wherein R21 and R22 are defined as R14 and R15 hereinbefore;
        R8 is H
    
    
    R9 and R10 independently of each other denote (C1-4)alkyl;
    R11 denotes
    H,
    (C1-5)alkyl,
    (C3-5)alkenyl,
    propynyl,
    hydroxy(C2-4)alkyl,
    methoxy(C2-3)alkyl,
    di(C1-3)alkylamino(C2-3)alkyl,
    amino(C2-3)alkyl,
    amino,
    di(C1-3)alkylamino,
    monofluoro- to perfluoro(C1-2)alkyl,
    N-methylpiperidinyl,
    pyridyl,
    pyrimidinyl,
    pyrazinyl,
    pyridazinyl
    or the group —CH2—C(O)NR23R24,

wherein R23 and R24 are defined as R14 and R15 hereinbefore;
    
        R3 denotes H, (C1-4)alkyl, unsubstituted or mono- to trisubstituted phenyl, wherein the substituents independently of one another denote halogen (F, Cl, Br, I), (C1-4)alkyl, O—(C1-4)alkyl, CF3, OCF3 or NR25R26 (wherein R25 and R26 independently of one another denote H, methyl or acetyl);
        R4 denotes phenyl(C1-4)alkyl or naphthyl(C1-4)alkyl, wherein phenyl may be substituted by 1 to 3 substituents, wherein the substituents independently of one another denote halogen (F, Cl, Br, I), (C1-4)alkyl, O—(C1-4)alkyl, CF3, OCF3 or NR27R28 (wherein R27 and R28 independently of one another denote H, methyl or acetyl);

and

        R5 denotes H, (C1-4)alkyl, (C3-6)cycloalkyl, CH2COOH, CH2C(O)NH2, OH or phenyl(C1-4)alkyl.
    
    


Preferred compounds of general formula I are those wherein

    
    
        Ar denotes unsubstituted or mono- or disubstituted phenyl, or unsubstituted naphthyl, or Ar is phenyl substituted by —O—CH2—O— or —O—(CH2)2—O—;
    
    
    R1 and R2 together with the N to which they are bound denote a ring of the formula






wherein

    r is 2 or 3 and
    s and t are 2;
    R6, R7, R8, R9, R10 and R11 are as hereinbefore defined;
    
        R3 is H or (C1-4)alkyl,
        R4 denotes phenyl(C1-4)alkyl or naphthyl(C1-4)alkyl, wherein phenyl may be substituted by 1 or 2 substituents, wherein the substituents independently of one another are halogen (F, Cl, Br, I), (C1-4)alkyl, O—(C1-4)alkyl, CF3 or OCF3;

and

        R5 denotes H, (C1-4)alkyl, (C3-6)cycloalkyl, OH or (C1-4)alkylphenyl.
    
    


Particular mention should be made of compounds of formula I wherein

    
    
        Ar is unsubstituted or mono- or disubstituted phenyl, or unsubstituted naphthyl [wherein the substituents of the phenyl independently of one another are halogen (F, Cl, Br, I), methyl, methoxy, CF3 or OCF3] or Ar is phenyl substituted by —O—CH2—O— or —O—(CH2)2—O—;

particularly those wherein Ar is phenyl, naphthyl, phenyl substituted in position 3 and/or 4 by methoxy or halogen, or phenyl in which positions 2 and 3 or 3 and 4 are linked by —O—CH2—O—, preferably those compounds wherein

    
    
    Ar is phenyl,
    phenyl substituted by methoxy in positions 3 and 4 or phenyl wherein positions 3 and 4 or 2 and 3 are linked by —O—CH2—O—.


Of the compounds defined above, special mention should be made of those wherein, in the ring




    r is 2 or 3 and
    R6 denotes
    H,
    (C1-5)alkyl,
    (C3-5)alkenyl,
    propynyl,
    hydroxy(C2-4)alkyl,
    methoxy(C2-4)alkyl,
    di(C1-3)alkylamino(C2-4)alkyl,
    amino(C2-4)alkyl,
    amino,
    di(C1-3)alkylamino,
    monofluoro- to perfluoro(C1-2)alkyl,
    N-methylpiperidinyl,
    pyridyl,
    pyrimidinyl,

or







particularly those wherein

    r is 3 and R6 is methyl;

and those wherein

    r is 2 and
    R6 is
    H,
    (C1-4)alkyl,
    propenyl,
    propynyl,
    hydroxy(C2-3)alkyl,
    methoxyethyl,
    di(C1-2)alkylamino(C2-3)alkyl,
    aminoethyl,
    amino,
    dimethylamino,
    CH2CF3,
    N-methylpiperidinyl,
    pyridyl,
    pyrimidinyl,

or







preferably those wherein

    r is 2 and
    R6 is H, (C1-3)alkyl, allyl, 2-propynyl, —CH2CH2OCH3, —CH2CH2N(CH3)2, N-methylpiperidinyl, 2-pyrimidinyl

or







particularly those wherein

    r is 2 and
    R6 is H, CH3, C3H7, CH(CH3)2, CH2CH2OH, CH2CH2OCH3 or CH2C2N(CH3)2.


Of the compounds defined above, mention should also be made of those wherein

    R1 and R2 together with the N to which they are bound form the ring






wherein R8 is H and

    R7 is OH






wherein R16 and R17 independently of one another denote:

    H
    (C1-3)alkyl,






    (CH2)nOH wherein n is 2, 3 or 4
    (CH2)2OCH3 
    —(CH2)nPh wherein n is 2 or 4
    (CH2)2N(CH3)2 






particularly those wherein

    R16 and R17 are both CH3 or C2H5 or
    R16 is H or CH3 and R17 is
    (C1-3)alkyl,






    (CH2)2OH,
    (CH2)4OH or






and those wherein

    R7 denotes






     N(CH3)2 






     or






especially those wherein

    R1 and R2 together with the N to which they are bound form the ring






wherein

    (a) R8 is H and
    
        R7 is
    
    






wherein R16 and R17 both represent CH3, C2H5 l or CH2CH2OH or

    R16 is H or CH3 and R17 is (C1-3)alkyl,






    (CH2)2OH or
    (CH2)4OH or
    (b) R8 is H and
    
        R7 denotes
    
    






Of the compounds defined above, mention should also be made of those wherein

    R1 and R2 together with the N to which they are bound form the ring






Of the compounds defined above, special mention should also be made of those wherein

    R1 and R2 together with the N to which they are bound form the ring






wherein R11 is H or (C1-3)alkyl, particularly those wherein

    R11 is —CH(CH3)2.


Of the compounds defined above, the ones of particular interest are those wherein R3 is H;
and/or


    
    
        R4 denotes phenyl(C1-4)alkyl, wherein phenyl may be substituted by 1 or 2 substituents, wherein the substituents independently of one another denote halogen (F, Cl, Br, I), (C1-4)alkyl, O—(C1-4)alkyl, CF3 or OCF3;

and/or

        R5 denotes H, (C1-4)alkyl, (C3-6)cycloalkyl, —OH or phenyl(C1-4)alkyl,

particularly those wherein

    
    
    R4 denotes phenyl(C2-4)alkyl, wherein the substituents are in positions 3 and/or 5 of the phenyl ring and/or
    R5 is H, methyl, OH or phenethyl,

preferably those wherein







and R5 is methyl.

Compounds of general formula I may have acid groups, chiefly carboxyl groups, and/or basic groups such as amino functions, for example. Compounds of general formula I may therefore be present either as internal salts, as salts with pharmaceutically acceptable inorganic acids such as hydrochloric acid, sulphuric acid, phosphoric acid, sulphonic acid or organic acids (such as maleic acid, fumaric acid, citric acid, tartaric acid or acetic acid) or as salts with pharmaceutically acceptable bases such as alkali or alkaline earth metal hydroxides or carbonates, zinc or ammonium hydroxides or organic amines such as dimethylamine, triethylamine, triethanolamine, etc.
The compounds according to the invention may occur as racemates but may also be obtained as pure enantiomers, i.e. in the (R)- or (S)-form.
The term naphthyl used hereinbefore includes both 1-naphthyl and 2-naphthyl.
Test results for compounds according to the invention:
The receptor affinity for the NK1-receptor (substance P-receptor) is determined on human lymphoblastoma cells (IM-9) with cloned NK1-receptors, by measuring the displacement of 125I-labelled substance P. The K1-values thus obtained show the efficacy of the compounds:















Ki [nM]



















Example 1
1.2



Example 2
1.0



Example 3
19



Example 4
1.4



Example 5
1.5



Example 8
1.8



Example 9
2.5



Example 11
3.8



Example 12
5.0



Example 13
2.4



Example 15
0.98



Example 16
0.90



Example 17
7.75



Example 18
0.96



Example 19
1.17



Example 20
2.0



Example 22
2.2



Example 23
2.5



Example 24
2.2



Example 25
6.0



Example 26
1.6



Example 28
1.3



Example 30
1.8



Example 32
1.3



Example 33
7.4



Example 34
2.9



Example 47
1.7



Example 55
1.25



Example 63
1.4



Example 64
1.1



Example 65
5.7



Example 73
2.0



Example 74
1.5



Example 75
0.44



Example 76
2.0










The compounds according to the invention are valuable neurokinin (tachykinin) antagonists which have both substance P antagonism and also neurokinin A and neurokinin B antagonistic properties. They are useful for the treatment and prevention of neurokinin-mediated diseases:

    for the treatment or prevention of inflammatory and allergic diseases of the respiratory tract, such as asthma, chronic bronchitis, hyperreactive respiratory tract, emphysema, rhinitis and cough,
    and of the eyes, such as conjunctivitis and iritis,
    of the skin, such as dermatitis in contact eczema, urticaria, psoriasis, sunburn, insect bites and stings, itching, sensitive or hypersensitive skin,
    of the gastrointestinal tract, such as gastric and duodenal ulcers, ulcerative colitis, Crohn's disease, irritable bowel and Hirschsprung's disease,
    of the joints, such as rheumatoid arthritis, reactive arthritis and Reiter syndrome;
    for treating diseases of the central nervous system such as dementia, Alzheimer's disease, schizophrenia, psychoses, depression, headache (e.g. migraine or tension headaches), epilepsy, Parkinson's disease and stroke;
    for treating herpes zoster and postherpetic pain, tumours, collagenoses, dysfunction of the deferent urinary tract, haemorrhoids, nausea and vomiting, caused for example by radiation or cytostatic therapy or motion and pain of all kinds.


The invention therefore also relates to the use of the compounds according to the invention as therapeutic agents and pharmaceutical preparations which contain these compounds. They are preferably used in humans. The compounds according to the invention may be administered by intravenous, subcutaneous, intramuscular, intraperitoneal or intranasal route, by inhalation, by transdermal route, optionally aided by iontophoresis or enhancers known from the literature, and by oral route.
For parenteral administration the compounds of formula I or the physiologically acceptable salts thereof, possibly with the conventional substances such as solubilisers, emulsifiers or other adjuvants, are dissolved, suspended or emulsified. Solvents which may be used include: water, physiological saline solutions or alcohols, e.g. ethanol, propanediol or glycerol, sugar solutions such as glucose or mannitol solutions or a mixture of several solvents.
In addition, the compounds may be administered by means of implants, e.g. of polylactide, polyglycolide or polyhydroxybutyric acid or intranasal preparations.
The oral efficacy of compounds of general formula I can be demonstrated by the following standard test:
Inhibition of lowering of blood pressure caused by NK1 in anaesthetised guinea pigs.
Guinea pigs weighing 300–500 grams were anaesthetised with pentobarbital (50 mg/kg i.p.), intubated and artificially ventilated. They were ventilated with 10 ml/kg of air at a frequency of 60 breaths per minute. The carotid artery was canulated and the arterial blood pressure was recorded. A polyethylene tube was inserted into the jugular vein for the intravenous supply of substances.
A temporary reduction in blood pressure was brought about at intervals of 10 minutes by intravenous administration of the NK1-agonist [βAla4, Sar9, Met (O2)11]Sp(4-11)




in a dose of 0.2 μmol/kg. After the blood pressure thus produced had been measured, the test compound was introduced into the duodenum and the NK1-agonist was again injected every 10 minutes.

The results were expressed as a % inhibition of the reduction in blood pressure caused by the NK1-agonist specified.
In a dosage of 1 mg/kg (administered into the duodenum) the compound of Example 1 inhibited the lowering of blood pressure caused by the NK1-agonist by 80%.
The compounds according to the invention can be produced using generally known methods.
The compounds may be prepared in various ways. The two most common procedures are represented by the following diagram:




Method A. The carboxylic acid may be linked to the amine HN(R5)R4 by various methods. Conventional methods are coupling processes such as those used in peptide chemistry. A coupling reagent such as TBTU, DCCI/HOBt, CDI, etc., is added to the coupling partners in substantially equivalent quantities. Suitable solvents are DMF, THF, CH2Cl2, CHCl3, acetonitrile or other inert solvents or mixtures thereof. The suitable temperature range is between −50° C. and +120° C., preferably between 0° C. and 40° C.
The carboxylic acid may also initially be converted into the corresponding acid halide by known methods using SOCl2, SO2Cl2, PCl3, PCl5 or PBr3 or mixtures thereof, and the acid halide is then reacted with the amine HN(R5)R4 in an inert solvent such as CH2Cl2, THF or dioxane at temperatures between −50° C. and +100° C., typically at 0° to 20° C.
Another alternative is to convert the carboxylic acid initially into the alkylester, usually the methylester, by known methods and this ester is then reacted with the amine HN(R5)R4 in an inert solvent such as DMF, dioxane or THF. The reaction temperatures are between 20° C. and 150° C., typically between 50° C. and 120° C. The reaction may also be carried out in a pressurized container.
Method B. Here, the α-halo-arylacetamide derivative obtained by known methods is reacted with the amine R1(R2)NH, thereby cleaving hydrogen halide. Inorganic bases such as K2CO3, NaHCO3 or CaCO3 or organic bases such as triethylamine, Hünig base, pyridine or DMAP are used to mop up the cleaved (or excess) hydrogen halide, or an excess of the amine R1(R2)NH may be used. DMF, THF, dioxane or other inert solvents are used. The temperature range for the reaction is from 0 to 100° C., typically between 10 and 80° C.
Method C. The compounds according to the invention wherein R5 is not H may also be prepared as follows: first of all, the corresponding compound in which R5 is H is synthesised using method A or B. Then, N-alkylation is carried out as follows in order to introduce alkyl, cycloalkyl or CH2COOH. The compounds according to the invention wherein R5 is H are deprotonated with an equivalent quantity of NaH, NaNH2, KOH, NaOCH3 or another strong base. Anhydrous inert solvents such as THF, dioxane or diethylether are used for this. Then the corresponding alkylating agent is added slowly in the form of the corresponding halide, tosylate or mesylate. The reaction is carried out at a temperature within the range from −50° C. to +100° C., typically between 0° C. and +50° C.


EXAMPLE 1




Mp.: 105–115° C.
FAD-MS: (M+H)+=516.3.
1st step: 0.71 q of 1-isopropylpiperazine were dissolved in 55 ml of anhydrous DMF, mixed with 0.64 g of Na2CO3, stirred for 20 minutes at RT and then cooled to 5° C. 1.15 g of methyl (R,S)-α-bromophenylacetate were added and the suspension was stirred overnight at RT. The precipitate was filtered off and the filtrate was evaporated down. The residue was taken up in ethyl acetate, extracted twice with 10% KHCO3 solution and once with saturated NaCl solution. The organic phase was dried over Na2SO4, filtered and evaporated down, to yield 1.23 g of methyl (R,S)-1-isopropyl-4-(2-phenylacetate)piperazine as a viscous oil.
Yield: about 89%.
2nd step: 1.23 g of the product from the 1st step were dissolved in 10 ml of methanol and 10 ml of THF, mixed with 10 ml of 1N NaCH and the mixture was stirred overnight at ambient temperature. The clear reaction solution was neutralised by the addition of 10 ml of 1N HCl, evaporated to dryness, the residue was treated with DMF and the solid was separated by suction filtering. The filtrate was evaporated down and the residue was triturated with ether, the solid substance removed by suction filtering and dried in a desiccator. In this way, 1.1 g of (R,S)-1-i-propyl-4-(2-phenylacetic acid)piperazine were obtained as a solid white substance.
Yield: 92%.
3rd step: 0.37 g of the product of the 2nd step and 0.42 g of N-methyl-3,5-bis-(trifluoromethyl)phenylethylamine were dissolved in 14 ml of DMF and adjusted to pH 8.5 by the addition of about 0.4 ml of TEA. 0.48 g of TBTU were added and the mixture was stirred overnight at room temperature. The clear reaction solution was evaporated down in vacuo, the residue was stirred with NaHCO3 solution and extracted twice with ethyl acetate. The combined organic phases were filtered and the filtrate was evaporated down. The residue was chromatographed over silica gel using CH2Cl2/MeOH (9:1) as eluant. The uniform fractions obtained were evaporated down, dissolved in a little MeOH, acidified with ethereal HCl and evaporated down again. The residue was triturated with ether and dried in a desiccator. 0.58 g of (R,S)-1-i-propyl-4-[2-phenylacetic acid-N-methyl-N-(3,5-bistrifluoromethylphenylethyl)]-amide dihydrochloride were obtained as a solid white substance.
Yield: 75%.
The other compounds of the invention may be prepared analogously, e.g. the following:
EXAMPLE 2




EXAMPLE 3




EXAMPLE 4




EXAMPLE 5




EXAMPLE 6




EXAMPLE 7




EXAMPLE 8




EXAMPLE 9




EXAMPLE 11




EXAMPLE 12




EXAMPLE 13




EXAMPLE 15




EXAMPLE 16




EXAMPLE 17




EXAMPLE 18




EXAMPLE 19




EXAMPLE 20




EXAMPLE 22




EXAMPLE 23




EXAMPLE 24




EXAMPLE 25




EXAMPLE 26




EXAMPLE 27




EXAMPLE 28




EXAMPLE 29




EXAMPLE 30




EXAMPLE 31




EXAMPLE 32




EXAMPLE 33




EXAMPLE 34




EXAMPLE 35




EXAMPLE 36




EXAMPLE 37




EXAMPLE 38




EXAMPLE 39




EXAMPLE 40




EXAMPLE 41




EXAMPLE 42




EXAMPLE 43




EXAMPLE 44




EXAMPLE 45




EXAMPLE 46




EXAMPLE 47




EXAMPLE 48




EXAMPLE 49




EXAMPLE 50




EXAMPLE 51




EXAMPLE 53




EXAMPLE 54




EXAMPLE 55




EXAMPLE 56




EXAMPLE 57




EXAMPLE 58




EXAMPLE 59




EXAMPLE 60




EXAMPLE 61




EXAMPLE 63




EXAMPLE 64




EXAMPLE 65




EXAMPLE 66




EXAMPLE 67




EXAMPLE 68




EXAMPLE 69




EXAMPLE 70




EXAMPLE 71




EXAMPLE 72




EXAMPLE 73




EXAMPLE 74




EXAMPLE 75




EXAMPLE 76




Of these compounds, the compounds of Examples 1 and 8 are preferred.
In the foregoing representations of the formulae, the CH3 groups are not drawn in full.
Compound 1, for example, contains a methyl group as the group R5.










Pharmaceutical preparations















Injectable solution











200
mg
of active substance*




1.2
mg
of monopotassium dihydrogen




phosphate = KH2PO4


0.2
mg
of disodium hydrogen phosphate =
 {close oversize brace} 
 (buffer)




Na2HPO4.2H2O


94
mg
sodium chloride


or


 {close oversize brace} 
 (isotonic agents)


520
mg
glucose


4
mg
albumin

(protease protection)


q.s.

sodium hydroxide solution





 {close oversize brace} 
 ad pH 6


q.s.

hydrochloric acid


ad 10
ml
water for injections







Injectable solution











200
mg
active substance*




94
mg
sodium chloride


or


520
mg
glucose


4
mg
albumin


q.s.

sodium hydroxide solution





 {close oversize brace} 
 ad pH 9


q.s.

hydrochloric acid


ad 10
ml
water for injections







Lyophilisate









200
mg
of active substance*


520
mg
of mannitol (isotonic agent/framework




agent)


4
mg
albumin








Solvent 1
for lyophilisate









10
ml
of water for injections








Solvent 2
for lyophilisate









20
mg
of Polysorbate ®80 = Tween ®80




(surfactant)


10
ml
of water for injections





*Active substance: compound according to the invention, e.g. one of Examples 1 to 76


Dosage for humans weighing 67 kg: 1 to 500 mg

## Claims

1. A compound of Formula I




wherein:
Ar is an unsubstituted or mono- to penta-substituted phenyl, or unsubstituted or mono- or disubstituted naphthyl, wherein the substituents of the phenyl and naphthyl group of Ar independently of one another are selected from F, Cl, Br, I, (C1-4)alkyl, O—(C1-4)alkyl, CF3, OCF3, or NR12R13 wherein R12 and R13 independently of one another are H, methyl, or acetyl, or Ar is phenyl substituted by —O—CH2—O— or —O—(CH2)2—O—;
R1 and R2 together with the N to which they are bound are a ring of the formula




R7 has one of the definitions (a) to (d):
(a) hydroxy,
(b) 4-piperidinopiperidyl,






 wherein R16 and R17 independently of one another are H, (C1-4)alkyl, (C3-6)cycloalkyl, hydroxy(C2-4)alkyl, (C1-3)alkoxy(C2-4)alkyl, phenyl(C1-4)alkyl, or di(C1-3)alkylamino(C2-4)alkyl, or if R16 is H or (C1-4)alkyl, R17 is also —CH2C(O)NR18R19, wherein:
R18 is H or (C1-4)alkyl, and
R19 is H, (C1-4)alkyl, (C3-6)cycloalkyl, hydroxy(C2-4)alkyl, alkoxy(C2-3)alkyl, phenyl(C1-4)alkyl, or R18 and R19 together with the N to which they are bound form a 1-pyrrolidinyl, piperidino, morpholino, or 1-methylpiperazin-4-yl ring;








 wherein R20 is H, (C1-4)alkyl, (C4-6)cycloalkyl, or —CH2C(O)NR21R22, wherein:
R21 is H or (C1-4)alkyl, and
R22 is H, (C1-4)alkyl, (C3-6)cycloalkyl, hydroxy(C2-4)alkyl, alkoxy(C2-3)alkyl, phenyl(C1-4)alkyl;


R3 is H or (C1-4alkyl;
R4 is phenyl(C1-4)alkyl or naphthyl(C1-4)alkyl, wherein phenyl is optionally substituted by 1 to 3 substituents, wherein the substituents independently of one another are F, Cl, Br, I, (C1-4)alkyl, O—(C1-4)alkyl, CF3, OCF3, or NR27R28 wherein R27 and R28 independently of one another are H, methyl, or acetyl; and
R5 is H, (C1-4)alkyl, (C3-6)cycloalkyl, CH2COOH, CH2C(O)NH2, OH or phenyl(C1-4)alkyl,

or a pharmaceutically acceptable salt thereof.

2. The compound according to claim 1, wherein:
Ar is unsubstituted or mono- or disubstituted phenyl, or unsubstituted naphthyl, or Ar is phenyl substituted by —O—CH2—O— or —O—(CH2)2—O—;
R3 is H or (C1-4)alkyl;
R4 is phenyl(C1-4)alkyl or naphthyl(C1-4)alkyl, wherein phenyl is optionally substituted by 1 or 2 substituents, wherein the substituents independently of one another are F, Cl, Br, I, (C1-4)alkyl, O—(C1-4)alkyl, CF3, or OCF3; and
R5 is H, (C1-4)alkyl, (C3-6)cycloalkyl, OH, or phenyl(C1-4)alkyl.

3. The compound according to claim 1, wherein:
Ar is unsubstituted or mono- or disubstituted phenyl, or unsubstituted naphthyl, wherein the substituents of the phenyl independently on one another are F, Cl, Br, I, methyl, methoxy, CF3, or OCF3, or Ar is phenyl substituted by —O—CH2—O— or —O—(CH2)2—O—.

4. The compound according to claim 3, wherein:
Ar is phenyl, naphthyl, phenyl substituted by F, Cl, Br, I, or methoxy in position 3 and/or 4, or phenyl wherein positions 2 and 3 or 3 and 4 are linked by —O—CH2—O—.

5. The compound according to claim 4, wherein:
Ar is phenyl, phenyl substituted by methoxy in positions 3 and 4, or phenyl in which positions 3 and 4 or 2 and 3 are linked by —O—CH2—O—.

6. The compound according to claim 1, wherein R7 is hydroxy.

7. The compound according to claim 1, wherein R7 is 4-piperidinopiperidyl.

8. The compound according to claim 1, wherein:
R7is





wherein R16 and R17 independently of one another are H, (C1-4)alkyl, (C3-6)cycloalkyl, hydroxy(C2-4)alkyl, (C1-3)alkoxy(C2-4)alkyl, phenyl(C1-4)alkyl, or di(C1-3)alkylamino(C2-4)alkyl, or if R16 is H or (C1-4)alkyl, R17 is also —CH2C(O)NR18R19.

9. The compound according to claim 1, wherein:
R7 is





wherein R20 is H, (C1-4)alkyl, (C4-6)cycloalkyl, or —CH2C(O)NR21R22.

10. The compound according to claim 1, wherein:
R7 is





wherein R16 and R17 independently of one another are: H; (C1-3)alkyl;




(CH2)mOH, wherein m is 2, 3, or 4; (CH2)2OCH3; —(CH2)nPh, wherein n is 2, 3, or 4; or (CH2)2N(CH3)2.

11. The compound according to claim 10, wherein R16 and R17 are both CH3 or C2H5, or R16 is H or CH3 and R17 is (C1-3)alkyl,




(CH2)2OH, or (CH2)4OH.

12. The compound according to claim 1, wherein:
R7 is

13. The compound according to claim 1, wherein:
R7 is





wherein R16 and R17 are each CH3, C2H5, or CH2CH2OH, or R16 is H or CH3, and R17 is (C1-3)alkyl,




(CH2)2OH, or (CH2)4OH.

14. The compound according claim 1, wherein R7 is N(CH3)2.

15. The compound according claim 1, wherein:
R7is





wherein R20 is (C1-4)alkyl.

16. The compound according to claim 1, wherein:
R7 is





wherein R20 is (C4-6)cycloalkyl.

17. The compound according claim 1, wherein R3 is H.

18. The compound according claim 1, wherein:
R4 is phenyl(C1-4)alkyl, wherein phenyl is optionally substituted by 1 or 2 substituents, in which the substituents independently of one another are F, Cl, Br, I, (C1-4)alkyl, O—(C1-4)alkyl, CF3, or OCF3; and
R5 is H, (C1-4)alkyl, (C3-6)cycloalkyl, —OH, or phenyl(C1-4)alkyl.

19. The compound according to claim 18, wherein:
R4 is phenyl(C2-4)alkyl, wherein the substituents are in positions 3 and/or 5 of the phenyl ring; and
R5 is H, methyl, OH, or phenethyl.

20. The compound according to claim 19, wherein:
R4 is




 and
R5 is methyl.

21. A method of treating diseases of the central nervous system selected from dementia, Alzheimer's disease, schizophrenia, psychosis, depression, headache, epilepsy, Parkinson's disease, and stroke in a warm-blooded animal, the method comprising administering to the animal a therapeutically effective amount of the compound according to claim 1.