HK1098146B - New polysubstituted 1,1-pyridylaminocyclopropanamine compounds, a process for their preparation and pharmaceutical compositions containing them - Google Patents

Description

Polysubstituted 1, 1-pyridylamino-cyclopropylamine compounds, process for their preparation and pharmaceutical compositions containing them

The present invention relates to novel polysubstituted 1, 1 pyridinylcyclopropylamine compounds, to a process for their preparation and to pharmaceutical compositions containing them.

From the pharmacological point of view, the compounds of the invention are particularly valuable due to their specific interaction with central nicotinic receptors of the α 4 β 2 type, and can be used for the treatment of neuropathologies associated with brain aging, mood disorders, pain and tobacco withdrawal.

Aging of the population due to an increase in life expectancy at birth causes a significant increase in the incidence of age-related neuropathologies, particularly alzheimer's disease. The main clinical manifestations of brain aging and in particular of age-related neuropathologies are deficits in memory and cognitive function that can lead to dementia. It has been widely demonstrated that among various neurotransmitters, acetylcholine plays an important role in memory function, and cholinergic neuronal pathways are extensively damaged in certain neurodegenerative diseases, or are poorly activated in the case of brain aging. Thus, numerous therapeutic approaches aim to prevent the destruction of neurotransmitters or to find alternatives to defective neurotransmitters by inhibiting acetylcholinesterase. In the latter case, the recommended cholinergic agonist is a muscarinic agonist, which is specific for the postsynaptic M1 receptor.

It has recently been shown that cholinergic damage associated with Alzheimer's disease has a greater effect on neurons with nicotinic receptors than on neurons with muscarinic receptors (Schroder et al, "Alzheimer disease: therapeutic strategies", Birkhauser Boston, 1994, 1781-185). Numerous studies have further demonstrated that nicotine possesses memory-promoting properties (prog. neuropsychopharmacol., 1992, 16, 181-. Moreover, nicotine has neuroprotective effects against stimulant agents such as glutamate (Brain res, 1994, 664, 181-187).

All these findings are most likely linked to epidemiological studies demonstrating that the incidence of alzheimer's and parkinson's disease is low in smokers. In addition, several studies have demonstrated the value of nicotine in the treatment of mood disorders such as depression, anxiety or schizophrenia. Finally, nicotine has been shown to have analgesic properties. All of the therapeutic characteristics of nicotine as well as those of other nicotinic agents are based on activity at central receptors, which differ structurally and pharmacologically from peripheral receptors (muscle and ganglia). Central receptors of the α 4 β 2 type are most representative in the central nervous system and are involved in the major nicotinic therapeutic effects (Lif sci., 1995, 56, 545-570).

Several documents such as Synlett, 1999, 7, 1053-; med, chem, 1985, 28(12), 1953-; 1970, 13(5), 820-; 1972, 15(10), 1003-; J.am.chem.Soc., 1987, 109(13), 4036-one 4046, or a few patents or patent applications such as DE 3608727, EP 124208 or WO 94/10158 describe and claim compounds containing 1, 1-or 1, 2-disubstituted cyclopropane moieties. All these references do not describe or suggest that these compounds have specific pharmacological activity towards nicotinic receptors, and more particularly towards central nicotinic receptors of the α 4 β 2 type, which is a novel property of the compounds described by the applicant. Patent application EP 1170281 describes 1, 1-or 1, 2-disubstituted cyclopropane compounds as nicotinic ligands.

The compounds of the invention are therefore novel and represent potent central receptor-selective nicotinic ligands of the α 4 β 2 subtype. They are therefore useful in the treatment of memory impairment associated with brain aging and with neurodegenerative diseases such as alzheimer's disease, parkinson's disease, pick's disease, korsakoff's psychosis and frontal and subcortical dementia, as well as in the treatment of mood disorders, tourette's syndrome, attention deficit hyperactivity disorder, tobacco withdrawal and pain.

The invention more particularly relates to compounds of formula (I):

wherein:

n represents an integer of from 1 to 6 inclusive,

R₁and R₂May be identical or different and independently of one another represent a hydrogen atom, a linear or branched chain (C)₁-C₆) The alkyl or alkyl moiety may be a straight or branched chain aryl- (C)₁-C₆) An alkyl group, a carboxyl group,

R₃and R₄May be identical or different and independently of one another represent a hydrogen atom or a linear or branched (C)₁-C₆) An alkyl group, a carboxyl group,

R₅and R₆May be identical or different and independently of one another represent a hydrogen atom or a linear or branched (C)₁-C₆) Alkyl, halogen, hydroxy, straight or branched chain (C)₁-C₆) Alkoxy, cyano, nitro, straight or branched chain (C)₂-C₆) Acyl, straight or branched (C)₁-C₆) Alkoxycarbonyl, straight-chain or branched (C)₁-C₆) Trihaloalkyl or straight or branched chain (C)₁-C₆) Trihaloalkoxy or optionally substituted by one or two straight or branched chains (C)₁-C₆) An amino group substituted with an alkyl group,

R₇represents a hydrogen atom, a straight chain or a branched chain (C)₁-C₆) The alkyl or alkyl moiety may be a straight or branched chain aryl- (C)₁-C₆) An alkyl group.

Aryl is understood to be phenyl, biphenyl, naphthyl, dihydronaphthyl, tetrahydronaphthyl, 1, 3 indanyl or indenyl, each of which may optionally be substituted by one or more identical or different groups selected from: halogen atom, straight or branched chain (C)₁-C₆) Alkyl, hydroxy, cyano, nitro, straight or branched chain (C)₁-C₆) Alkoxy, straight or branched chain (C)₂-C₇) Acyl, straight or branched (C)₁-C₆) Alkoxycarbonyl, straight-chain or branched (C)₁-C₆) Trihaloalkyl and straight or branched chain (C)₁-C₆) Trihaloalkoxy and optionally one or two straight or branched chains (C)₁-C₆) Amino substituted by alkyl.

Preferred compounds of the invention are those in which n has an integer value of 1.

Preferred substituents R according to the invention₁And R₂Is a hydrogen atom and a straight or branched chain (C)₁-C₆) An alkyl group.

More preferably, the substituents R preferred according to the invention₁And R₂Are a hydrogen atom and a methyl group.

Preferred substituents R according to the invention₃And R₄Is a hydrogen atom.

Preferred substituents R according to the invention₅And R₆Is a hydrogen atom, straight or branched (C)₁-C₆) Alkyl groups and halogen atoms.

Advantageously, a preferred compound of the invention is that wherein R is₅Represents a hydrogen atom and R₆Represents a straight chain or branched chain (C)₁-C₆) Alkyl groups and halogen atoms.

More advantageously, a preferred compound of the invention is that wherein R is₅RepresentsHydrogen atom and R₆A compound representing a methyl group and a halogen atom.

Preferred substituents R according to the invention₇Is a hydrogen atom or a linear or branched chain (C)₁-C₆) An alkyl group.

Advantageously, the substituents R preferred according to the invention₇Is a hydrogen atom or a methyl group.

In a particularly advantageous manner, preferred compounds of the invention are:

n- { [1- (methylamino) cyclopropyl ] methyl } pyridin-3-amine,

N-methyl-N- { [1- (methylamino) cyclopropyl ] methyl } pyridin-3-amine,

n- (1-aminocyclopropyl) methyl ] pyridin-3-amine,

n- { [1- (dimethylamino) cyclopropyl ] methyl } pyridin-3-amine,

n- [ (1-aminocyclopropyl) methyl ] -N-methylpyridine- -amine,

n- { [1- (dimethylamino) cyclopropyl ] methyl } -N-methylpyridin-3-amine,

6-chloro-N- { [1- (methylamino) cyclopropyl ] methyl } pyridin-3-amine,

6-chloro-N-methyl-N- { [1- (methylamino) cyclopropyl ] methyl } pyridin-3-amine,

6-bromo-N- { [1- (methylamino) cyclopropyl ] methyl } pyridin-3-amine,

6-bromo-N-methyl-N- { [1- (methylamino) cyclopropyl ] methyl } pyridin-3-amine,

6-methyl-N- { [1- (methylamino) cyclopropyl ] methyl } pyridin-3-amine,

n, 6-dimethyl-N- { [1- (methylamino) cyclopropyl ] methyl } pyridin-3-amine.

Among the pharmaceutically acceptable acids, mention may be made, without implying any limitation, of hydrochloric acid, hydrobromic acid, sulfuric acid, phosphoric acid, acetic acid, trifluoroacetic acid, lactic acid, pyruvic acid, malonic acid, succinic acid, glutaric acid, fumaric acid, tartaric acid, maleic acid, citric acid, ascorbic acid, oxalic acid, methanesulfonic acid, camphoric acid, etc.

Among the pharmaceutically acceptable bases that may be mentioned, without implying any limitation, are sodium hydroxide, potassium hydroxide, triethylamine, tert-butylamine, etc.

Enantiomers, diastereomers and pharmaceutically acceptable acid or base addition salts of the preferred compounds form an integral part of the invention.

The invention also relates to a process for the preparation of compounds of formula (I), characterized in that compounds of formula (II) are used as starting materials:

wherein R is₃、R₄And n is as defined for formula (I),

reacting the compound of formula (II) with diphenylphosphorylazide in toluene in the presence of triethyleneamine, followed by the addition of t-butanol to yield the compound of formula (III):

wherein R is₃、R₄And n is as defined above, and,

reacting a compound of formula (III) with a compound of formula (IV) in the presence of a base in an anhydrous solvent to produce a compound of formula (V):

R′₁-Hal (IV)

wherein Hal represents a halogen atom, and R'₁Represents a linear or branched chain selected from (C)₁-C₆) Alkyl and alkyl groupAryl radicals which may be linear or branched in part- (C)₁-C₆) The radical of an alkyl group,

wherein R is₃、R₄N and R'₁As defined above, the above-mentioned,

the compounds of formula (III) and formula (V) constitute compounds of formula (VI):

wherein R is₃、R₄And n is as defined above and R₁As defined for formula (I),

placing the compound of formula (VI) in a reducing agent to produce a compound of formula (VII):

wherein R is₃、R₄N and R1 are as defined above,

subjecting a compound of formula (VII) to the usual oxidizing agents in organic synthesis to produce a compound of formula (VIII):

wherein R is₃、R₄N and R₁As defined above, the above-mentioned,

reacting a compound of formula (VIII) with a compound of formula (IX) in the presence of sodium triacetoxyborohydride to yield a compound of formula (X):

wherein R is₅And R₆As defined for formula (I),

wherein R is₃、R₄、R₅、R₆N and R₁As defined above, the above-mentioned,

reacting a compound of formula (X):

or in dioxane in the presence of an acid to give a compound of formula (I/a) as a particular example of a compound of formula (I):

wherein R is₁、R₃、R₄、R₅、R₆And n is as defined above, and,

reacting a compound of formula (I/a):

or in aqueous formaldehyde and formic acid to give the compounds of formula (I/b) as a particular case of the compounds of formula (I):

wherein R is₁、R₃、R₄、R₅、R₆And n is as defined above, and,

-or with a compound of formula (XI) in the presence of a base in an anhydrous solvent to give a compound of formula (I/c) as a special case of the compound of formula (I):

R′₂-Hal (XI)

wherein Hal is as defined above, and R'₂Represents a linear or branched chain selected from (C)₁-C₆) Alkyl and alkyl moieties may be straight or branched aryl- (C)₁-C₆) The radical of an alkyl group,

wherein R is₁、R₃、R₄、R₅、R₆N and R'₂As defined above, the above-mentioned,

or when R is₁When representing a benzyl group, in hydrochloric acid and palladium on carbon to give a compound of formula (I/d) as a special case of a compound of formula (I):

wherein R is₃、R₄、R₅、R₆And n is as defined above, and,

treating the compound of formula (I/d) with formic acid and formaldehyde in aqueous solution to give a compound of formula (I/e) as a particular example of a compound of formula (I):

wherein R is₃、R₄、R₅、R₆And n is as defined above, and,

the compounds of formulae (I/b), (I/c), (I/d) and (I/e) constitute compounds of formula [ I/f ] as a special case of the compounds of formula (I):

wherein R is₁、R₂、R₃、R₄、R₅、R₆And n is as defined above, and,

reacting a compound of formula (I/f) with a compound of formula (XII) in the presence of a coupling agent, followed by reduction with an amide to give a compound of formula (I/g) as a particular example of a compound of formula (I):

R′₇-COOH (XII)

wherein R'₇Represents a linear or branched chain selected from (C)₁-C₅) Alkyl and alkyl moieties may be straight or branched aryl- (C)₁-C₅) The radical of an alkyl group,

wherein R is₁、R₂、R₃、R₄、R₅、R₆And n is as defined above, and R ″)₇Represents a linear or branched chain selected from (C)₁-C₆) Alkyl and alkyl moieties may be straight or branched aryl- (C)₁-C₆) The radical of an alkyl group,

-or in dimethylformamide in the presence of carbonyldiimidazole and formic acid to give the compound of formula (XIII):

wherein R is₁、R₃、R₄、R₅、R₆And n is as defined above, and,

reacting a compound of formula (XIII) with borane sulfide complex in tetrahydrofuran to yield a compound of formula (XIV):

wherein R is₁、R₃、R₄、R₅、R₆And n is as defined above, and,

the compound of formula (XIV) is reacted with an acid in dioxane under the same reaction conditions as for the compound of formula (X) to give a compound of formula (I/h) as a particular example of the compound of formula (I):

wherein R is₁、R₃、R₄、R₅、R₆And n is as defined above, and,

when R is₁(ii) when represents a benzyl group, subjecting the compound of formula (I/h) to the same reaction conditions as for the compound of formula (I/a) to give a compound of formula (I/I) as a specific example of the compound of formula (I):

wherein R is₃、R₄、R₅、R₆And n is as defined above, and,

subjecting the compound of formula (I/I) to the same reaction conditions as for the compound of formula (I/d) to give a compound of formula (I/j) as a specific example of the compound of formula (I):

wherein R is₃、R₄、R₅、R₆And n is as defined above, and,

the compounds of formulae (I/a) to (I/j) collectively constitute the totality of the compounds of the present invention, which may be purified, if desired, according to conventional purification techniques, separated into their different isomers according to conventional separation techniques, and converted, if desired, into their pharmaceutically acceptable acid or base addition salts.

The formulae (II), (IV), (IX), (XI) and (XII) are either commercial products or are obtainable according to conventional methods of organic synthesis which are well known to the person skilled in the art.

In general, isomers of the compounds of the invention are to be understood as optical isomers, such as enantiomers and diastereomers. More particularly, the pure enantiomeric forms of the compounds of the present invention can be separated starting from a mixture of enantiomers which is reacted with a releasable racemate separating agent, which is itself in the form of the pure enantiomer, which makes it possible to obtain the corresponding diastereomer. The diastereomers may then be separated according to separation techniques well known to those skilled in the art, such as crystallization or chromatography, and the separating agent removed using conventional techniques of organic chemistry to provide the pure enantiomers.

The compounds of the invention, which are present as a mixture of diastereomers, are separated into their purified form using conventional separation techniques, such as chromatography.

In certain particular instances, the methods of preparing the compounds of the present invention may result in the preferential formation of one enantiomer or diastereomer over the other.

Due to their pharmacological activity as nicotinic ligands and selectivity for the α 4 β 2 subtype receptors, the compounds of the invention are useful in the treatment of memory impairment associated with brain aging and with neurodegenerative diseases such as alzheimer's disease, parkinson's disease, pick's disease, korsakoff's psychosis and frontal and subcortical dementia, as well as in the treatment of mood disorders, tourette's syndrome, attention deficit hyperactivity disorder, tobacco withdrawal and pain.

The present invention also relates to pharmaceutical compositions comprising, as active ingredient, at least one compound of formula (I), its isomers or addition salts of its pharmaceutically acceptable acids or bases, alone or in association with one or more pharmaceutically acceptable inert non-toxic excipients or carriers.

Pharmaceutical compositions of the invention for parenteral injection include, inter alia, aqueous or non-aqueous sterile solutions, dispersions, suspensions and emulsions, and also sterile powders for reconstitution into injectable solutions or dispersions.

Pharmaceutical compositions of the invention for oral administration in solid form include inter alia tablets or dragees, sublingual tablets, sachets, gelatin capsules and granules, and for liquid forms for oral, nasal, lingual or ocular administration include inter alia emulsions, solutions, suspensions, drops, syrups and aerosols.

Pharmaceutical compositions for rectal or vaginal administration are preferably suppositories, and pharmaceutical compositions for transdermal or transdermal administration include, inter alia, powders, aerosols, creams, ointments, gels and patches.

The aforementioned pharmaceutical compositions illustrate the invention but do not limit it in any way.

Among the pharmaceutically acceptable inert non-toxic excipients or carriers, mention may be made, by way of non-limiting example, of diluents, solvents, preservatives, wetting agents, emulsifiers, dispersing agents, binders, swelling agents, disintegrating agents, retarding agents, lubricants, absorbents, suspending agents, colorants, flavoring agents, and the like.

Useful dosages will vary depending upon the age and weight of the patient, the route of administration and pharmaceutical composition employed, the nature and severity of the disease, and the implementation of any relevant treatment. The dosage is 1mg to 500mg daily, administered in one or more divided doses.

The following examples illustrate the invention but are not intended to limit it in any way.

The starting materials used are known products or products obtained according to known operating methods. Various preparative methods may synthesize intermediates useful in preparing the compounds of the present invention.

The structure of the compounds described in the examples and preparations can be determined according to the usual spectrophotometric techniques (infrared, nuclear magnetic resonance, mass spectrometry).

Melting points were determined using either Kofler hot plates or hot plates under a microscope. When the compound is in the salt form, the melting point and elemental microanalysis given refers to the salt form of the product.

Preparation method 1: 1- (formyl) cyclopropyl (methyl) carbamic acid tert-butyl ester

Step 1: 1- [ (tert-Butoxycarbonyl) amino ] cyclopropanecarboxylic acid methyl ester

A solution of 80g of 1- (methoxycarbonyl) cyclopropanecarboxylic acid and 78ml of triethylamine in 550ml of toluene (152 g of diphenylphosphorylazide were added) was heated to 80 ℃. When the evolution of gas had ceased, the temperature was adjusted to 50 ℃ and 61g of tert-butanol were added. After 7 hours reaction at 80 ℃, the mixture was concentrated. The residue was dissolved in ether and saturated Na₂CO₃The solution is washed, then with a 1N hydrochloric acid solution and finally with NaHCO₃And (4) washing the solution. After drying and evaporation of the organic phase, the residue is dissolved in 300ml of cyclopropane and concentrated to dryness. The residue obtained is triturated in pentane, filtered and then dried, isolating the expected product.

Step 2: 1- [ (tert-Butoxycarbonyl) (methyl) amino ] cyclopropanecarboxylic acid methyl ester

24.7g of sodium hydride are added portionwise to a solution of 99.7g of the compound obtained in step 1 above in 1.7L of anhydrous dimethylformamide cooled to 5 ℃. After stirring at 5 ℃ for 15 minutes and at room temperature for 3 hours, 38.2ml of methyl iodide was added dropwise. After a reaction time of 20 hours, the mixture was evaporated. The residue was dissolved in ether and then worked up in the conventional manner. Chromatography on silica gel (dichloromethane) gave the expected product.

And step 3: 1- (hydroxymethyl) cyclopropyl (methyl) carbamic acid tert-butyl ester

100ml of a 2M lithium borohydride solution in tetrahydrofuran was added to a solution of 23g of the compound obtained in step 2 above in 100ml of tetrahydrofuran. After the reaction mixture was stirred at room temperature for 20 hours, it was refluxed for 8 hours, then cooled to 0 ℃, hydrolyzed, diluted with ether, separated, dried and concentrated. The residue is chromatographed on silica gel (dichloromethane/tetrahydrofuran: 95/5) to give the expected product.

And 4, step 4: 1-formylcyclopropyl (methyl) carbamic acid tert-butyl ester

33.5g of dimethyl sulfoxide are added over the course of 20 minutes at-60 ℃ to a solution of 25.8g of oxalyl chloride in 430ml of dichloromethane. After stirring at-60 ℃ for 20 minutes, a mixture containing 34.3g of the above compound in step 3 in 100ml of dichloromethane was added at-60 ℃ over 1 hour. After stirring for 30 minutes at-60 ℃ 81ml of triethylamine are poured in over 20 minutes at-60 ℃ and the temperature is subsequently raised again to 20 ℃. 60ml of water are poured in, the separation is carried out and the aqueous phase is then extracted several times with dichloromethane. The combined dichloromethane phases were washed with saturated sodium chloride solution and sucked dry over sodium sulfate and subsequently concentrated to dryness. Chromatography on silica gel (dichloromethane/tetrahydrofuran: 97/3) gives 31.2g of the expected product. The preparation method 2: benzyl {1- [ (pyridin-3-ylamino) methyl ] cyclopropyl } -carbamic acid tert-butyl ester

Step 1: 1- [ benzyl (tert-butyloxycarbonyl) amino ] cyclopropanecarboxylic acid methyl ester

To a three-necked flask were added 21.5g of the compound of preparation 1, step 1, and 216ml of dimethylformamide. 4.8g of 60% sodium hydride in oil were added at 20 ℃. Stirred at room temperature for 2 hours. 18ml of benzyl bromide were added over 20 minutes and stirred at room temperature for 20 hours. Heated at 60 ℃ for 1 hour and then concentrated to dryness. The residue was dissolved in ether and washed with 10% sodium carbonate solution and then with 10% lithium chloride solution. Suck dry over sodium sulfate and concentrate to dryness. Chromatography on silica gel (dichloromethane/cyclopropane: 85/15, then pure dichloromethane) gives 71.3g of the expected product in colloidal form. Step 2: benzyl [1- (hydroxymethyl) cyclopropyl ] carbamic acid tert-butyl ester

To a mixture of 21.2g of the compound obtained in step 1 above in 100ml of tetrahydrofuran was added 2M lithium borohydride in 70ml of THF at 20 ℃ over 20 minutes. Stirred at 20 ℃ for 20 hours and then refluxed for 1 hour. Cooled to 5 ℃ and then carefully hydrolysed with 24ml of water and 20ml of 10% aqueous sodium carbonate solution. 500ml of ether are added, separation is carried out and the aqueous phase is extracted with ether. The combined ether phases were sucked dry over sodium sulfate and concentrated to dryness. 19.3g of the expected product are obtained.

Melting point: 68 ℃.

And step 3: benzyl (1-formylcyclopropyl) carbamic acid tert-butyl ester

10.3ml of dimethyl sulfoxide are poured into a mixture of 7.49ml of oxalyl chloride and 145ml of dichloromethane at-60 ℃ over 20 minutes. The mixture was stirred at-60 ℃ for 20 minutes. 19.3g of the compound obtained in step 2 above were poured in over 1 hour and stirred at-60 ℃ for 30 minutes. 27.3ml of triethylamine are poured in and stirred for 20 minutes at-60 ℃. The temperature was raised to 20 ℃ and 50.6ml of water were poured in. After stirring for 10 minutes at 20 ℃, separation was carried out and the aqueous phase was extracted with dichloromethane. The combined organic phases were sucked dry over sodium sulfate and concentrated to dryness. Chromatography on silica gel (dichloromethane) gives 16.45g of the expected product.

Melting point: 67 ℃.

And 4, step 4: benzyl {1- [ (pyridin-3-ylamino) methyl ] cyclopropyl } carbamic acid tert-butyl ester

To 2.5L of methylene chloride were added 38.8g of the compound obtained in the above step 3, 14.7g of 3-aminopyridine and 282ml of 3And (3) a molecular sieve. Stirring was carried out at 20 ℃ for 2 hours, followed by the addition of 149g of sodium triacetoxyborohydride. Stirred at 20 ℃ for 4 days. Filtration was followed by washing the filtrate with 10% aqueous sodium carbonate solution, blotting over sodium sulfate and concentration to dryness. Chromatography on silica gel (dichloromethane/tetrahydrofuran: 90/10) gives 36.2g of the expected product in the form of a gum.

Example 1: n- { [1- (methylamino) cyclopropyl ] methyl } pyridin-3-amine dihydrochloride

Step 1: methyl {1- [ (pyridin-3-ylamino) methyl ] cyclopropyl } carbamic acid tert-butyl ester

To a solution containing 3.0g of the product of preparation 1, 300ml of methylene chloride, 1.56g of 3-aminopyridine and 30ml of 3 at 20 ℃ under a nitrogen atmosphereTo the mixture of molecular sieves was added 15.9g of sodium triacetoxyborohydride. The reaction mixture was stirred at 20 ℃ for 2 days and filtered. The filtrate was washed with 10% sodium carbonate solution, sucked dry over sodium sulfate and concentrated to dryness. Chromatography on silica gel (toluene/ethanol: 95/5) gives 3.0g of the expected product.

Step 2: n- { [1- (methylamino) cyclopropyl ] methyl } pyridin-3-amine dihydrochloride

To a solution of 1.0g of the product obtained in step 1 above in 50ml of dioxane was poured 14ml of dioxane containing 4N hydrochloric acid at 20 ℃. Stirred at room temperature for 20 hours. Ether was added and the insoluble material was filtered off with suction and dissolved in ethanol. Concentrate to dryness and triturate the residue in ether. The crystals were filtered off with suction and dried in vacuo at 30 ℃. 0.78g of the expected product is obtained.

Mass spectrum (ESI): m/z 178.1Th ([ M + H)]⁺)。

Melting point: 190 ℃ and 195 ℃.

Example 2: N-methyl-N- { [1- (methylamino) cyclopropyl ] methyl } pyridin-3-amine dihydrochloride

Step 1: (1- { [ formyl (pyridin-3-yl) amino ] methyl } cyclopropyl (methyl) -carbamic acid tert-butyl ester

A solution of 23.8g of carboxydiimidazole and 30ml of DMF is poured at 5 ℃ into a solution of 6.14g of formic acid and 30ml of DMF. Stirred at 5 ℃ for 1 hour and then at 20 ℃ for 3 hours. Cooled to 5 ℃ and then poured into a mixture containing 7.4g of the product obtained in step 1 of example 1 and 75ml of DMF. Stir 20 h at 20 ℃ and concentrate to dryness at 1 torr. The residue was taken up in dichloromethane, washed with 10% aqueous sodium carbonate solution, dried over sodium sulfate and concentrated to dryness. Chromatography on silica gel (toluene/ethanol: 95/5) gives 6.2g of the expected product.

Step 2: N-methyl-N- { [1- (methylamino) cyclopropyl ] methyl } pyridin-3-amine dihydrochloride

To a mixture containing 2.0g of the compound obtained in step 1 above and 20ml of tetrahydrofuran was poured 1.6ml of 10M borane methyl sulfide complex at 0 ℃. The temperature was raised to 40 ℃ and refluxed for 3 hours. Cooled to 0 ℃ and poured into 3ml of methanol. Stir for 1 hour, then slowly pour into hydrochloric acid methanol until pH < 2. Gas evolution was observed. When gas evolution ceased, the reaction was refluxed for 3 hours. Concentrating to dryness. The residue was dissolved with dichloromethane and subsequently washed with 1N sodium hydroxide solution. Suck dry over sodium sulfate and concentrate to dryness. The residue is chromatographed on silica gel (dichloromethane/methanol/15N ammonium hydroxide: 95/5/0.5). 0.7g of base dissolved in ether was obtained. Ethereal hydrochloric acid was added until an acidic pH was reached. Precipitation was observed. The ether was separated and discarded and the gum was triturated in pure ether. Crystallization was observed. The crystals were filtered off with suction and dried at 40 ℃ at 1 torr. 0.8g of the expected product is obtained.

Mass spectrum (ESI): 192.1Th ([ M + H) M/z]⁺)

Melting point: 180 ℃ and 184 DEG C

Example 3: n- { [ (1-benzylamino) cyclopropyl ] methyl } pyridin-3-amine

To a mixture containing 7.15g of the compound of preparation 2, 80ml of dioxane and 80ml of methanol was poured 4M hydrochloric acid in 50ml of dioxane at 20 ℃. Stirred at 20 ℃ for 3 days. Concentrating to dryness, and adding methanol. Again, concentration was performed, and methanol addition and distillation were repeated two more times. The residue was dissolved in 300ml of methanol and 80ml of silica gel were added. Concentrate to dryness (paste formation). Chromatography on silica gel (CH)₂Cl₂Methanol: 80/20) 6.6g of the expected product are obtained as gum.

Example 4: n- [ (1-aminocyclopropyl) methyl ] pyridin-3-amine dihydrochloride

4.0g of the compound from example 3 are dissolved in 200ml of ethanol and 1ml of 11.8N hydrochloric acid are added. Concentrate to dryness and dissolve the residue in 200ml ethanol and reflux. After cooling, 200ml of cyclohexane were added, followed by 1.2g of 10% palladium on carbon under nitrogen. Reflux for 20 hours, then filter and concentrate to dryness. The residue was dissolved in 200ml ethanol and 5ml water and concentrated again. The residue was dissolved in methanol and 32ml of silica gel (paste formed) were added. Concentrating to dryness. Chromatography on 550ml of silica gel (dichloromethane/methanol: 80/20). The compound obtained was dissolved in 12ml of 35% sodium hydroxide solution. Extracted several times with ether, the combined ether phases are sucked dry over sodium sulfate and concentrated to dryness. The residue was dissolved in ethanol, ethanol hydrochloride was added until pH1 was reached, and concentrated to dryness. The residue was dissolved by heating in isopropanol and cooled, resulting in crystallization. The crystals were suction filtered and dried at 50 ℃ at 0.5 torr. 1.6g of the expected product are obtained.

Mass spectrum (EI): 163.1Th (M/z)⁺)。

Melting point: 195 ℃ and 199 ℃.

Example 5: n- { [1- (dimethylamino) cyclopropyl ] methyl } pyridin-3-amine dihydrochloride

1.26g of the base of the compound of example 4 was dissolved in 25.2ml of formic acid and 25.2ml of 37% formaldehyde. Heated at 70 ℃ for 5 hours. Concentrate to dryness and dissolve the residue in 20ml water and concentrate again. The residue is dissolved in 15ml of 35% sodium hydroxide solution and extracted with ether, and the combined ether phases are sucked dry over sodium sulfate and concentrated to dryness. The residue was chromatographed on 230ml of silica gel (dichloromethane/methanol: 95/5) and 1.17g of residue were obtained dissolved in 25ml of isopropanol. 4M hydrochloric acid in 3ml dioxane was added followed by dilution with 25ml ether. The crystals are filtered off with suction and dried to yield 1.25g of the expected product.

Mass spectrum (ESI): 192.1Th ([ M + H) M/z]⁺)。

Melting point: 208-210 ℃.

Example 6: n- { [1- (benzylamino) cyclopropyl ] methyl } -N-methylpyridine 3-amine

Step 1: benzyl (1- { formyl (pyridin-3-yl) amino } methyl) cyclopropyl) carbamic acid tert-butyl ester

This compound was obtained according to the method of example 2, step 1, replacing the compound in step 1 of example 1 with the compound obtained in preparation 2.

Step 2: n- { [1- (benzylamino) cyclopropyl ] methyl } -N-methylpyridine 3-amine

This compound was obtained according to the method of example 2, step 2, using the compound of step 1 above.

Example 7: n- [ (1-aminocyclopropyl) methyl ] -N-methylpyridin-3-amine dihydrochloride

To a mixture containing 17.7g of the compound of example 6 and 900ml of ethanol was added 5.5ml of 11.8N hydrochloric acid. The mixture was heated to a gentle temperature to obtain a solution. 900ml of cyclohexene were added, followed by 6g of 10% under nitrogen. Reflux for 20 hours, then filter off the catalyst and concentrate the filtrate to dryness. The residue was dissolved in 60ml of 35% sodium hydroxide solution and extracted with copious amounts of ether. The combined ether phases were sucked dry over sodium sulfate and concentrated to dryness. The residue is chromatographed on silica gel (dichloromethane/methanol: 93/7). The base of the desired compound is obtained and converted to a salt by adding a slight excess of hydrochloric acid in ethanol. Diluted with ether. The crystals were suction filtered and dried at 40 ℃ at 1 torr. 2.48g of the expected product are obtained.

Mass spectrum (ESI): m/z 178.1Th ([ M + H)]⁺)。

Melting point: 218 ℃ and 222 ℃.

Example 8: n- { [1- (dimethyl) cyclopropyl ] methyl } -N-methylpyridin-3-amine dihydrochloride

This compound was obtained according to the method of example 5, substituting the compound of example 4 for the compound of example 7.

Mass spectrum (ESI): m/z 206.2Th ([ M + H)]⁺)。

Melting point: 198 ℃ and 201 ℃.

Example 9: 6-chloro-N- { [1- (methylamino) cyclopropyl ] methyl } pyridin-3-amine dihydrochloride

Step 1: (1- { [ (6-Chloropyridin-3-yl) amino ] methyl } cyclopropyl) -methylcarbamic acid tert-butyl ester

To a mixture containing 10.8g of the compound of production method 1, 100ml of methanol and 6.9g of 5-amino-2-chloropyridine, 10ml of acetic acid was added. Stirred at room temperature for 30 minutes. It is cooled to 5 ℃ and 4.4g of sodium cyanoborohydride are added in portions. Stirred for 20 hours at 20 ℃.10 ml of water are added and concentrated to dryness. The residue was dissolved in dichloromethane and aqueous potassium carbonate. Separation was carried out and the aqueous phase was extracted several times with dichloromethane. The combined organic phases were sucked dry over sodium sulfate and concentrated to dryness. Chromatography on silica gel (dichloromethane/tetrahydrofuran: 98/2) gives 9.9g of the expected product.

Step 2: 6-chloro-N- { [1- (methylamino) cyclopropyl ] methyl } pyridin-3-amine dihydrochloride

This compound was obtained according to the method of example 1, step 2, using the compound of step 1 above.

Mass spectrum (ESI): 212.1Th ([ M + H) M/z]⁺)。

Melting point: 196 ℃ and 202 ℃.

Example 10: 6-chloro-N-methyl-N- { [1- (methylamino) cyclopropyl ] } methylpyridin-3-amine dihydrochloride

Step 1: (1- { [ (6-Chloropyridin-3-yl) (formyl) amino ] methyl } cyclopropyl) -methylcarbamic acid tert-butyl ester

This compound was obtained according to the procedure of example 2, step 1, using the compound in example 9, step 1.

Step 2: (1- { [ (6-Chloropyridin-3-yl) (methyl) amino ] methyl } cyclopropyl) -methylcarbamic acid tert-butyl ester

To a mixture containing 3.0g of the compound obtained in step 1 above and 30ml of tetrahydrofuran was poured 2.2ml of 10M borane methyl sulfide complex at 0 ℃. The cooling was stopped and, when the temperature was stabilized, refluxed for 3 hours. After cooling, methanol hydrochloride was added until a pH of 2 was reached. Stirring was carried out at 20 ℃ for 1 hour, followed by refluxing for 1 hour. Concentrate to dryness and dissolve the residue in a mixture of dichloromethane and 4N sodium hydroxide solution. The aqueous phase was separated and extracted with dichloromethane. The combined organic phases were sucked dry over sodium sulfate and concentrated to dryness. The residue is chromatographed on 200g of silica gel (dichloromethane/tetrahydrofuran: 95/5). 1.6g of the expected product are obtained.

And step 3: 6-chloro-N-methyl-N- { [1- (methylamino) cyclopropyl ] } methylpyridin-3-amine dihydrochloride

The product was obtained according to the method of example 1, step 2, using the compound obtained in step 2 above.

Mass spectrum (ESI): 226.1Th ([ M + H) M/z]⁺)。

Melting point: 133 ℃ and 136 ℃.

Example 11: 6-bromo-N- { [1- (methylamino) cyclopropyl ] methyl } pyridin-3-amine fumarate

Step 1: (1- { [ (6-Bromopyridin-3-yl) amino) methyl } cyclopropyl) -methylcarbamic acid tert-butyl ester

The product was obtained according to the procedure of example 9, step 1, using 5-amino-2-bromopyridine instead of 5-amino-2-chloropyridine.

Step 2: 6-bromo-N- { [1- (methylamino) cyclopropyl ] methyl } pyridin-3-amine fumarate

To a mixture containing 2g of the compound obtained in step 1 above and 20ml of dichloromethane was added 3.5ml of trifluoroacetic acid. Stirred at 20 ℃ for 20 hours. A10% aqueous sodium carbonate solution was added until pH > 9. Dichloromethane was added. The organic phase was separated, sucked dry over sodium sulfate and concentrated to dryness. The residue was dissolved in 5ml ethanol. 0.6g fumaric acid dissolved in 10ml ethanol was added. Crystallization was observed. The crystals were suction filtered, washed with ethanol and then ether, and dried at 50 ℃ at 1 torr. 1.6g of the expected product are obtained.

Mass spectrum (ESI): 256.0Th ([ M + H) is defined as M/z]⁺)。

Melting point: 165-169 ℃.

Example 12: 6-bromo-N-methyl-N- { [1- (methylamino) cyclopropyl ] methyl } pyridin-3-amine fumarate

Step 1: (1- { [ (6-Bromopyridin-3-yl) (formyl) amino ] methyl } cyclopropyl) -methylcarbamic acid tert-butyl ester

The product was obtained according to the procedure of example 2 step 1 using the compound of example 11 step 1.

Step 2: (1- { [ (6-Bromopyridin-3-yl) (methyl) amino ] methyl } cyclopropyl) -methylcarbamic acid tert-butyl ester

The product was obtained according to the procedure of example 10 step 2 using the compound of step 1 above.

And step 3: 6-bromo-N-methyl-N- { [1- (methylamino) cyclopropyl ] methyl } pyridin-3-amine fumarate

The product was obtained according to the procedure of example 11, step 2, using the compound obtained in step 2 above.

Mass spectrum (ESI): 270.1Th([M+H]⁺)。

Melting point: 146 ℃ and 150 ℃.

Example 13: 6-methyl-N- { [1- (methylamino) cyclopropyl ] methyl } pyridin-3-amine dihydrochloride

Step 1: (1- { [ 6-methylpyridin-3-yl ] amino } methyl } cyclopropyl) -methylcarbamic acid tert-butyl ester

This compound was obtained according to the procedure of example 9, step 1, using 5-amino-2-methylpyridine instead of 5-amino-2-chloropyridine.

Step 2: 6-methyl N- { [1- (methylamino) cyclopropyl ] methyl } pyridin-3-amine dihydrochloride

This compound was obtained according to the procedure of example 9, step 2, using the product of step 1 above.

Mass spectrum (ESI): 192.2Th ([ M + H) with M/z]⁺)。

Melting point: 230 ℃ and 232 ℃.

Example 14: n, 6-dimethyl-N- { [1- (methylamino) cyclopropyl ] methyl } pyridin-3-amine dihydrochloride

Step 1: (1- { [ formyl (6-methylpyridin-3-yl) amino ] methyl } cyclopropyl) -methylcarbamic acid tert-butyl ester

This compound was obtained according to the procedure of example 2, step 1, using the compound of example 13, step 1.

Step 2: methyl (1- { [ methyl (6-methylpyridin-3-yl) amino ] methyl } cyclopropyl) carbamic acid tert-butyl ester

This compound was obtained according to the procedure of example 2, step 2, using the product of step 1 above.

And step 3: n, 6-dimethyl-N- { [1- (methylamino) cyclopropyl ] methyl } pyridin-3-amine dihydrochloride

This compound was obtained according to the method of example 1, step 2, using the product obtained in step 2 above.

Mass spectrum (ESI): m/z 206.2Th ([ M + H)]⁺)。

Melting point: 112 ℃ and 115 ℃.

Example 15: 6-chloro-N- { [1- (dimethylamino) cyclopropyl ] methyl } pyridin-3-amine dihydrochloride

This compound was obtained using the procedure of example 5, replacing the compound of example 4 with the compound of example 9.

Mass spectrum (EI): 225.1Th (M/z)⁺)。

Melting point: 158 ℃ and 160 ℃.

Example 16: 6-chloro-N- { [1- (dimethylamino) cyclopropyl ] methyl } -N-methylpyridin-3-amine dihydrochloride

Step 1: (6-Chloropyridin-3-yl) ({1- [ formyl (methyl) amino ] cyclopropyl } methyl) carboxamide

1.85ml of formic acid are added to 3.7ml of acetic anhydride at 5 ℃ over a period of 15 minutes, and the mixture is subsequently heated at 55 ℃ for 2 hours. After cooling to room temperature, 7.4ml of tetrahydrofuran were added, and the reaction mixture was cooled to-20 ℃. A solution of 1.57g of the base of the compound of example 9 in 18.5ml of tetrahydrofuran is poured in the course of 30 minutes. The temperature was maintained at-20 ℃ for 1 hour, followed by 0 ℃ for 20 hours. Concentration, the residue was dissolved in 10% aqueous sodium carbonate and extracted with dichloromethane. The dichloromethane was sucked dry over sodium sulfate and concentrated to dryness. Chromatography on silica gel (dichloromethane/methanol: 97.5/2.5) gives 1.73g of the expected product.

Step 2: 6-N- { [1- (dimethylamino) cyclopropyl ] methyl } -N-methylpyridin-3-amine dihydrochloride

1.73g of the compound obtained in step 1 above was dissolved in 48ml of tetrahydrofuran, followed by the addition of 3.6ml of 10M borane methylsulfide complex. Stirred at 20 ℃ for 20 hours and then refluxed for 3 hours. Cooled to 5 ℃ and 6.5ml methanol added; stir for 1 hour and concentrate to dryness. The residue was dissolved in dichloromethane and washed with 10% aqueous sodium bicarbonate. The organic phase is sucked dry over sodium sulfate and concentrated, and the residue is chromatographed on silica gel (dichloromethane/methanol: 97.5/2.5) to give the base of the expected product. 0.7g of base is dissolved in 5ml of isopropanol and an ether solution of hydrochloric acid is added, and 0.85g of the expected product is obtained after filtration and drying of the precipitate.

Mass spectrum (ESI): 240.1Th ([ M + H) M/z]⁺)。

Melting point: 163 ℃ and 166 ℃.

Example 17: N-benzyl-6-chloro-N- { [1- (methylamino) cyclopropyl ] methyl } pyridin-3-amine dihydrochloride

Step 1: (1- { [ benzoyl (6-chloropyridin-3-yl) amino ] methyl } cyclopropyl) -methylcarbamic acid tert-butyl ester

10.17g of the compound obtained in step 1 of example 9 are dissolved in 200ml of tetrahydrofuran, 4.88ml of triethylamine are added, cooling is carried out to 5 ℃ and 5.05g of benzoyl chloride are added over a period of 30 minutes. Stirring was carried out at 5 ℃ for 1 hour, followed by stirring at room temperature for 1 hour, and then refluxing was carried out for 2 hours. Concentrating to dryness. The residue was dissolved in dichloromethane and washed with 50% aqueous potassium carbonate solution. The organic phase is sucked dry over sodium sulfate and concentrated, and the residue is chromatographed on silica gel (dichloromethane/tetrahydrofuran: 96/4) to give 13.9g of the expected product.

Step 2: (1- { [ benzyl (6-chloropyridin-3-yl) amino ] methyl } cyclopropyl) -methylcarbamic acid tert-butyl ester

13.8g of the compound obtained in step 1 above was dissolved in 120ml of tetrahydrofuran, cooled to 5 ℃ and then 8.3ml of 10M borane methylsulfide complex was added. After cooling to room temperature, reflux was carried out for 3 hours. Cooled to 5 ℃ and 15.1ml of methanol are added; stirred for 1 hour and then acidified to pH3 with hydrochloric acid in methanol. Reflux for 1 hour, then concentrate to dryness. The residue was dissolved in dichloromethane and washed with 10% aqueous sodium carbonate solution. The organic phase is sucked dry over sodium sulfate and concentrated, and the residue is chromatographed on silica gel (from dichloromethane to dichloromethane/butanone: 90/10) to yield 6.7g of the expected product.

And step 3: N-benzyl-6-chloro-N- { [1- (methylamino) cyclopropyl ] methyl } pyridin-3-amine dihydrochloride

This compound was obtained according to the method of example 1, step 2, using the compound of step 2 above instead of the compound of example 1, step 1.

Mass spectrum (ESI): m/z 302.1Th ([ M + H)]⁺)。

Melting point: 156 ℃ and 157 ℃.

Example 18: N-benzyl-6-chloro-N- { [1- (dimethylamino) cyclopropyl ] methyl } pyridin-3-amine hydrochloride

3.1g of the base of the compound of example 17 are dissolved in 60ml of formic acid. 60ml of 37% aqueous formaldehyde solution were added and the mixture was heated at 70 ℃ for 4 hours. Concentrating to dryness. The residue was dissolved in 50% aqueous potassium carbonate solution and extracted with dichloromethane. The organic phase is dried over sodium sulfate, concentrated and the residue is chromatographed on silica gel (dichloromethane/acetone: 96/4). A fraction consisting of 0.48g of the base of the expected compound is isolated, and after this fraction has been dissolved in 5ml of ethanol and an ether solution of hydrochloric acid has been added, the precipitate is filtered off and dried to yield 0.4g of the expected product.

Mass spectrum (ESI): 316.16Th ([ M + H) is defined as M/z]⁺)。

Melting point: 190 ℃ and 192 ℃.

Pharmacological study of the Compounds of the invention

Example A: para 2¹²⁵I]-substitution of alpha-bungarotoxin binding to nicotinic receptor in the generator organ of Raja

According to j.pharmacol.exp.ther., 1994, 271; 624-631 this study was carried out in order to assess the affinity of the compounds of the invention for the "muscle" -type nicotinic receptor.

In Krebs buffer (Tris-HCl 50mM, KCl 5mM, MgCl) containing 0.01% BSA₂1mM、CaCl₂2mM, NaCl 100mM, pH 7.4)¹²⁵I](ii) in the presence of-alpha-bungarotoxin (S.A.: 7.4 TBq/mmol: 0.2nM), membrane (1-5. mu.g ^ bamboo ^) of generator organ of Rajaml) were incubated (1 hour, 22 ℃) with a series of concentrations (0.01-10. mu.M) of each compound of the invention (diluted starting from a stock solution in 10mM DMSO); final volume: 500. mu.l. Nonspecific binding was determined by incubating the membranes under alpha-bungarotoxin (1 μ M).

The results show that all compounds of the invention have no significant affinity for the "muscle" -type nicotinic receptor at concentrations up to 10. mu.M (K)_i＞10^-5M)。

Example B: para 2³H]Replacement of epibatidine binding to IMR32 cell nicotinic receptor

According to molec. pharmacol, 1995, 48; 280-287 this study was carried out to determine the affinity of the compounds of the invention for the "ganglionic" nicotinic receptors (American Soc. neuroscience, 2000, 26, 138).

In phosphate buffer (NaH)₂PO₄(±) - [ 2 ], [ pH 7.4) in 20mM³H]-incubating (2 hours, 20 ℃) the membrane of IMR-32 neuroblastoma cells (250. mu.g/ml) with a series of concentrations (0.01-10. mu.M) of each compound of the invention (diluted starting from a stock solution in 10mM DMSO) in the presence of epibatidine (S.A.: 2464 GBq/mmol: 1.5 nM); final volume: 250 μ l. Nonspecific binding was determined by incubating the membrane in the presence of 300 μ M (-) nicotine.

The results show that all compounds of the invention have no significant affinity for the "ganglionic" nicotinic receptors at concentrations up to 10. mu.M (K)_i＞10^-5M)。

Example C: para 2³H]Replacement of oxotremorine-M binding to rat muscarinic brain receptors

This study was carried out according to the method described in Naumyn-Schmiederberg's arch. pharmacol., 2001, 363, 429-.

In phosphate buffer (NaH)₂PO₄20mM, pH 7.4)³H]-incubating (2 hours, 20 ℃) membranes of rat brain (250. mu.g/ml) with a range of concentrations (0.01-10. mu.M) of each compound of the invention (diluted starting from a stock solution in 10mM DMSO) in the presence of oxotremorine-M (S.A.: 3174 GBq/mmol: 2 nM); final volume: 250 μ l. Specific binding was determined by incubating the membrane in the presence of atropine (1 μ M). The affinity of the compounds of the invention for muscarinic receptors is determined by determining K_iAnd (5) characterizing.

The results show that all compounds of the invention have no affinity for the "muscarinic" receptor at concentrations up to 10 μ M (K)_i＞10^-5M)。

Example D: para 2¹²⁵I]Replacement of alpha-bungarotoxin binding to the nicotinic receptor of the "alpha 7 type" of the rat brain

According to molec pharmacol, 1986, 30; 427-436, in order to determine the affinity of the compounds of the invention for the α 7 central nicotinic receptor.

In Krebs buffer (Tris-HCl 50mM, KCl 5mM, MgCl) containing 0.05% BSA₂1mM、CaCl₂2mM, NaCl 100mM, pH 7.4)¹²⁵I]-incubating (5 hours, 37 ℃) membranes of rat brain (1000. mu.g/ml) with a series of concentrations (0.01-10. mu.M) of each compound of the invention (diluted starting from a stock solution in 10mM DMSO) in the presence of α -bungarotoxin (S.A.: 7.4 TBq/mmol: 1 nM); final volume: 500. mu.l. Nonspecific binding was determined by incubating the membranes in the presence of alpha-bungarotoxin (1. mu.M). The affinity of the compounds of the invention for the alpha 7 nicotinic receptor was determined by determining K_iAnd (5) characterizing.

The results show that all compounds of the invention have no affinity for the central nicotinic receptor type alpha 7 at concentrations up to 10. mu.M (K)_i＞10^-5M). Certain compounds of the invention have a K on the order of 10. mu.M_iExample 2 Compounds, K_iIs 8.0X 10^-6M。

Example E: para 2³H]-cytisine bindingReplacement of alpha 4 beta 2 nicotinic receptor of rat brain

According to molec pharmacol, 1990, 39; 9-12, the present study was conducted to determine the affinity of the compounds of the invention for the α 4 β 2 type central nicotinic receptor.

In phosphate buffer (NaH)₂PO₄20mM, pH 7.4)³H]-incubating (2 hours, 20 ℃) membranes of rat brain (250. mu.g/ml) with a series of concentrations (0.01-10. mu.M) of each compound of the invention (diluted starting from a stock solution in 10mM DMSO) in the presence of cytisine (S.A.: 1184 GBq/mmol: 2 nM); final volume: 250 μ l. Nonspecific binding was determined by incubating the membrane in the presence of 10 μ M (-) nicotine. The affinity of the compounds of the invention for the central nicotinic receptor type alpha 4 beta 2 is determined by determining K_iAnd (5) characterizing.

The results obtained show that the compounds of the invention show a strong affinity for the central nicotinic receptor type α 4 β 2. And K of the Compounds of examples 1, 2 and 10_iValues were 3.4X 10, respectively^-8M、1.5×10^-8M and 1.64X 10^-8M。

These results, as well as the results obtained in examples a to D, indicate that the compounds of the invention are potent central nicotinic ligands specific for the α 4 β 2 type receptor.

Example F: in vivo measurement of acetylcholine release by performing intradermal microdialysis in conscious Wistar rats

In vivo experiments, systemic administration of nicotine and nicotinic agonists results in increased acetylcholine in various regions of the brain (neurohem. Res., 1996, 21, 1118-. Microdialysis probes were implanted in the central prefrontal cortex of male Wistar rats. 6 days or 7 days after the implantation of the probe, Ringer's solution (NaCl 147mM, KCl 2.7mM, CaCl) was perfused at a flow rate of 1. mu.l/min₂1.2mM、MgCl₂1mM, 2nM neostigmine), the animals were allowed to move freely. After 2 hoursOne quarter of the animals were administered the product to be tested by intraperitoneal route. One group of control animals received the solvent for the product. The dialysate (30 μ l) was collected every 30 minutes for 4 hours to measure the concentration of acetylcholine outside the cortical synapses by HPLC equipped with amperometric detection. Results are expressed as pg acetylcholine/dialysate and comparisons between groups were made with two-factor (treatment x time) analysis of variance and measurements repeated over time.

The results obtained show that the compounds of the invention increase acetylcholine release from the cortex in vivo in a dose-dependent manner, ranging from 0.3 to 3mg/kg IP, indicating that the compounds of the invention are characterized as α 4 β 2 agonists. Thus, the compounds of examples 1 and 2 induced a 70% and 86% increase in acetylcholine release in the prefrontal cortex of awake Wistar rats, respectively, after 1 hour of administration at a dose of 3mg/kg IP.

Example G: abdominal contraction induced by phenyl-p-benzoquinone (PBQ) in NMRAI mice

In mice, intraperitoneal administration of PBQ alcoholic solution caused abdominal cramping (proc. soc. exp. biol., 1957, 95, 729-. This spasm is characterized by repeated contractions of the abdominal musculature, accompanied by hindlimb extension. Most analgesics are resistant to such abdominal cramps (brit.j.pharmacol.chem., 1968, 32, 295-310). At t-0 min, animals were weighed and the compound studied was administered by IP route. The group of control animals was given the solvent for the compound. PBQ alcoholic solution (0.2%) was administered by IP route at a volume of 0.25 ml/mouse at t-30 min. Immediately after PBQ administration, animals were placed in plexiglass jars (L ═ 19.5 cm; i.d. ═ 5 cm). From t 35 minutes to t 45 minutes, animal responses were observed and the experimenter recorded the total number of abdominal cramps per animal. The results are expressed as a percentage of inhibition of the number of abdominal cramps in the control animals tested at the active dose of the compound studied.

The results obtained show an inhibition of 80% for an active dose of 10mg/kg IP, which indicates that the compounds of the invention have analgesic properties. The compounds of examples 1, 2, 9 and 10, when administered at a dose of 10mg/kgIP, reduced the number of abdominal cramps in mice caused by PBQ administration by 50%, 76%, 52% and 69%, respectively.

Example H: social identification of Wistar rats

The social recognition test described initially in 1982 (J.Comp.Physiol., 1982, 96, 1000-S.1006) has since been suggested by various authors (Psychopharmacology, 1987, 91, 363-S.368; Psychopharmacology, 1989, 97, 262-S.268) for studying the memory cognitive effects of novel compounds. The test is based on the natural expression of olfactory memory in rats and their natural tendency to forget, and memory is assessed by the recognition of young rats of the same kind by adult rats. A randomly selected young rat (21 days old) was placed in a cage into which an adult rat had been placed for 5 minutes. With the aid of a video device, the laboratory investigator observed the socially recognized behavior of the adult rat and measured the entire duration. The young rat is then removed from the adult rat cage and placed in the young rat's own cage until the second encounter. The compound to be tested is then administered to the adult rat by the intraperitoneal route, and after 2 hours, the adult rat is again subjected to the juvenile rat (5 minutes). The social recognition behavior is then observed again and its duration measured. The evaluation criterion was the difference in the "recognition" times at the two encounters (T2-T1), expressed in seconds.

The results show that for the 1 to 3mg/kg IP dose range, the difference (T2-T1) is-19 seconds to-36 seconds, indicating that the compounds of the invention greatly enhance memory, even at low doses. Thus, the compounds of examples 1, 2 and 4 caused differences of 36 seconds, 29 seconds and 19 seconds at the 3mg/kg IP dose, respectively (T2-T1).

Example I: object recognition in Wistar rats

The object recognition test in Wistar rats (behav. brain res., 1988, 31, 47-59) is based on the natural exploratory activity of animals and has human paroxysmal memory characteristics. Since it is sensitive to aging (eur.j. pharmacol., 1997, 325, 173-180) and cholinergic dysfunction (pharm.biochem.behav., 1986, 53(2), 277-283), this test is based on the differential exploration of 2 objects of fairly similar size, one of which is familiar and the other of which is new. Prior to testing, animals had acclimated to the environment (hood without objects). In the first phase, rats are placed in a hood containing two identical objects (3 minutes). The duration of the rat exploration for each object was measured. In a second phase (3 minutes) after 24 hours, one of the two objects is replaced with a new one. The duration of exploring each object is measured. The evaluation criterion is the difference Δ in seconds between the exploration time for the new object and for the familiar object in the second phase. Control animals, which were previously treated with vehicle orally 60 minutes prior to each stage, explored familiar and new objects in the same manner, indicating that they had forgotten what had happened to be. Animals treated with memory recognition-promoting compounds preferentially explore new objects, indicating that an object that has emerged has been remembered.

The results obtained show that there is a difference Δ at the level of 9 seconds for the PO dose range from 0.01 to 0.3mg/kg, indicating that the compounds of the invention greatly enhance memory, even at very low doses. Thus, the compounds of examples 1 and 2, when administered at a dose of 0.3mg/kgPO, caused a difference Δ of 9 seconds and 4 seconds, respectively.

Example J: pharmaceutical composition of 1000 tablets each containing 10mg of active ingredient

10g

10g

.

.

.

Claims (11)

1. A compound of formula (I) or a pharmaceutically acceptable acid or base addition salt thereof:

wherein:

n represents an integer of from 1 to 6 inclusive,

R₁and R₂May be identical or different and independently of one another represent a hydrogen atom, a linear or branched chain (C)₁-C₆) The alkyl or alkyl moiety may be a straight or branched chain aryl- (C)₁-C₆) An alkyl group, a carboxyl group,

R₃and R₄May be identical or different and independently of one another represent a hydrogen atom or a linear or branched (C)₁-C₆) An alkyl group, a carboxyl group,

R₅and R₆May be identical or different and independently of one another represent a hydrogen atom or a linear or branched (C)₁-C₆) Alkyl, halogen, hydroxy, straight or branched chain (C)₁-C₆) Alkoxy, cyano, nitro, straight or branched chain (C)₂-C₆) Acyl, straight or branched (C)₁-C₆) Alkoxycarbonyl, straight-chain or branched (C)₁-C₆) Trihaloalkyl or straight or branched chain (C)₁-C₆) Trihaloalkoxy or optionally substituted by one or two straight or branched chains (C)₁-C₆) An amino group substituted with an alkyl group,

R₇represents a hydrogen atom, a straight chain or a branched chain (C)₁-C₆) The alkyl or alkyl moiety may be a straight or branched chain aryl- (C)₁-C₆) An alkyl group.

Aryl is understood to be phenyl, biphenyl, naphthyl, dihydronaphthyl, tetrahydronaphthyl, 1, 3 indanyl or indenyl, each of which may optionally be substituted by one or more identical or different groups selected from: halogen atom, straight or branched chain (C)₁-C₆) Alkyl, hydroxy, cyano, nitro, straight or branched chain (C)₁-C₆) Alkoxy, straight or branched chain (C)₂-C₇) Acyl, straight or branched (C)₁-C₆) Alkoxycarbonyl, straight-chain or branched (C)₁-C₆) Trihaloalkyl and straight or branched chain (C)₁-C₆) Trihaloalkoxy and optionally one or two straight or branched chains (C)₁-C₆) Amino substituted by alkyl.

2. A compound of formula (I), or a pharmaceutically acceptable acid or base addition salt thereof, according to claim 1, wherein said compound of formula (I) is characterized by the integer value of 1.

3. The compound of formula (I), or a pharmaceutically acceptable acid or base addition salt thereof, according to claim 1, wherein said compound of formula (I) is characterized by R₁And R₂May be identical or different and independently of one another represent a hydrogen atom or a linear or branched (C)₁-C₆) An alkyl group.

4. The compound of formula (I), or a pharmaceutically acceptable acid or base addition salt thereof, according to claim 1, wherein said compound of formula (I) is characterized by R₃And R₄Represents a hydrogen atom.

5. The compound of formula (I), or a pharmaceutically acceptable acid or base addition salt thereof, according to claim 1, wherein said compound of formula (I) is characterized by R₅And R₆May be identical or different and independently of one another represent a hydrogen atom or a linear or branched (C)₁-C₆) An alkyl group.

6. The compound of formula (I), or a pharmaceutically acceptable acid or base addition salt thereof, according to claim 1, wherein said compound of formula (I) is characterized by R₇Represents a hydrogen atom or a linear or branched chain (C)₁-C₆) An alkyl group.

7. A compound of formula (I), or a pharmaceutically acceptable acid or base addition salt thereof, as claimed in claim 1, wherein said compound of formula (I) is:

n- { [1- (methylamino) cyclopropyl ] methyl } pyridin-3-amine,

N-methyl-N- { [1- (methylamino) cyclopropyl ] methyl } pyridin-3-amine,

n- [ (1-aminocyclopropyl) methyl ] pyridin-3-amine,

n- { [1- (dimethylamino) cyclopropyl ] methyl } pyridin-3-amine,

n- [ (1-aminocyclopropyl) methyl ] -N-methylpyridin-3-amine,

n- { [1- (dimethylamino) cyclopropyl ] methyl } -N-methylpyridin-3-amine,

6-chloro-N- { [1- (methylamino) cyclopropyl ] methyl } pyridin-3-amine,

6-chloro-N-methyl-N- { [1- (methylamino) cyclopropyl ] methyl } pyridin-3-amine,

6-bromo-N- { [1- (methylamino) cyclopropyl ] methyl } pyridin-3-amine,

6-bromo-N-methyl-N- { [1- (methylamino) cyclopropyl ] methyl } pyridin-3-amine,

6-methyl-N- { [1- (methylamino) cyclopropyl ] methyl } pyridin-3-amine,

n, 6-dimethyl-N- { [1- (methylamino) cyclopropyl ] methyl } pyridin-3-amine.

8. A pharmaceutical composition comprising as active ingredient at least one compound according to any one of claims 1 to 7, alone or in combination with one or more pharmaceutically acceptable inert non-toxic excipients or carriers.

9. Pharmaceutical composition according to claim 8, comprising at least one active ingredient according to any one of claims 1 to 7, wherein said active ingredient acts as a specific nicotinic ligand of the α 4 β 2 receptor.

10. The pharmaceutical composition according to claim 8, comprising at least one active ingredient according to any one of claims 1 to 7, wherein said pharmaceutical composition is used for the treatment of memory impairment associated with brain aging and neurodegenerative diseases and for the treatment of mood disorders, Tourette's syndrome, attention deficit hyperactivity disorder, tobacco withdrawal and pain.

11. The pharmaceutical composition according to claim 8, comprising at least one active ingredient according to any one of claims 1 to 7, wherein said pharmaceutical composition is used for the treatment of memory impairment associated with alzheimer's disease, parkinson's disease, pick's disease, korsakoff's psychosis or frontal lobe and subcortical dementia.