WO2020193448A1

WO2020193448A1 - Multitarget compounds for the treatment of alzheimer's disease

Info

Publication number: WO2020193448A1
Application number: PCT/EP2020/057914
Authority: WO
Inventors: Diego MUÑOZ-TORRERO LÓPEZ-IBARRA; Santiago VÁZQUEZ CRUZ; Caterina PONT MASANET; Sandra CODONY GISBERT
Original assignee: Universitat De Barcelona
Priority date: 2019-03-28
Filing date: 2020-03-23
Publication date: 2020-10-01

Abstract

The invention provides compounds of formula I wherein: m is 0, 1 or 2; n is 2, 3, 4 or 5; R₀and R₁ are both H, or they form a bridge -CH₂-C(R₄ )=CH-, R₄being CH₃ or CH₂CH₃; R₂ and R₃ independently are H, F, Cl or (C₁-C₄)-alkyl; R₅ is H, F, Cl, Br, I, OCH₃, OCF₃, SF₅, SO₂F, SO₂CH₃, NO₂, CF₃ or (C₁-C₄)-alkyl; R₆ and R₇ independently are H, F, Cl, CH₃ or CF₃; and optionally R₅ and R₆ form a bridge -O-CH₂ -O-, R₇ being H, in vitro assays show that compounds I are simultaneously inhibitors of acetylcholinesterase and inhibitors of soluble epoxide hydrolase, and that they have a good blood-brain barrier permeability. Thus, compounds I are multitarget active pharmaceutical ingredients for the treatment of Alzheimer's disease in humans.

Description

Multitarget compounds for the treatment of Alzheimer’s disease

TECHNICAL FIELD

The present invention relates to human therapy, particularly to the field of small-molecule compounds for multitarget therapy of Alzheimer’s disease (AD).

BACKGROUND ART

AD is a progressive neurodegenerative disorder that inevitably leads to the death of the patient after years of decline of cognitive and functional abilities, which causes immense suffering to patients and caregivers. AD is the most common cause of dementia and the most prevalent neurodegenerative disorder. The devastating effects of AD can be ascribed, at least in part, to the lack of drugs that can prevent or arrest the progression of the disease.

Multitarget therapies have been tried to find new drugs to treat AD (cf. D. Munoz-Torrero, "Multitarget Anti-Alzheimer Hybrid Compounds: Do They Work In Vivo?"; in M. Decker (ed.), "Design of Hybrid Molecules for Drug Development"; Elsevier, 2017, pp.167-192; ISBN 978-0-08-101011-2; https://doi.org/10.1016/B978-0-08-101011-2.00006-4; and M. de Reitas Silva et al. , "Multi-Target Directed Drugs as a Modern Approach for Drug Design Towards Alzheimer’s Disease: An Update", Curr. Med. Chem., 2018, vol. 25, pp. 3491-3525; doi: 10.2174/0929867325666180111101843).

The most classical strategies of multitarget therapies involve the use of several drugs either separately (drug cocktails) or formulated jointly into a single medicine (fixed-dose combinations). These modalities suffer from a number of important shortcomings that are inherent to the use of two or more distinct medicines and/or drugs, prominently patient compliance issues and high likelihood of drug-drug interactions. These limitations are overcome with the use of a single-molecule endowed with the adequate potency against several biological targets, the so-called multitarget drugs or multitarget-directed ligands. Multitarget drugs would also benefit from the rest of the features associated with the development of any single-molecule drug, such as more predictable pharmacokinetics and pharmacodynamics and easier clinical development, manufacturing, or intellectual property issues, among others.

The AD drug discovery arena is one of the fields where the development of multitarget therapies has been most vigorously pursued in the past decade. The combination of two or more distinct pharmacophoric moieties in a single hybrid molecule represents the most usual way to build multitarget anti-Alzheimer drug candidates. Using this approach, a plethora of structural classes has been rationally designed, synthesized, and tested in vitro against the planned biological targets and, often, screened against additional proteins or pathological events of interest, but very often they do not display well balanced potencies against their different targets, desirable for clinical use. Indeed, no rationally designed multitarget compound has been approved so far for treatment of AD.

SUMMARY OF INVENTION Inventors have found that novel compounds are useful as multitarget active

pharmaceutical ingredients (API) for the treatment of AD, as they are simultaneously inhibitors of acetylcholinesterase (AChE) and inhibitors of soluble epoxide hydrolase (sEH), and they have a good permeability for blood-brain barrier (BBB). AChE is a well-established target for the treatment of AD, as illustrated by the fact that four out of the five API which have been approved by the Food and Drug Administration for the treatment of AD symptoms are AChE inhibitors, namely: donepezil, tacrine, rivastigmine and galantamine (cf. e.g. H. Wang et al. , "Reconsideration of

Anticholinesterase Therapeutic Strategies against Alzheimer’s Disease", ACS Chem. Neurosci. 2019, vol. 10, pp. 852-862; doi: 10.1021/acschemneuro.8b00391). sEH is a target for the treatment of AD that has been recently discovered by inventors (cf. C. Galdeano et al., "Soluble Epoxide Hydrolase Inhibition as a New Therapeutic Strategy for the Treatment of Alzheimer’s Disease", XXV EFMC International Symposium on Medicinal Chemistry; Ljubljana, Slovenia; Sept. 2-6, 2018; poster and abstract num. 335).

An aspect of the present invention refers to the provision of compounds of formula I and their pharmaceutically acceptable salts, wherein:

m is 0, 1 or 2;

n is 2, 3, 4 or 5;

are both H, or they form a bridge -CH₂-C(R₄ )=CH- wherein R₄ is CH₃ or CH2CH3 ;

R₂ and R₃ are radicals independently selected from the group consisting of: H, F, Cl and (C C₄)-alkyl;

R₅ is a radical selected from the group consisting of: H, F, Cl, Br, I, OCH₃ , OCF₃ , SF₅ , S0₂F , S0₂CH₃ , N0₂ , CF₃ , and (C C₄)-alkyl;

R₆ and Ry are radicals independently selected from the group consisting of: H, F, Cl, CH₃ and CF₃ ; and

optionally R₅ and R₆ form a bridge -0-CH₂ -O- , R₇ being H. In particular embodiments of compounds of formula I, m is 1. In other particular embodiments, R₃ is H. In other particular embodiments, R₂ is Cl. In other particular embodiments R₆ is H or F, and R₇ is H. In other particular embodiments R₅ is OCF₃ , F , or S0₂CH₃ . In other particular embodiments R₀ and R^ are both H. In other particular embodiments R₀ and R^ form a bridge -CH₂-C(R₄ )=CH-, and the two carbon atoms where the bridge is attached have configurations which are either (R,R) or (S,S). The present invention relates to all possible combinations of particular embodiments described herein.

Other particular embodiments of compounds of formula I are the following nine compounds, whose preparations are disclosed in the accompanying examples:

1-{1-{3-[(6-chloro-1 ,2,3,4-tetrahydroacridin-9-yl)amino]propanoyl}piperidin-4-yl}-3-[4- (trifluoromethoxy)phenyl]urea, la;

1-{1-{4-[(6-chloro-1 ,2,3,4-tetrahydroacridin-9-yl)amino]butanoyl}piperidin-4-yl}-3-[4- (trifluoromethoxy)phenyl]urea, lb;

1-{1-{5-[(6-chloro-1 ,2,3,4-tetrahydroacridin-9-yl)amino]pentanoyl}piperidin-4-yl}-3-[4- (trifluoromethoxy)phenyl]urea, lc;

(-M7S, 1 1 S)-1 -{1 -{5-[(3-chloro-6,7, 10,1 1 -tetrahydro-9-methyl-7, 1 1 - methanocycloocta[Jb]quinolin-12-yl)amino]pentanoyl}piperidin-4-yl}-3-[4- (trifluoromethoxy)phenyl]urea, Id;

(+)-(7 R, 1 1 R)-1 -{1 -{5-[(3-chloro-6,7, 10, 11 -tetrahydro-9-methyl-7, 1 1 - methanocycloocta[Jb]quinolin-12-yl)amino]pentanoyl}piperidin-4-yl}-3-[4- (trifluoromethoxy)phenyl]urea, le;

1-{1-{5-[(6-chloro-1 ,2,3,4-tetrahydroacridin-9-yl)amino]pentanoyl}piperidin-4-yl}-3-(3,4- difluorophenyl)urea, If;

1-{1-{5-[(6-chloro-1 ,2,3,4-tetrahydroacridin-9-yl)amino]pentanoyl}piperidin-4-yl}-3-[3- fluoro-4-(trifluoromethoxy)phenyl]urea, Ig; 1-[benzo[<¾[1 ,3]dioxol-5-yl]-3-{1-{5-[(6-chloro-1 ,2,3,4-tetrahydroacridin-9- yl)amino]pentanoyl}piperidin-4-yl}urea, Ih; and

1-{1-{5-[(6-chloro-1 ,2,3,4-tetrahydroacridin-9-yl)amino]pentanoyl}piperidin-4-yl}-3-[4- (methylsulfonyl)phenyl]urea, li.

As illustrated by the results of the in vitro assays of accompanying examples, compounds I of the present invention or their pharmaceutically acceptable salts are simultaneously inhibitors of AChE (cf. Example 16) and inhibitors of sEH (cf. Example 15); besides, they have good BBB permeability (cf. Example 17). Thus, compounds I or their salts are useful as multitarget compounds for the treatment of AD.

Other aspect of the present invention refers to pharmaceutical compositions comprising effective amounts of compounds of formula I or their pharmaceutically acceptable salts, together with adequate amounts of pharmaceutically acceptable excipients or carriers.

Other aspect of the present invention refers to compounds of formula I or their

pharmaceutically acceptable salts, for use as active pharmaceutical ingredients.

Other aspect of the present invention refers to compounds of formula I or their

pharmaceutically acceptable salts, for use as active pharmaceutical ingredients in the treatment of AD. In other words, the invention relates to the use of compounds of formula I or their pharmaceutically acceptable salts in the manufacture of a medicament for the treatment of AD. It also may be said that the invention relates to a method of treatment of a human having AD, comprising the administration of an effective amount of a compound of formula I or a pharmaceutically acceptable salt thereof.

Compounds of formula I can be prepared by a process which comprises reacting corresponding carboxylic acids of formula II, or their salts or their reactive derivatives, with substituted ureas of formula III or their salts. If desired, compounds of formula I thus obtained can be converted into their pharmaceutically acceptable salts by reacting with corresponding pharmaceutically acceptable acids.

Reactive derivatives of a carboxylic acid of formula II may be e.g. acyl halides, anhydrides, or activated esters thereof. Thus, a carboxylic acid II can be converted into an acyl halide thereof, such as the acid chloride, by treatment with the corresponding thionyl halide, such as thionyl chloride; and a carboxylic acid II can also be converted into an anhydride thereof, including a mixed anhydride, or into an activated ester thereof, by methods well known in the art. Substituted ureas of formula III are either known, or they are obtainable from known starting materials by methods well known in the art. Carboxylic acids of formula II can be prepared by subjecting corresponding nitriles of formula IV or their salts to a hydrolysis reaction, using acidic or basic conditions.

Nitriles of formula IV or their salts can be prepared by reacting corresponding amines of formula V or their salts with halonitriles of formula X-(CH₂)_n-CN, wherein: n is 2, 3, 4 or 5; and X is a halogen, preferably Cl, Br or I, more preferably Br. Alternatively, nitriles of formula IV or their salts can be prepared by reacting NaCN with corresponding halides of formula VI, wherein: n is 2, 3, 4 or 5; and X is a halogen or an alkylsulphonate or arylsulphonate. These two alternative preparation processes are illustrated in

accompanying Examples 1-5.

V VI Halides of formula VI can be prepared by reacting corresponding alcohols of formula VII with alkylsulphonyl or arylsulphonyl chlorides, or with halogenating agents such as hydrogen halides, phosphorus halides, or phosphorus oxyhalides, by processes well known in the art. Alcohols of formula VII can be prepared by reacting corresponding intermediates of formula VIII with HO-(CH₂)_n-NH₂ by processes well known in the art.

Throughout the description and claims the word "comprise" and variations of the word, are not intended to exclude other technical features, additives, components, or steps. Furthermore, the word "comprise" encompasses the case of "consisting of". Additional objects, advantages and features of the invention will become apparent to those skilled in the art upon examination of the description or may be learned by practice of the invention. The following examples are provided by way of illustration, and they are not intended to be limiting of the present invention. Furthermore, the present invention covers all possible combinations of particular embodiments described herein.

DESCRIPTION OF EMBODIMENTS

Melting points were determined in open capillary tubes with a MFB 595010M Gallenkamp melting point apparatus. High resolution mass spectra were carried out at the Centres Cientifics i Tecnologics of the University of Barcelona with a LC/MSD TOF Agilent Technologies spectrometer. IR spectra were run on a Perkin-Elmer Spectrum RX I spectrophotometer. Absorption values are expressed as wave-numbers (cm ¹); only significant absorption bands are given. Column chromatography was performed on silica gel 60 AC.C (40-60 mesh, SDS, ref 2000027). Thin-layer chromatography was performed with aluminum-backed sheets with silica gel 60 F254 (Merck, ref 1.05554), and spots were visualized with UV light and 1 % aqueous solution of KMn0₄. Analytical grade solvents were used for crystallization, while pure for synthesis solvents were used in the reactions, extractions and column chromatography. Example 1 : Preparation of 3-r(6-chloro-1 ,2,3,4-tetrahydroacridin-9-yl)amino1- propanenitrile, IVa (nitrile of formula IV wherein: n = 2; R₀ = = R₃ = H; R₂ = Cl).

To a solution of 2-[(6-chloro-1 ,2,3,4-tetrahydroacridin-9-yl)amino]ethyl methanesulfonate (383 mg, 1.08 mmol) in dry DMF (3 ml_), NaCN (53 mg, 1.08 mmol) was added. The reaction mixture was stirred at 35 °C for 2 h. The resulting mixture was treated with H₂0 (4 ml_) and 1 N NaOH (6 ml_), and was extracted with EtOAc (3 x 5 ml_). The combined organic extracts were washed with H₂0 (3 x 5 ml_) and brine (5 ml_), dried over anhydrous Na₂S0₄, filtered and evaporated under reduced pressure to give a crude product (348 mg), which was subjected to column chromatography [40-60 pm silica gel (17.5 g), hexane/EtOAc/Et₃N mixtures, gradient elution]. On elution with

hexane/EtOAc/Et₃N 86:14:0.2 to 75:25:0.5, the compound of the title (157 mg, 51% yield) was isolated as a yellowish oil. The isolated compound IVa of the title was transformed into the corresponding hydrochloride as follows: A solution of the free base (28 mg) in CH₂CI₂ (2 ml_) was filtered through a 0.2 pm PTFE filter and treated with excess of a solution of HCI in Et₂0. The solution was concentrated in vacuo to dryness and the solid residue was washed with hexane (3 x 2 ml_) and pentane (3 x 2 ml_) and was dried at 45 °C/2 Torr for 7 days to give IVa_*HCI (29 mg) as a yellowish solid. Characterization: IVa: R_f = 0.3 (hexane/EtOAc/50% aq. NH₄OH 6:4:0.02). IVa*HCI: mp 278 °C (dec); IR (ATR) v: 3500-2500 (max at 3226, 2943, 2727, N-H,⁺N-H, and C-H st), 2248 (CN st),1639, 1610, 1568, 1534 (ar-C-C and ar-C-N st) crrf¹; HRMS (ESI) calcd for (C₁₆H₁₆ ³⁵CIN₃ + H⁺) 286.1106, found 286.1101.

Example 2: Preparation of 4-r(6-chloro-1 ,2,3,4-tetrahydroacridin-9-yl)amino1butanenitrile, IVb (nitrile of formula IV wherein: n = 3; R₀ = Ri = R₃ = H; R₂ = Cl)

It was prepared in an analogous manner to the one described for the compound of Example 1. From 3-[(6-chloro-1 ,2,3,4-tetrahydroacridin-9-yl)amino]propyl

methanesulfonate (539 mg, 1.46 mmol) and NaCN (358 mg, 7.30 mmol), the title compound IVb (400 mg, 91 % yield) was obtained as a brown oil. This compound was transformed into the corresponding hydrochloride as follows: A solution of the free base (39 mg) in CH₂CI₂ (2 ml_) was filtered through a 0.2 pm PTFE filter and treated with excess of a solution of HCI in Et₂0. The solution was concentrated in vacuo to dryness and the solid was washed with hexane (3 x 2 ml_) and pentane (3 x 2 ml_) and was dried at 45 °C/2 Torr for 7 days to give IVb_*HCI (41 mg) as a yellowish solid. Characterization: IVb: R_f = 0.3 (hexane/EtOAc/50% aq. NH₄OH 6:4:0.02). IVb*HCI: mp 201 °C (dec); IR (ATR) v: 3500-2500 (max at 3050, 2930, 2861 , N-H,⁺N-H, and C-H st), 2232 (CN st), 1629, 1567, 1514 (ar-C-C and ar-C-N st) crrf¹; HRMS (ESI) calcd for (C₁₇H₁₈ ³⁵CIN₃ +

H⁺) 300.1262, found 300.1260. Example 3: Preparation of 5-r(6-chloro-1 ,2,3,4-tetrahydroacridin-9-yl)aminolpentanenitrile,

IVc (nitrile of formula IV wherein: n = 4; R₀ = Ri = R₃ = H; R₂ = Cl) A well stirred suspension of 6-chlorotacrine hydrochloride (300 mg, 1.11 mmol) and finely powdered KOH (85% purity reagent, 281 mg, 4.26 mmol) in anhydrous DMSO (4 ml_) was heated every 10 min approximately with a heat gun for 1 h and at room temperature for one additional hour, and then a solution of 5-bromopentanenitrile (0.17 ml_, 230 mg, 1.42 mmol) in DMSO (1 ml_) was added. The reaction mixture was stirred at room temperature overnight, diluted with aqueous 5 N NaOH (30 ml_) and extracted with EtOAc (3 x 20 ml_). The combined organic extracts were washed with water (3 x 30 ml_) and brine (30 ml_), dried with anhydrous Na₂S0₄, filtered and evaporated under reduced pressure to give a residue (419 mg), which was subjected to a recrystallization from EtOAc (2.5 ml_), to afford a white solid consisting of unreacted 6-chlorotacrine, with the mother liquors being enriched in the desired nitrile IVc. After evaporation of the mother liquors at reduced pressure, this recrystallization process was repeated twice (EtOAc, 2 x 1 ml_). Evaporation of the final mother liquors afforded pure nitrile IVc (289 mg, 83% yield) as a yellow oil. The isolated compound of the title was transformed into the corresponding hydrochloride as follows: A solution of the free base (21 mg) in CH₂CI₂ (1 ml_) was filtered through a 0.2 pm PTFE filter and treated with excess of methanolic solution of HCI. The solution was concentrated in vacuo to dryness and the solid residue was washed with pentane (3 x 2 ml_) and was dried at 45 °C/2 Torr for 7 days to give IVc'HCI (25 mg) as a yellowish solid. Characterization: IVc: R_f = 0.73 (CH₂CI₂/MeOH/50% aq. NH₄OH 95:5:1). IVc*HCI: mp 73-75 °C; IR (ATR) v: 3500-2500 (max at 3126, 3043, 2920, 2857, N-H,⁺N-H, and C-H st), 2236 (CN st), 1631 , 1573, 1515 (ar-C-C and ar-C-

N st) cm ¹; HRMS (ESI) calcd for (C₁₈H₂o³⁵CIN₃ + H⁺) 314.1419, found 314.1416.

Example 4: Preparation of (-)-(7S,11 S)-5-r(3-chloro-6,7,10,11-tetrahvdro-9-methyl-7,11- methanocvclooctarb1quinolin-12-yl)aminolpentanenitrile, IVd (nitrile of formula IV with (S,S) configurations, wherein: n = 4; R₀ and form a bridge -CH₂-C(R₄ )=CH- with R₄ =

CH₃; R₃ = H; R₂ = Cl)

It was prepared in an analogous manner to the one described for the compound of Example 3. From (7S,11 S)-12-amino-3-chloro-6,7,10,11-tetrahydro-9-methyl-7,11- methanocycloocta[Jb]quinoline (297 mg, 1.04 mmol) and 5-bromopentanenitrile (0.16 ml_, 227 mg, 1.40 mmol), a crude product (349 mg) was obtained and subjected to column chromatography [40-60 pm silica gel (17 g), hexane/CH₂CI₂/Et₃N mixtures, gradient elution]. On elution with hexane/CH₂CI₂/Et₃N 86:14:0.4, impure nitrile IVd (250 mg) was obtained. After two consecutive recrystallizations from EtOAc (2 ml_ + 1 ml_), the compound IVd of the title (206 g, 54% yield) was isolated from the mother liquors as a yellowish oil. Characterization: IVd: R_f = 0.62 (hexane/CH₂CI₂/50% aq. NH₄OH 6:4:0.04); [a]²⁰o = -95 (c = 0.48, CH₂CI₂); IR (ATR) V: 3377 (N-H st), 2242 (CN st), 1654, 1607,

1577, 1556 (ar-C-C and ar-C-N st) crrf¹ ; HRMS (ESI) calcd for (C₂₂H₂₄ ³⁵CIN₃ + H⁺) 366.1732, found 366.1734.

Example 5: Preparation of (+)-(7f?, 11 f?)-5-r(3-chloro-6,7, 10,1 1-tetrahvdro-9-methyl-7,1 1- methanocvclooctar£>1quinolin-12-yl)aminolpentanenitrile, IVe (nitrile of formula IV with (R,R) configurations, wherein: n = 4; R₀ and form a bridge -CH₂-C(R₄ )=CH- with R₄ = CH₃; Rs = H; R₂ = Cl)

It was prepared in an analogous manner to the one described for the compound of Example 3. From (7R, 11 R)-12-amino-3-chloro-6,7, 10,1 1-tetrahydro-9-methyl-7, 11- methanocycloocta[Jb]quinoline (250 mg, 0.88 mmol) and 5-bromopentanenitrile (0.1 1 ml_, 156 mg, 0.96 mmol), a crude product (309 mg) was obtained and subjected to column chromatography [40-60 pm silica gel (17 g), hexane/CH₂CI₂/Et₃N mixtures, gradient elution]. On elution with hexane/CH₂CI₂/Et₃N 100:0:0.4 to 98:2:0.4, impure nitrile of formula IVe (145 mg) was obtained. On elution with hexane/CH₂CI₂/Et₃N 96:4:0.4, an additional amount of nitrile IVe (97 mg) was isolated. The impure product was taken up in 5 N HCI (15 ml_) and washed with Et₂0 (3 x 10 ml_). The acidic aqueous phase was alkalinized with NaOH pellets and extracted with CH₂CI₂ (3 x 10 ml_). The combined organic extracts were dried over anhydrous Na₂S0₄, filtered, and evaporated at reduced pressure, to afford nitrile IVe (102 mg, 62% total yield) as a yellowish oil.

Characterization: IVe: R_f = 0.62 (hexane/CH₂CI₂/50% aq. NH₄OH 6:4:0.04); [a]²⁰ _D = +95 (c = 0.13, CH₂CI₂); IR (ATR) v: 2243 (CN st), 1606, 1577, 1556 (ar-C-C and ar-C-N st) cm ¹ ; HRMS (ESI) calcd for (C₂₂H₂₄ ³⁵CIN₃ + H⁺) 366.1732, found 366.1731.

Example 6: Preparation of 1-(1-(3-r(6-chloro-1 ,2,3,4-tetrahydroacridin-9- yl)aminolpropanoyl)piperidin-4-yl)-3-r4-(trifluoromethoxy)phenyl1urea, la (compound of formula I wherein: m = 1 ; n = 2; R₀ = Ri = R₃ = R₆ = R₇ = H; R₂ = Cl; R₅ = OCF₃)

A suspension of nitrile of formula IVa (150 mg, 0.52 mmol) in 5 N HCI (13 ml_) was heated under reflux for 3.5 h. The resulting mixture was evaporated to dryness to afford 3-[(6-chloro-1 ,2,3,4-tetrahydroacridin-9-yl)amino]propanoic acid (within formula II) (170 mg), in the form of the hydrochloride salt, as a yellowish solid, which was used in the following step without further purification. A suspension of this crude carboxylic acid (144 mg) in EtOAc/DMF 10: 1 (7.7 ml_) was treated successively with EDC HCI (121 mg, 0.63 mmol), HOBt (86 mg, 0.63 mmol) and Et₃N (0.3 ml_, 231 mg, 1.94 mmol). The mixture was stirred at room temperature for 10 min. To the resulting white suspension, a solution of 1-(piperidin-4-yl)-3-[4-(trifluoromethoxy)phenyl]urea (within formula III) (158 g, 0.46 mmol) in EtOAc/DMF 10: 1 (8.8 ml_) was added. The reaction mixture was stirred at room temperature overnight, and then it was concentrated at reduced pressure, to afford a crude product (708 mg), which was subjected to column chromatography [40-60 pm silica gel (35 g), CH₂CI₂/MeOH/50% aq. NH₄OH mixtures, gradient elution]. On elution with CH₂CI₂/MeOH/50% aq. NH₄OH 99:1 :0.2, the compound la of the title (1 13 mg, 45% yield) was isolated as a yellowish solid. The isolated compound of the title was transformed into the corresponding hydrochloride as follows: A solution of the free base (69 mg) in CH₂CI₂ (2 ml_) was filtered through a 0.2 pm PTFE filter and treated with excess of a solution of HCI in Et₂0. The solution was concentrated in vacuo to dryness and the solid was washed with EtOAc (2 x 2 ml_), hexane (2 x 2 ml_) and pentane (2 x 2 ml_), and was dried at 45 °C/2 Torr for 7 days to give la_*HCI (65 mg) as a yellowish solid. Characterization: la: R_f = 0.7 (CH₂CI₂/MeOH/50% aq. NH₄OH 9.5:0.5:0.2). la*HCI: mp 191-192 °C; IR (ATR) v: 3500-2500 (max at 3279, 3056, 2939, 2863, N-H/N-H, and C-H st), 1683, 1634, 1558, 1509 (ar-C-C and ar-C-N st) crrf¹ ; HRMS (ESI) calcd for (CzgHs^CIFsNsOs + H⁺) 590.2140, found 590.2137.

Example 7: Preparation of 1-{1-{4-[(6-chloro-1 ,2,3,4-tetrahvdroacridin-9- yl)amino1butanoyl)piperidin-4-yl)-3-[4-(trifluoromethoxy)phenyl1urea, lb (compound of formula I wherein: m = 1 ; n = 3; R₀ = Ri = R₃ = R₆ = R₇ = H; R₂ = Cl; R₅ = OCF₃)

It was prepared in an analogous manner to the one described for the compound of Example 6. From nitrile of formula IVb (400 mg, 1.33 mmol) and 5 N HCI (33 ml_), stirring the reaction mixture at 90 °C for 3 h, an orange oily residue was obtained. This solid was taken up in H₂0 (15 ml_), alkalinized with 10 N NaOH, and extracted with EtOAc (3 x 10 ml_). The combined organic extracts were dried over anhydrous Na₂S0₄, filtered, and evaporated at reduced pressure, to afford 1-(6-chloro-1 ,2,3,4-tetrahydroacridin-9- yl)pyrrolidin-2-one (254 mg, 64% yield) as a byproduct. On evaporation of the alkaline aqueous phase, a crude product (844 mg), containing the desired 4-[(6-chloro-1 , 2,3,4- tetrahydroacridin-9-yl)amino]butanoic acid (within formula II), in the form of sodium carboxylate salt, was obtained and used in the following step without further purification. From this crude carboxylic acid and 1-(piperidin-4-yl)-3-[4-(trifluoromethoxy)phenyl]urea (within formula III) (182 mg, 0.54 mmol), a crude product (1.38 g) was obtained and was subjected to column chromatography [40-60 pm silica gel (70 g), CH₂CI₂/MeOH/50% aq. NH₄OH mixtures, gradient elution]. On elution with CH₂CI₂/MeOH/50% aq. NH₄OH 98:2:0.2, the compound lb of the title (132 mg, 45% yield) was isolated as a yellowish solid. The isolated compound of the title was transformed into the corresponding hydrochloride as follows: A solution of the free base (132 mg) in CH₂CI₂ (1 ml_) was filtered through a 0.2 pm PTFE filter and treated with excess of a solution of HCI in Et₂0. The solution was concentrated in vacuo to dryness and the solid was washed with EtOAc (2 x 2 ml_), hexane (2 x 2 ml_) and pentane (2 x 2 ml_), and was dried at 45 °C/2 Torr for 7 days to give Ib-HCI (72 mg) as a yellowish solid. Characterization: lb: R_f = 0.5

(CH₂CI₂/MeOH/50% aq. NH₄OH 9.5:0.5:0.2). Ib-HCI: mp 195-197 °C; IR (ATR) v: 3500- 2500 (max at 3268, 3055, 2938, 2861 , N-H,⁺N-H, and C-H st), 1683, 1635, 1557, 1507 (ar-C-C and ar-C-N st) crrf¹; HRMS (ESI) calcd for (CsoHss^CIFsNsOs + H⁺) 604.2297, found 604.2287.

Example 8: Preparation of 1-(1-(5-r(6-chloro-1 ,2,3,4-tetrahydroacridin-9- yl)aminolpentanoyl)piperidin-4-yl)-3-r4-(trifluoromethoxy)phenyl1urea, lc (compound of formula I wherein: m = 1 ; n = 4; R₀ = Ri = R₃ = R₆ = R₇ = H; R₂ = Cl; R₅ = OCF₃)

A solution of nitrile of formula IVc (289 mg, 0.92 mmol) in MeOH (1.5 ml_) was treated with a 40% methanolic solution of KOH (2.5 ml_). The mixture was stirred under reflux for 4 h, then H₂0 (4 ml_) was added, and the reaction mixture was stirred under reflux overnight. The resulting suspension was cooled to room temperature and evaporated at reduced pressure. The solid residue was treated with excess of a solution of HCI in Et₂0 and the solution was evaporated to dryness, to afford 5-[(6-chloro-1 , 2,3,4- tetrahydroacridin-9-yl)amino]pentanoic acid (within formula II) (789 mg), in the form of hydrochloride salt, which was used in the following step without further purification. From this crude carboxylic acid and 1-(piperidin-4-yl)-3-[4-(trifluoromethoxy)phenyl]urea (within formula III) (313 mg, 0.92 mmol), in an analogous manner to the one described for the compound of Example 6, a crude product (2.09 g) was obtained and was subjected to column chromatography [40-60 pm silica gel (82 g), CH₂CI₂/MeOH/50% aq. NH₄OH mixtures, gradient elution]. On elution with CH₂CI₂/MeOH/50% aq. NH₄OH 98.5:1.5:0.4, the compound lc of the title (452 mg, 79% yield) was isolated as a light brown solid. The isolated compound of the title was transformed into the corresponding hydrochloride as follows: A solution of the free base (452 mg) in CH₂CI₂ (2 ml_) was filtered through a 0.2 pm PTFE filter and treated with excess of a solution of HCI in Et₂0. The solution was concentrated in vacuo to dryness and the solid was washed with EtOAc (2 x 5 ml_), hexane (2 x 5 ml_) and pentane (2 x 5 ml_), and was dried at 45 °C/2 Torr for 7 days to give lc_*HCI (411 mg) as a light brown solid. Characterization: lc: R_f = 0.22

(CH₂CI₂/MeOH/50% aq. NH₄OH 9.6:0.4:0.04). lc*HCI: mp 154-157 °C; IR (ATR) v: 3500- 2500 (max at 3278, 3062, 2936, 2871 , N-H,⁺N-H, and C-H st), 1688, 1631 , 1555, 1509 (ar-C-C and ar-C-N st) crrf¹; HRMS (ESI) calcd for

+ H⁺) 618.2453, found 618.2443.

Example 9: Preparation of (-)-(7S,11 S)-1-(1-(5-r(3-chloro-6,7,10,11-tetrahvdro-9-methyl- 7,11 -methanocyclooctarblquinolin-l 2-yl)aminolpentanoyl)piperidin-4-yl)-3-r4- (trifluoromethoxy)phenyllurea, Id (compound of formula I with (S,S) configurations, wherein: m form a bridge -CH₂-C(R₄ )=CH- with R₄ = CH₃; R₃ = R₆ = R₇ = H; R₂

It was prepared in an analogous manner to the one described for the compound of Example 8. From nitrile of formula IVd (206 mg, 0.56 mmol) and a 40% methanolic solution of KOH (1.6 ml_), (-)-(7S, 11 S)-5-[(3-chloro-6,7, 10,1 1-tetrahydro-9-methyl-7, 11- methanocycloocta[Jb]quinolin-12-yl)amino]pentanoic acid (within formula II) (1.55 g), in the form of hydrochloride salt, was obtained and was used in the following step without further purification. From this crude carboxylic acid and 1-(piperidin-4-yl)-3-[4-

(trifluoromethoxy)phenyl]urea (190 mg, 0.56 mmol) (within formula III), a crude product (2.28 g) was obtained and was subjected to column chromatography [40-60 pm silica gel (90 g), CH₂CI₂/MeOH/50% aq. NH₄OH mixtures, gradient elution]. On elution with CH₂CI₂/MeOH/50% aq. NH₄OH 98.5:1.5:0.4, the compound Id of the title (286 mg, 76% yield) was isolated as a light brown solid. The isolated compound of the title was transformed into the corresponding hydrochloride as follows: A solution of the free base (286 mg) in CH₂CI₂ (1 ml_) was filtered through a 0.2 pm PTFE filter and treated with excess of a solution of HCI in Et₂0. The solution was concentrated in vacuo to dryness and the solid was washed with EtOAc (2 x 5 ml_), hexane (2 x 5 ml_) and pentane (2 x 5 ml_), and was dried at 45 °C/2 Torr for 7 days to give Id-HCI (234 mg) as a grey solid.

Characterization: Id: R_f = 0.67 (CH₂CI₂/MeOH/50% aq. NH₄OH 9.5:0.5:0.04). Id-HCI: mp 177-180 °C; [a]²⁰ _D = -145 (c = 0.60, MeOH); IR (ATR) v: 3500-2500 (max at 3258, 3060, 2933, 2863, N-H,⁺N-H, and C-H st), 1682, 1633, 1583, 1554, 1509 (ar-C-C and ar-C- N st) cm ¹ ; HRMS (ESI) calcd for (C₃₅H₃₉ ³⁵CIF₃N₅0₃ + H⁺) 670.2766, found 670.2762.

Example 10: Preparation of (+)-(7f?, 11 f?)-1-{1-{5-[(3-chloro-6,7, 10,1 1-tetrahvdro-9- methyl-7, 11-methanocvclooctarb1quinolin-12-yl)aminolpentanoyl)piperidin-4-yl)-3-r4-

(trifluoromethoxy)phenyllurea, le (compound of formula I with (R,R) configurations, wherein: m form a bridge -CH₂-C(R₄ )=CH- with R₄ = CH₃; R₃ = R₆ = R₇ = H; R₂

It was prepared in an analogous manner to the one described for the compound of Example 8. From nitrile of formula IVe (102 mg, 0.28 mmol) and a 40% methanolic solution of KOH (0.8 ml_), (+)-(7R, 11 R)-5-[(3-chloro-6,7, 10,1 1-tetrahydro-9-methyl-7,1 1- methanocycloocta[Jb]quinolin-12-yl)amino]pentanoic acid (within formula II) (575 mg), in the form of hydrochloride salt, was obtained and was used in the following step without further purification. From this crude carboxylic acid and 1-(piperidin-4-yl)-3-[4- (trifluoromethoxy)phenyl]urea (within formula III) (104 mg, 0.30 mmol), a crude product (983 mg) was obtained and was subjected to column chromatography [40-60 pm silica gel (39 g), CH₂CI₂/MeOH/50% aq. NH₄OH mixtures, gradient elution]. On elution with CH₂CI₂/MeOH/50% aq. NH₄OH 99:1 :0.4 to 98:2:0.4, the compound le of the title (74 mg, 40% yield) was isolated as a light brown solid. The isolated compound le was

transformed into the corresponding hydrochloride as follows: A solution of the free base (74 mg) in CH₂CI₂ (1 ml_) was filtered through a 0.2 pm PTFE filter and treated with excess of a solution of HCI in MeOH. The solution was concentrated in vacuo to dryness and the solid was washed with EtOAc (5 ml_), hexane (5 ml_) and pentane (5 ml_), and was dried at 45 °C/2 Torr for 7 days to give le_*HCI (58 mg) as a light brown solid.

Characterization: le: R_f = 0.68 (CH₂CI₂/MeOH/50% aq. NH₄OH 9.5:0.5:0.04). le-HCI: mp 178-180 °C; [a]²⁰ _D = +138 (c = 0.54, MeOH); IR (ATR) v: 3500-2500 (max at 3272, 3073, 2935, 2860, N-H,⁺N-H, and C-H st), 1689, 1632, 1583, 1556, 1507 (ar-C-C and ar-C- N st) cm ¹ ; HRMS (ESI) calcd for (C₃₅H₃₉ ³⁵CIF₃N₅0₃ + H⁺) 670.2766, found 670.2762.

Example 1 1 : Preparation of 1-(1-(5-r(6-chloro-1 ,2,3,4-tetrahydroacridin-9- yl)aminolpentanoyl)piperidin-4-yl)-3-(3,4-difluorophenyl)urea, If (compound of formula I wherein: m = 1 ; n = 4; R₀ = Ri = R₃ = R₇ = H; R₂ = Cl; R₅ = R₆ = F)

It was prepared in an analogous manner to the one described for the compound of Example 8. From nitrile of formula IVc (4.08 g, 13.0 mmol) and a 40% methanolic solution of KOH (35 ml_), 5-[(6-chloro-1 ,2,3,4-tetrahydroacridin-9-yl)amino]pentanoic acid (within formula II) (3.60 g), in the form of hydrochloride salt, was obtained and was used in the following step without further purification. From this crude carboxylic acid (288 mg) and 1- (3,4-difluorophenyl)-3-(piperidin-4-yl)urea (288 mg, 1.13 mmol) (within formula III), and stirring the reaction mixture for 5 days, a crude product (398 mg) was obtained and was subjected to column chromatography [40-60 pm silica gel, CH₂CI₂/MeOH/Et₃N 4:1 :0.1]. The compound If of the title (333 mg, 56% yield) was isolated as a light brown solid. The isolated compound of the title was transformed into the corresponding hydrochloride as follows: A solution of the free base (140 mg) in a mixture of CH₂CI₂ (5 ml_) and MeOH (1 ml_) was treated with excess of a solution of HCI in Et₂0. The solution was filtered through a 4 pm fritted glass and concentrated in vacuo. The solid was dried at 20 °C/0.1 Torr for 5 days to give lf_*HCI (1 12 mg). Characterization: If: R_f = 0.31 (CH₂CI₂/MeOH/50% aq. NH₄OH 9.5:0.5:0.04). If-HCI: mp 94-95 °C; IR (ATR) v: 3500-2500 (max at 3263,

3055, 2930, N-H,⁺N-H, and C-H st), 1692, 1631 , 1573, 1539, 1512 (ar-C-C and ar-C- N st) cm ¹ ; HRMS (ESI) calcd for (C₃oH₃₄ ³⁵CIF₂N₅0₂ + H⁺) 570.2442, found 570.2437.

Example 12: Preparation of 1-(1-(5-r(6-chloro-1 ,2,3,4-tetrahydroacridin-9- yl)aminolpentanoyl)piperidin-4-yl)-3-r3-fluoro-4-(trifluoromethoxy)phenyl1urea, Ig

(compound of formula I wherein: m = 1 ; n = 4; R₀ = Ri = R₃ = R₇ = H; R₂ = Cl; R₅ = OCF₃; Re = F) It was prepared in an analogous manner to the one described for the compound of Example 8. From crude carboxylic acid of example 11 (432 mg) and 1-[3-fluoro-4- (trifluoromethoxy)phenyl]-3-(piperidin-4-yl)urea (443 mg, 1.38 mmol) (within formula III), and stirring the reaction mixture for 5 days, a crude product was obtained and was subjected to column chromatography [40-60 pm silica gel, CH₂CI₂/MeOH 6:1 to 3:1] The compound Ig of the title (542 mg, 55% yield) was isolated as a light brown solid. The isolated compound of the title was transformed into the corresponding hydrochloride as follows: A solution of the free base (174 mg) in a mixture of CH₂CI₂ (5 ml_) and MeOH (1 ml_) was treated with excess of a solution of HCI in Et₂0. The solution was filtered through a 4 pm fritted glass and concentrated in vacuo. The solid was dried at 20 °C/0.1 Torr for 5 days to give lg_*HCI (161 mg). Characterization: Ig: R_f = 0.28

(CH₂CI₂/MeOH/50% aq. NH₄OH 9.5:0.5:0.04). Ig-HCI: mp 126-127 °C; IR (ATR) v: 3500- 2500 (max at 3267, 3048, 2932, N-H,⁺N-H, and C-H st), 1694, 1632, 1606, 1574, 1557, 1510 (ar-C-C and ar-C-N st) crrf¹; HRMS (ESI) calcd for (C₃₁H34³⁵CIF4N50₃ + H⁺)

636.2359, found 636.2366.

Example 13: Preparation of 1-[benzo[cnri ,31dioxol-5-yl1-3-{1-{5-r(6-chloro-1 , 2,3,4- tetrahvdroacridin-9-yl)aminolpentanoyl)piperidin-4-yl)urea, Ih (compound of formula I wherein: m = 1 ; n = 4; R₀ = Ri = R₃ = R₇ = H; R₂ = Cl; R₅ and R₆ = -0-CH₂-0-)

It was prepared in an analogous manner to the one described for the compound of Example 8. From crude carboxylic acid of example 11 (432 mg) and 1- [benzo[d][1 ,3]dioxol-5-yl]-3-(piperidin-4-yl)urea (363 mg, 1.38 mmol) (within formula III), and stirring the reaction mixture for 5 days, a crude product (700 mg) was obtained and was subjected to column chromatography [40-60 pm silica gel, CH₂CI₂/MeOH 6:1 to 4:1] The compound Ih of the title (355 mg, 39% yield) was isolated as a light brown solid. The isolated compound of the title was transformed into the corresponding hydrochloride as follows: A solution of the free base (165 mg) in a mixture of CH₂CI₂ (5 ml_) and MeOH (1 ml_) was treated with excess of a solution of HCI in Et₂0. The solution was filtered through a 4 pm fritted glass and concentrated in vacuo. The solid was dried at 20 °C/0.1 Torr for 5 days to give Ih-HCI (163 mg). Characterization: Ih: R_f= 0.31

(CH₂CI₂/MeOH/50% aq. NH₄OH 9.5:0.5:0.04). Ih-HCI: mp 121-122 °C; IR (ATR) v: 3500- 2500 (max at 3265, 3062, 2922, 2871 , N-H,⁺N-H, and C-H st), 1692, 1631 , 1567, 1501 (ar-C-C and ar-C-N st) crrf¹; HRMS (ESI) calcd for (C₃₁H₃₆ ³⁵CIN₅0₄ + H⁺) 578.2529, found 578.2533. Example 14: Preparation of 1-(1-(5-r(6-chloro-1 ,2,3,4-tetrahydroacridin-9- yl)aminolpentanoyl)piperidin-4-yl)-3-r4-(methylsulfonyl)phenyl1urea, li (compound of formula I wherein: m = 1 ; n = 4; R₀ = Ri = R₃ = R₆ = R₇ = H; R₂ = Cl; R₅ = S0₂CH₃). It was prepared in an analogous manner to the one described for the compound of Example 8. From crude carboxylic acid of example 11 (288 mg) and 1-[4- (methylsulfonyl)phenyl]-3-(piperidin-4-yl)urea (273 mg, 0.92 mmol) (within formula III), and stirring the reaction mixture for 5 days, a crude product (361 mg) was obtained and was subjected to column chromatography [40-60 pm silica gel, CH₂CI₂/MeOH 6:1 to 3:1] The compound li of the title (104 mg, 16% yield) was isolated as a light brown solid. The isolated compound of the title was transformed into the corresponding hydrochloride as follows: A solution of the free base (104 mg) in a mixture of CH₂CI₂ (5 ml_) and MeOH (1 ml_) was treated with excess of a solution of HCI in Et₂0. The solution was filtered through a 4 pm fritted glass and concentrated in vacuo. The solid was dried at 20 °C/0.1 Torr for 5 days to give IhHCI (74 mg). Characterization: li: R_f = 0.24 (CH₂CI₂/MeOH/50% aq. NH₄OH 9.5:0.5:0.04). li-HCI: mp 183-184 °C; IR (ATR) v: 3500-2500 (max at 3259, 3053, 2927, N-H,⁺N-H, and C-H st), 1699, 1631 , 1587, 1537 (ar-C-C and ar-C-N st) cm ¹; HRMS (ESI) calcd for (C₃₁H₃₈ ³⁵CIN₅0₄S + H⁺) 612.2406, found 612.2398. Example 15: In vitro determination of sEH inhibitory activity

The following fluorescent assay was used for determination of the sEH inhibition activity (IC₅₀), with the substrate and comparative control compound (TPPU) indicated below. Substrate: cyano(6-methoxynaphthalen-2-yl)methyl 2-(3-phenyloxiran-2-yl)acetate (PHOME; from Cayman Chemical, item number 10009134; CAS 1028430-42-3). Cf. N.M. Wolf et al., "Development of a high-throughput screen for soluble epoxide hydrolase inhibition", Anal. Biochem. 2006, vol. 355, pp. 71-80.

TPPU: N-[ 1 -(1 -oxopropyl)-4-piperidinyl]-/\/ -[4-(trifluoromethoxy)phenyl]urea.

Solutions:

- Assay buffer: Bis/Tris HCI 25 mM pH 7.0 containing 0.1 mg/ml_ of bovine serum albumin

(BSA).

- PHOME at 200 pM in DMSO.

- Solution of recombinant human sEH (hsEH) (Cayman Chemical, item number

10011669), diluted with assay buffer.

- Inhibitors dissolved in DMSO at appropriated concentrations.

Protocol: In a black 96-well plate (Greiner Bio-One, item number 655900), fill the background wells with 90 pL and the positive control and inhibitor wells with 85 pL of assay buffer. Add 5 pL of DMSO to background and positive control wells, and then add 5 pL of inhibitor solution in inhibitor wells. Add 5 pL of the solution of hsEH to the positive control and inhibitor wells and stir the mixture. Prepare a 1/21 dilution of the solution of PHOME with assay buffer according to final volume required, and then add 105 pl_ to each well. Shake carefully the plate for 10 seconds and incubate for 5 minutes at room temperature. Read the appearance of fluorescence with excitation wavelength: 337 nm, and emission wavelength: 460 nm (FLUOStar OPTIMA microplate reader, BMG). The intensity of fluorescence was used to analyze and calculate the IC₅₀ values. Results were obtained by regression analysis from at least three data points in a linear region of the curve. The sEH inhibitory activities of the hydrochlorides of compounds la-li are summarized in Table 1.

Table 1 : Human sEH inhibitory activity of compounds la-li*

* A means that IC₅₀ is lower than 10 nM, B means that IC₅₀ is at least 10 nM but less than

50 nM, C means that IC₅₀ is at least 50 nM but less than 100 nM, and D means that IC₅₀ is at least 100 nM but less than 2000 nM.

Example 16: In vitro determination of acetylcholinesterase inhibitory activity

The AChE inhibitory activity of compounds la-li was evaluated spectrophotometrically at 25 °C by the method of Ellman et al. , using human recombinant AChE (hAChE) and acetylthiocholine iodide as substrate (cf. G.L. Ellman et al., "New and Rapid Colorimetric Determination of Acetylcholinesterase Activity", Biochem. Pharmacol. 1961 , vol. 7, pp. 88-95). The AChE stock solution was prepared by dissolving hAChE lyophilized powder in 0.1% Triton X-100/0.1 M potassium phosphate, pH 8.0. The stock solutions of the novel compounds (1 mM) were prepared in MeOH. The assay solution contained 340 mM 5,5’-dithiobis(2-nitrobenzoic acid) (DTNB), 0.02 unit/mL hAChE, and 550 mM substrate (acetylthiocholine iodide), in 0.1 M potassium phosphate, pH 8.0. Assay solutions with and without inhibitor were preincubated at 37 °C for 20 min, and then the substrate was added. Blank solutions containing all components except the enzyme were prepared in parallel to correct for non-enzymatic hydrolysis of the substrate. Initial rate assays were performed at 37 °C with a Jasco V-530 double beam spectrophotometer. At least five increasing concentrations of the inhibitors, which produced 20-80% inhibition of the enzymatic activity, were assayed. IC₅₀ values were calculated using Microcal Origin 3.5 software (Microcal Software, Inc). DTNB, acetylthiocholine, and the enzyme were purchased from Sigma. The hAChE inhibitory activities of the hydrochlorides of compounds la-li are summarized in Table 2.

Table 2: Human AChE inhibitory activity of compounds la-li*

* A means that IC₅₀ is lower than 10 nM, B means that IC₅₀ is at least 10 nM but less than 50 nM, C means that IC₅₀ is at least 50 nM but less than 100 nM, and D means that IC₅₀ is at least 100 nM but less than 2000 nM.

Example 17: Parallel Artificial Membrane Permeation Assay - Blood-Brain Barrier To evaluate the brain penetration of the different compounds, a parallel artificial membrane permeation assay for blood-brain barrier (PAMPA-BBB) was used, following the method described by L. Di et al. , "High throughput artificial membrane permeability assay for blood-brain barrier", Eur. J. Med. Chem. 2003, vol. 38. pp. 223-232. The in vitro permeability (Pe) of the test compounds through lipid extract of porcine brain membrane was determined. Assayed compounds were tested using a mixture of PBS:EtOH (70:30). Assay validation was made by comparing the experimental and reported permeability values of a set of fourteen commercial drugs and lineal correlation between experimental and reported permeability of the fourteen commercial drugs using the PAMPA-BBB assay was evaluated (y = 1.637 x - 1.3134; R² = 0.9348). From this equation and taking into account the limits established by Di et al. for BBB permeation, the ranges of permeability were established, as follows. Compounds of high BBB permeation (CNS+): Pe (10⁶ cm s ¹) > 5.235; compounds of low BBB permeation (CNS-): Pe (10⁶ cm s ¹) < 1.961 ; and compounds of uncertain BBB permeation (CNS+/-): 5.235 > Pe (10⁶ cm s ¹) > 1.961. The permeability results from the assayed compounds are averages of three different experiments in triplicate and a predictive penetration in the CNS is also given. The PAMPA-BBB permeabilities of the hydrochlorides of compounds la-li are summarized in Table 3. Table 3: Blood-brain barrier permeability of la-li

Claims

Claim 1. A compound of formula I, or a pharmaceutically acceptable salt thereof,

wherein:

m is 0, 1 or 2;

n is 2, 3, 4 or 5;

R₀ and R^ are both H, or they form a bridge -CH₂-C(R₄ )=CH- wherein R₄ is CH₃ or CH₂CH₃ ;

R₂ and R₃ are radicals independently selected from the group consisting of: H, F, Cl and (CrC₄)-alkyl;

optionally R₇ is H, and R₅ and R₆ form a bridge -0-CH₂ -O- .

Claim 2. The compound according to claim 1 , wherein m is 1.

Claim 3. The compound according to any one of claims 1-2, wherein R₃ is H.

Claim 4. The compound according to any one of claims 1-3, wherein R₂ is Cl.

Claim 5. The compound according to any one of claims 1-4, wherein R₆ is H or F; and R₇ is H.

Claim 6. The compound according to any one of claims 1-5, wherein R₅ is OCF₃ , F , or S0₂CH₃ .

Claim 7. The compound according to any one of claims 1-6, wherein R₀ and R^ are both H, having the formula:

Claim 8. The compound according to any one of claims 1-6, wherein R₀ and

form a bridge -CH₂-C(R₄ )=CH-, having the formula shown below, with the proviso that the two carbon atoms where the bridge is attached have configurations which are either (R,R) or (S,S).

Claim 9. The compound according to claim 8, wherein the two carbon atoms where the bridge is attached have configurations (S,S).

Claim 10. The compound according to claim 4, which is selected from the group consisting of:

1-{1-{3-[(6-chloro-1 ,2,3,4-tetrahydroacridin-9-yl)amino]propanoyl}piperidin-4-yl}-3-[4- (trifluoromethoxy)phenyl]urea (la);

1-{1-{4-[(6-chloro-1 ,2,3,4-tetrahydroacridin-9-yl)amino]butanoyl}piperidin-4-yl}-3-[4- (trifluoromethoxy)phenyl]urea (lb);

1-{1-{5-[(6-chloro-1 ,2,3,4-tetrahydroacridin-9-yl)amino]pentanoyl}piperidin-4-yl}-3-[4- (trifluoromethoxy)phenyl]urea (lc);

(-M7S, 11 S)-1 -{1 -{5-[(3-chloro-6,7, 10,11 -tetrahydro-9-methyl-7, 11 - methanocycloocta[Jb]quinolin-12-yl)amino]pentanoyl}piperidin-4-yl}-3-[4- (trifluoromethoxy)phenyl]urea (Id);

(+)-(7 R, 11 R)-1 -{1 -{5-[(3-chloro-6,7, 10,11 -tetrahydro-9-methyl-7, 11 - methanocycloocta[Jb]quinolin-12-yl)amino]pentanoyl}piperidin-4-yl}-3-[4- (trifluoromethoxy)phenyl]urea (le);

1-{1-{5-[(6-chloro-1 ,2,3,4-tetrahydroacridin-9-yl)amino]pentanoyl}piperidin-4-yl}-3-(3,4- difluorophenyl)urea (If); 1-{1-{5-[(6-chloro-1 ,2,3,4-tetrahydroacridin-9-yl)amino]pentanoyl}piperidin-4-yl}-3-[3- fluoro-4-(trifluoromethoxy)phenyl]urea (Ig);

1-[benzo[d][1 ,3]dioxol-5-yl]-3-{1-{5-[(6-chloro-1 ,2,3,4-tetrahydroacridin-9- yl)amino]pentanoyl}piperidin-4-yl}urea (Ih); and

1-{1-{5-[(6-chloro-1 ,2,3,4-tetrahydroacridin-9-yl)amino]pentanoyl}piperidin-4-yl}-3-[4- (methylsulfonyl)phenyl]urea (li).

Claim 11. A pharmaceutical composition comprising an effective amount of a compound as defined in any one of claims 1-10 or a pharmaceutically acceptable salt thereof, together with adequate amounts of pharmaceutically acceptable excipients or carriers.

Claim 12. A compound as defined in any one of claims 1-10 or a pharmaceutically acceptable salt thereof, for use as an active pharmaceutical ingredient.

Claim 13. A compound as defined in any one of claims 1-10 or a pharmaceutically acceptable salt thereof, for use in the treatment of Alzheimer’s disease.