WO2007074491A1

WO2007074491A1 - HETEROTRICYCLIC AMIDE DERIVATIVES AS NEUROKININ-l (NKl) RECEPTOR LIGANDS

Info

Publication number: WO2007074491A1
Application number: PCT/IT2006/000860
Authority: WO
Inventors: Andrea Cappelli; Germano Giuliani; Maurizio Anzini; Salvatore Vomero
Original assignee: Universita Degli Studi Di Siena
Priority date: 2005-12-28
Filing date: 2006-12-20
Publication date: 2007-07-05
Also published as: WO2007074491A8; WO2007074491B1

Abstract

The present invention relates to compounds of formula 1, method of preparation and uses thereof.

Description

HETEROTRICYCLIC AMIDE DERIVATIVES AS NEUROKININ-! (NKl) RECEPTOR LIGANDS

Introduction

Substance P (SP) is an undecapeptide member of the tachykinin family. The comparative analysis of the pharmacological properties of various tachykinins has provided evidence for the existence of three receptor subtypes (termed NK₁, NK₂, and NK₃) showing different preferences in the interaction with their endogenous ligands. All the tachykinin receptors identified up to now belong to the family of the G-protein coupled receptors (GPCRs) and are linked to the inositol phosphate signal transduction pathway (Snider et al., 1991). By interacting with the NK₁ receptor, SP elicits a wide variety of biological responses including the transmission of pain and stress signals, smooth muscle contraction, the induction of neurogenic inflammation, endothelium-dependent vasodilation, and angiogenesis. NK₁ receptor antagonists are reported to be useful in the treatment of motion sickness and in that of cisplatin-induced emesis (Navari et al., 1999).

The usefulness of NK₁ receptor antagonists for the treatment of certain form of urinary incontinence is described in Maggi et al.,1998 and Doi et al., 1999.

Moreover NK₁ receptor antagonists are being developed for the treatment of a number of physiological disorders associated with an excess or imbalance of tachykinin, in particular SP. Examples of conditions in which SP is implicated include disorders of the central nervous system such as anxiety, depression and psychosis (WO 95/16679, WO 95/18124 and WO 95/23798).

Furthermore, U.S. Pat. No. 5,972,938 describes a method for the treatment of a psychoimmunologic or a psychosomatic disorder by administration of a tachykinin receptor, such as NK₁ receptor antagonist.

Evidence for the clinical usefulness of NK₁ receptor antagonists in the treatment of pain, headache (especially migraine) Alzheimer's disease, multiple sclerosis, attenuation of morphine withdrawal, cardiovascular changes, edema such as edema caused by terminal injury, chronic inflammatory diseases such as rheumatoid arthritis, asthma/bronchial hyperreactivity and other respiratory diseases including allergic rhinitis, inflammatory disease of the gut including ulcerative colitis and Crohn's disease, ocular injury and ocular inflammatory disease has been reviewed in Maggi et al., 1993. Astrocytes have been described, to express functional receptors to numerous neurotransmitters including SP, which is an important stimulus for reactive astrocytes are triggered by tachykinins via NK₁ receptors to release soluble mediators and to increase their proliferation rate (Palma et al., 2000). Therefore, selective NK₁ receptor antagonists may be useful as a therapeutic approach to malignant gliomas.

Since mice with a genetic disruption OfNK₁ receptor have been described to show a loss of the rewarding properties of morphine (Mutra et al., 2000), NK₁ receptor antagonists may be useful in the treatment of withdrawal symptoms in drug addiction of opiates and nicotine and in the reduction of their craving. On the other hand until recent time, the agonism for this receptors appeared to be confined to peptide compounds since potent non-peptide agonists have been lacking, in spite of the huge amount of work performed in this field. Recently, we have described the preparation and the pharmacological evaluation of a series of 3-quinolinecarboxamides bearing the 3,5- bis(trifluoromethyl)benzyl group as the main substiruent of the amide nitrogen and different substituents in position 2 of the quinoline. This structure-affinity relationship study has led to the discovery of several potent NK₁ receptor ligands endowed with picomolar affinity and, in particular, of the first non-peptide NK₁ receptor agonist showing very high potency in stimulating endothelial cell proliferation, inositol phosphate turnover, and NO-mediated cyclic GMP accumulation. The discovery of non-peptide tachykinin agonists can be of therapeutical relevance in angiogenesis-dependent diseases where endothelial cell proliferation is required to promote vascularization and healing of ischemic or damaged tissues (Cappelli et al., 2004) .

The whole research shows that there is a great therapeutic need to find novel, ever more potent and better tolerated drugs with high affinity for the NK₁ receptor (irrespectively of their agonist or antagonist activities).

In accordance with this need, the object of thev present invention is to provide novel drug treatments having potent NK₁ receptor affinity for the treatment of all pathological conditions in both central and peripheral nervous systems.

Detailed Description

The subject of the present invention is a novel compound, amide derivative, represented by the general formula (1):

wherein X, Y, Z are CH or N;

R₁ is H, CH₃ or a linear alkyl unsubstituted or substituted;

R₂ and R₃ represent an hydrogen, an halogen, an hydrocarbon group unsubstituted or substituted, or an hydroxyl group unsubstituted or substituted;

R₄ represents an hydrogen, an halogen, a linear alkyl group unsubstituted or substituted or an hydroxyl group; ^l and pharmaceutically acceptable salts thereof produced from inorganic or organic acids. Preferably R₂ and R₃ are a trifluoromethyl or a methoxy group. More preferably, R₄ is F or CH₃. Even more preferably the compound is N-[3,5-Bis(trifluoromethyl)benzyl]-5- phenylpyrrolo[l ,2-α]qumoline-4-carboxamide, or N-[3,5-Bis(trifluoromethyl)benzyl]-N- methyl-5-phenylpyrrolo[l,2-α]quinoline-4-carboxamide or N-[3,5-

Bis(trifluoromethyl)benzyl]-5-phenylimidazo[l,2-α]quinoline-4-carboxamide or N-[3,5- bis(trifluoromethyl)benzyl]-N-methyl-5-phenylimidazo[l,2-α]quinoline-4-carboxamide or N- [3 ,5 -Bis(trifluoromethyl)benzyl] -5 -phenylimidazo [ 1 , 5 -a] quinoline-4-carboxamide or N- [3 ,5 -Bis(trifiuoromethyl)benzyl] -N-methyl-5 -phenylimidazo [ 1 , 5 -a] quinoline-4- carboxamide or N-[3,5-Bis(trifluoromethyl)benzyl]-5-phenyl[l,2,4]triazolo[4,3- α]quinoline-4-carboxamide or N-[3,5-Bis(trifluoromethyl)benzyl]-N-methyl-5- phenyl[l,2,4]triazolo[4,3-α]quinolme-4-carboxamide or N-[3,5-

Bis(trifluoromethyl)benzyl]-5-phenyltetrazolo[l,5-α]quinoline-4-carboxamide or N-[3,5- Bis(trifluoromethyl)benzyl]-N-methyl-5-phenyltetrazolo[l,5-α]quinoline-4-carboxamide or N- [3 ,5 -Bis(trifluoromethyl)benzyl] -5 -(4-methylphenyl)tetrazolo [ 1 ,5 -a] quinoline-4- carboxamide or N-[3,5-Bis(trifluoromethyl)benzyl]-N-methyl-5-(4- methylphenyl)tetrazolo[l,5-α]quinoline-4-carboxamide or N-[3,5-

Bis(trifluoromethyl)benzyl]-5-(4-fluorophenyl)tetrazolo[ 1 ,5-«]quinoline-4-carboxamide or N-[3,5-Bis(trifluoromethyl)benzyl]-5-(4-fluorophenyl)-N-methyltetrazolo[l,5-α]quinolme- 4-carboxamide or N-(2-methoxybenzyl)-5-phenyltetrazolo[l ,5-α]quinoline-4-carboxamide or N-(3,5-dimethoxybenzyl)-5-phenyltetrazolo[l,5-α]quinoline-4-carboxamide. Preferably, the compounds of the invention are for medical use. It is also an object of the present invention a pharmaceutical composition comprising in an acceptable and effective amount the compound of formula 1 and suitable excipients. The pharmaceutical composition comprise between 0.00001 % (v/v or w/v or v/w) and 100% (v/v or w/v or v/w) of the compound of formula 1. Pharmaceutical compositions comprising the compounds of the invention can be prepared by conventional techniques, for example, as tablets, capsules, suspensions, solutions, suppositories or patches, and may be administered orally, parenterally, rectally or transdermally, or as other forms suitable for achieving the therapeutic effect such as, for example, solid preparations for oral use with protracted actions which permit controlled release of the active substance over time. For parenteral administration, the use of water-soluble salts of the compounds of the invention, such as the hydrochloride or another non-toxic and pharmaceutically acceptable salt, is preferable. As inactive ingredients, substance commonly used in pharmaceutical technology such as excipients, binders, flavourings, disaggregants, colorings, humectants, etc. may be used.

A further object of the invention is a method for the treatment of spontaneous or post- operative or cytostatic therapy-induced nausea and/or vomiting comprising the administration of the compound of the invention or a pharmaceutically acceptable salt thereof.

Another object of the invention is a method for the treatment of a pathological condition of the CNS connected with an imbalance in the physiological neuronal level of substance P comprising the administration of the compound of the invention or a pharmaceutically acceptable salt thereof. Preferably, the pathological condition is selected from the group consisting of anxiety, panic attack, psychosis, depression, Alzheimer's disease, Parkinson's disease, multiple sclerosis.

Forms object of the present invention a method for the treatment of a disorder of the gastrointestinal system comprising the administration of the compound of the invention or a pharmaceutically acceptable salt thereof. Preferably,- the disorder is selected from the group consisting of functional bowel diseases such as irritable bowel syndrome (IBS). It is also an object of the present invention a method for the treatment of angiogenesis- dependent diseases comprising the administration of the compound of the invention or a pharmaceutically acceptable salt thereof.

A further object of the invention is a method for the preparation of a compound of formula 1 comprising the step of transforming an acid of formula 23 into amide derivative with an suitable amine, at least a suitable activating agent and at least a suitable solvent.

Preferably, the suitable solvent is CH₂Cl₂, TEA, EtOAc, DMF, the suitable activating agent is dicyclohexylcarbodiimide (DCC), 1-hydroxybenzotriazole (HOBt), 2,3,5,6- tetrafluorophenol (TFP-OH), EDC, or thionyl chloride.

Another object of the invention is a method for the preparation of an intermediate acid compound of formula 5 comprising the following steps:

a) reacting commercially available 2-benzylahiline (2, Scheme 1) with 2,5- dimethoxytetrahydrofuran in glacial acetic acid to give intermediate 3; b) reacting 3 with ethyl oxalylchloride in a suitable solvent or a solvent mixture to give 4 (scheme 1); c) cyclizing 4 in the presence of a suitable base in a suitable solvent to obtain the carboxylic acid derivate 5.

Preferably, the suitable solvent in b) is benzene, the suitable base in c) is sodium hydride and the suitable solvent in c) is anhydrous DMF. ^" Another object of the invention is a method for the preparation of an intermediate acid compond of formula 10 comprising the following steps:

10

a) cyclizing hydroxyethylamino intermediate 7 into the corresponding imidazo[l,2- a]quinoline derivative 8 with a suitable dehydrating agent (scheme 2); b) oxidazing 8 with a suitable oxidizing agent to give an ester 9 (scheme 2); c) hydrolyzing the ester 9 in the presence of a suitable base to obtain the carboxylic acid derivate 10.

Preferably, the suitable dehydrating agent in a) is phosphorous oxychloride, the suitable oxidizing agent in b) is DMSO and the suitable base in c) is sodium hydroxide.

Another object of the invention is a method for the preparation of an intermediate acid compound of formula 15 comprising the following steps:

a) reacting 2-chloroquinoline derivative 11 with t-butyl isocyanoacetate in the presence of a suitable base in a suitable solvent to obtain the imidazo[l,5- a]quinoline derivative 12 (scheme 3); b) cleaving 12 with a suitable acid to give 13 (scheme 3); c) decarboxylating acid 13 into ester 14 (scheme 3). d) hydrolysing ester 14 in the presence of a suitable base to obtain the carboxylic acid derivate 15.

Preferably, the suitable base in a) is t-BuOK, the suitable solvent in a) is anhydrous DMF, the suitable acid in b) is formic acid and the suitable base in d) is sodium hydroxide. The methods for preparing the amide derivatives of the present invention consist of series of reactions which are reported below as non-limiting examples (Schemes 1-5).

Scheme 1

Reagents: (i) 2,5-Dimethoxytetrahydrofuran, CH₃COOH ; (ii) ClCOCOOC₂H₅, C₆H₆; (iii) NaH, DMF; (iv) 3,5-(CFa)₂C₆H₃CH₂NH₂, HOBt, DCC, CH₂Cl₂ or 3,5-(CF₃)₂C₆H₃CH₂N(H)CH₃-HCl, TEA, HOBt, DCC, CH₂Cl₂.

The synthesis of pyrrolo[l,2-α]quinoline derivatives la,b was accomplished starting from commercially available 2-benzylaniline (2) as -reported in Scheme 1. Compound 2 was subjected to Clauson-Kaas reaction, with 2,5-dimethoxytetrahydrofuran in glacial acetic acid to give intermediate 3, which reacted with ethyl oxalylchloride to give 4. This intermediate was then cyclized in the presence of sodium hydride as the base to obtain the carboxylic acid derivate 5 instead of the expected ester. Reaction between 5 and the appropriate amines in the presence of dicyclohexylcarbodiimide (DCC) and 1- hydroxybenzotriazole (HOBt) afforded the target compounds la,b.

Scheme 2

Reagents: (i) HOCH₂CH₂NH₂, C₂H₅OH; (ii) POCl₃; (iii) Δ, DMSO; (iv) NaOH, C₂H₅OH; (v) (a) TFP-OH, EDC, EtOAc; (b) 3,5-(CFs)₂C₆H₃CH₂NH₂, DMF, or 3,5-(CF₃)₂C₆H₃CH₂N(H)CH₃-HCl, TEA, DMF.

The procedure for the preparation of imidazo[l,2-α]quinoline amides lc,d is shown in Scheme 2. 2-Chloroquinoline derivate 6 (Anzini et al., 1991) was reacted with 2- aminoethanol to obtain 7, which was cyclized in phosphorus oxychloride to give the dihydroderivative 8. The heating of 8 in DMSO at 120 °C gave ester 9, which was hydrolyzed with 2M NaOH to give acid 10. The target amides lc,d were prepared from acid 10 by means of the 2,3,5,6-tetrafluorophenol (TFP-OH) activated ester procedure (Wilbur et al., 1997).

Scheme 3

Reagents: (i) t-Butyl isocyanoacetate, t-BuOK, DMF; (ii) HCOOH; (iii) Δ, no-solvent (neat), N₂; (iv) NaOH, C₂H₅OH; (v) 3, 5 -(CF_B)₂C₆H₃CH₂NH₂, HOBt, DCC, CH₂Cl₂ or 3,5- (CF₃)₂C₆H₃CH₂N(H)CH₃-HC1, TEA, HOBt, DCC, CH₂Cl₂.

The synthesis of imidazo[l,5-α]quinoline amides le,f is reported in Scheme 3. 2- Chloroquinoline derivate 11 (Anzini et al., 1991) was reacted with t-butyl isocyanoacetate in the presence of potassium t-butoxide to obtain diester 12, which was cleaved with formic acid to 13. Acid 13 was decarboxylated under nitrogen at 200 °C to give monoester 14, which was in turn hydrolyzed with NaOH 2 M to give acid 15. The target amides le,f were prepared from acid 15 by means of the same procedure described for the corresponding pyrrolo[l,2-α]quinoline amides la,b.

The synthesis of [l,2,4]triazolo[4,3-α]quinoline derivates lg,h was carried out starting from acid 16 (Anzini et al., 1991) as shown in Scheme 4. Acid 16 was converted into the corresponding amides 17a and 17b (US5482967, EP0585913), which reacted with phosphorus oxychloride to give chloroderivatives 18a and 18b (US5482967, EP0585913). The reaction of 18a and 18b with hydrazine hydrate gave hydrazinoderivatives 19a and 19b, respectively, which were cyclized with formic acid to obtain target compounds lg,h. Scheme 4

Reagents: (i) (a) SOCl₂, CH₂Cl₂; (b) 3,5-(CFj)₂C₆H₃CH₂NH₂, TEA, CH₂Cl₂ or 3,5- (CFa)₂C₆H₃CH₂N(H)CH₃-HCl, TEA, CH₂Cl₂ (ii) POCl₃, CH₂Cl₂; (iii) NH₂NH₂ H₂O, C₂H₅OH; (iv) HCOOH.

The synthesis of tetrazolo[l,5-α]quinoline-4-carboxamides li-p is described in Scheme 5. The preparation of 2-chloroquinoline derivative 11 (Anzini et al., 1991), 4-(4- methylphenyl)quinoline derivative 20b (Cappelli et al., 2004b), 4-(4- fluorophenyl)quinoline derivative 20c (Suzuki et al., 2001) was performed by means of procedures described in the literature.

The reaction of 2-chloroquinoline derivatives 11, 20b,c with sodium azide gave the key intermediates 21a,b,c (Scheme 5) which were hydrolyzed to obtain the required carboxylic acids 22a,b,c. The activation of these acids with thionyl chloride followed by the reaction with the suitable amines gave tetrazolo[l,5-α]quinoline-4-carboxamides li-p (Table 1). Scheme 5

22a,b,c 1 1-p

Reagents: (i) NaN₃, DMF; (ii) NaOH, C₂H₅OH; (iii) (a) SOCl₂, CH₂Cl₂; (b) R₂R₃C₆H₃CH₂N(H)R₁, TEA, CH₂Cl₂.

Table 1 : Compounds Ii to Ip

Compd Ri R₂ R₃ R₄

Ii H 3-CF₃ 5-CF₃ H

Ij CH₃ 3-CF₃ 5-CF₃ H

Ik H 3-CF₃ 5-CF₃ CH₃

11 CH₃ 3-CF₃ 5-CF₃ CH₃

Im H 3-CF₃ 5-CF₃ F

In CH₃ 3-CF₃ 5-CF₃ ^". F

Io H 2-OCH₃ H H ip H 3-OCH₃ 5-OCH₃ H

The invention will now be described by means of non-limiting examples. Examples

Example 1 l-(2-Benzylphenyl)-lH-pyrro!e (compound 3 of scheme 1)

A mixture of 2-benzylaniline (2, 0.30 g, 1.64 mmol) in glacial acetic acid (15 mL) with 2,5-dimethoxytetrahydrofuran (0.26 mL, 1.96 mmol) was heated at 80 °C for 2 h. The solvent was then removed under reduced pressure and the residue was partitioned between ethyl acetate and water. The organic layer was washed with brine, dried over sodium sulfate, and concentrated under reduced pressure. Purification of the residue by flash chromatography with n-hexane-ethyl acetate (8:2) as the eluent gave compound 3 as an orange oil (0.32 g, yield 84%). ¹H-NMR (CDCl₃): 3.93 (s, 2H), 6.35 (t, J= 1.8, 2H), 6.79

(t, J= 1.9, 2H), 7.07 (m, 2H), 7.22-7.35 (m, 7H>.

Example 2

Ethyl 2-[l-(2-Benzylphenyl)-lH-pyrrol-2-yl]-2-oxoacetate (compound 4 of scheme 1) To a solution of 3 (0.15 g, 0.64 mmol) in benzene (15 mL) was added ethyl oxalylchloride (0.22 mL, 1.97 mmol) and the resulting mixture was refluxed for 4 h. After concentration under reduced pressure, the residue was diluted with ethyl acetate, washed with saturated NaHCO₃ solution, dried over sodium sulfate, and concentrated under reduced pressure. Purification of the residue by flash chromatography with π-hexane-ethyl acetate (8:2) as the eluent gave pure 4 as a pale yellow oil (0.15 g, yield 70 %). ¹H-NMR (CDCl₃): 1.38 (t, J= 7.0, 3H), 3.63 (d, J= 15.6, IH), 3.80 (d, J= 15.6, IH), 4.36 (q, J= 7.0, 2H), 6.34 (m, IH), 6.83 (m, IH), 6.98 (m, 2H), 7.11-7.41 (m, 7H), 7.47 (m, IH). MS(ESI): m/z 334 (M+H⁺).

\. Example 3

5-Phenylpyrrolo[l,2-α]quinoline-4-carboxylic Acid (compound 5 of scheme 1) To a solution of 4 (0.80 g, 2.4 mmol) in anhydrous DMF (8 mL) was added NaH (0.115 g, 4.8 mmol) and the resulting mixture was heated for 3 h at 120 °C under argon. The solvent was then removed under reduced pressure and the resulting residue was diluted with ethyl acetate and washed with water. The organic layer was dried over sodium sulfate and concentrated under reduced pressure. Purification of the residue by flash chromatography with ethyl acetate as the eluent gave pure acid 5 as a yellow oil which crystallized on standing (0.50 g, yield 72.5 %, mp 168-169 ⁰C). ¹H-NMR (CDCl₃): 6.85 (m, 2H), 7.18- 7.61 (m, 8H)₅ 7.95 (m, 2H). MS(ESI, negative ions): m/z 286 (M-H⁺).

Example 4 N- [3,5-Bis(trifluoromethyl)benzyl]-5-phenylpyrrolo [1 ,2-α] quinoline-4-carboxamide (compound Ia of scheme 1)

To an ice-cooled mixture of 5 φ.115 g, 0.40 mmol) and 3,5- bis(trifluoromethyl)benzylamine (0.105 g, 0.43 mmol) in dry dichloromethane (20 rnL) was added HOBt (0.058 g, 0.43 mmol) and the resulting mixture was stirred at 0-5 °C for 10 min. Afterward, a solution of DCC (0.112 g, 0.54 mmol) in the same solvent (10 mL) was added dropwise. The reaction mixture was stirred overnight at room temperature; the precipitate was filtered-off and the filtrate washed in sequence with water and brine, dried and concentrated under reduced pressure. The residue was purified by flash chromatography with dichloromethane as eluent to give Ia (0.14 g, yield 68 %). An analytical sample crystallized from diethyl ether melted at 202-203 °C. ¹H-NMR (CDCl₃): 4.40 (d, J= 6.2, 2H), 5.79 (t, J= 6.0, IH), 6.70 (m, IH), 6.85 (m, IH), 7.17-7.58 (m, 10H), 7.76 (s, IH), 7.92 (m, 2H). MS(ESI): m/z 513 (M+H⁺).

Example 5 N- [3,5-Bis(trifluoromethyl)benzyl]-N-methyl-5-phenylpyrrolo [1 ,2-α] quinoline-4- carboxamide (compound Ib of scheme 1)

This compound was prepared from 5 (0.50 g, 1.74 mmol), 15 mL of dry dichloromethane, HOBt (0.27 g, 2.0 mmol), DCC (0.54 g, 2.6 mmol), 0.50 mL of TEA and N-[3,5- bis(trifluoromethyl)benzyl]methylamine hydrochloride (0.59 g, 2.0 mmol) by the same procedure described for the synthesis of Ia. The mixture was purified by flash chromatography with CH₂Cl₂ as the eluent to obtain Ib as a white solid (0.58 g, yield 63 %, melting point 161 °C). The ¹H-NMR spectrum of this amide shows the presence of two different rotamers in equilibrium. For the sake of simplification the integral intensities have not been given. ¹H-NMR (CDCl₃): 2.71 (s), 2.74 (s), 3.93 (d, J = 15.7), 4.46 (d, J = 14.8), 4.65 (d, J = 15.7), 4.79 (d, J = 14.8), 6.46 (m), 6.59 (m), 6.85 (m), 7.19-7.70 (m), 7.79 (s), 7.94 (m). MS(ESI): m/z 527 (M+H⁺).

Example 6 Propyl 2-(2-Hydroxyethylamino)-4-phenylquinoline-3-carboxylate (compound 7 of scheme 2)

A mixture of 6 (0.40 g , 1.23 mmol) in absolute ethanol (15 mL) with 2-aminoethanol

(0.30 mL , 4.97 mmol) was refluxed for 15 h. The solvent was then removed under reduced pressure and the residue was diluted with etlryl acetate. The mixture was washed with water, the organic layer was dried over sodium sulfate and concentrated under reduced pressure. Purification of the residue by flash chromatography with petroleum ether-ethyl acetate (6:4) as the eluent gave compound 7 as an orange oil which crystallized on standing

(0.32 g, yield 74%, mp 74-75 °C). ¹H-NMR (CDCl₃): 0.59 (t, J = 7.5, 3H), 0.96-1.14 (m, 2H), 3.71-3.91 (m, 6H), 6.10 (br s,lH), 7.02-7.29 (m, 4H), 7.39-7.54 (m, 4H), 7.65 (d, J=

8.4, IH). MS(ESI): m/z 351 (M+H¹).

Example 7

Propyl l,2-Dihydro-5-phenylimidazo[l,2-a]quinoline-4-carboxylate (compound 8 of scheme 2)

A mixture of 7 (0.18 g, 0.51 mmol) in phosphorous oxychloride (10 mL) was refluxed for 6 h. The excess of POCl₃ was then decomposed with water, and the precipitate was extracted with dichloromethane. The organic phase was dried over sodium sulfate and concentrated under reduced pressure, to give compound 8 as a yellow solid (0.12 g, yield 71%, melting point 158 ⁰C). ¹H-NMR (CDCl₃): 0.66 (t, J= 7.1, 3H), 1.28 (m, 2H), 3.88- 4.16 (m, 6H), 6.72-6.87 (m, 2H), 7.01 (d, J = 7.3, IH), 7.26-7.40 (m, 6H). MS(ESI): m/z 333 (M+H⁺).

Example 8 Propyl 5-Phenylimidazo[l,2-a]quinoline-4-carboxylate (compound 9 of scheme 2)

Compound 8 (0.30 g, 0.90 mmol) was dissolved in DMSO (10 mL) and the resulting mixture was heated at 120 ⁰C for 48 h. The mixture was diluted with water and extracted with dichloromethane, the organic phase was dried over sodium sulfate and concentrated under reduced pressure. Purification of the residue by flash chromatography with CH₂Cl₂- ethyl acetate (7:3) as the eluent gave 9 as an off-white solid (0.19 g, 64%, melting point 117 °C). ¹H-NMR (CDCl₃): 0.71 (t, J= 7.4, 3H), 1.36 (m, 2H), 4.06 (t₅ J= 6.8, 2H), 7.31- 7.69 (m, 8H), 7.71 (s, IH), 7.94 (d, J= 8.4, IH), 8.08 (s, IH). MS(ESI): m/z 331 (MH-H⁺). Example 9

5-Phenylimidazo[l,2-a]quinoline-4-carboxylic acid (compound 10 of scheme 2)

A mixture of 9 (0.14 g, 0.42 mmol) in ethanol (10 mL) with 2N NaOH (4.0 mL) was refluxed for 2 h. The solvent was then removed under reduced pressure and the residue was diluted with water and acidified with 2N HCl (pH = 6). The precipitate was collected by filtration, washed with diethyl ether, and dried under reduced pressure to give 0.10 g of 10 as a white solid melting at 223 °C (yield 83 %). ¹H-NMR (DMSOd₆): 7.35-7.62 (m, 7H), 7.86-7.93 (m, 2H), 8.57 (d, J= 8.4, IH), 8.96 (s, IH). MS(ESI): m/z 289 (M+H*).

Example 10

N- [3,5-Bis(trifluoromethyl)benzyI]-5-phenyimidazo [i ,2-a] quinoline-4-carboxamide (compound Ic of scheme 2)

A mixture of 10 (0.10 g, 0.35 mmol) in ethyl acetate (15 mL) with 2,3,5,6- tetrafluorophenol (0.11 g, 0.66 mmol) and EDC (0.096 g, 0.50 mmol) was stirred at room temperature overnight. The reaction mixture was then concentrated under reduced pressure and the residue was diluted with CHCl₃, washed with 10% sodium bicarbonate solution, dried over sodium sulfate, and evaporated under reduced pressure. The resulting residue was dissolved in DMF (10 mL) and 3,5-bis(trifluoromethyl)benzylamine (0.12 g, 0.49 mmol) was added. After stirring the reaction mixture at room temperature for 1 h, the volatile materials were evaporated under vacuum and the residue was purified by column chromatography with CHCl₃-ethyl acetate (7:3) as eluent to give Ic as a white solid (0.11 g, 61 %, melting point 208 ⁰C). ¹H-NMR (CDCl₃): 4.74 (d, J = 5.9, 2H), 7.28-7.51 (m, 7H), 7.68-7.74 (m, 3H), 7.82 (s, 2H), 7.98 (d, J= 8.3, IH), 8.15 (s, IH), 10.12 (t, J= 6.0, IH). MS(ESI): m/z 514 (!VM-H⁺).

Example 11

N-[3,5-bis(trifluoromethyl)benzyl]-N-methyl-5-phenylimidazo[l,2-a]quinoIine-4- carboxamide (compound Id of scheme 2)

This compound was prepared from 10 (0.35 g, 1.2 mmol), 20 mL of ethyl acetate, 2,3,5,6- tetrafluorophenol (0.40 g, 2.41 mmol), EDC (0.35 g, 1.8 mmol) and N-[3,5- bis(trifluoromethyl)benzyl]methylamine hydrochloride (0.53 g, 1.8 mmol), 0.4 mL of TEA in dry DMF (15 mL) by means of the same procedure described for the synthesis of Ic. The crude product was purified by flash chromatography with CHCl₃-ethyl acetate (7:3) as the eluent to obtain Id as a white solid (0.5O g, yield 79%). An analytical sample melted at 206 °C. The ¹H-NMR spectrum of this amide shows the presence of two different rotamers in equilibrium. For the sake of simplification the integral intensities have not been given. ¹H-NMR (CDCl₃): 2.78 (s), 2.80 (s), 3.93 (d, J= 15.6), 4.49 (d, J = 15.2), 4.70 (d, J= 15.7), 5.08 (d, J= 15.1), 7.21-7.75 (m), 7.98 (m), 8.11 (m). MS(ESI): m/z 528 (M+H⁺).

Example 12

3-(t-Butyl) 4-Ethyl 5-Phenylimidazo[l,5-α]quinoline-3,4-dicarboxylate (compound 12 of scheme 3).

To an ice-cooled solution of 11 (0.60 g, 1.9 mmol) in anhydrous DMF (15 mL) were added t-butyl isocyanoacetate (0.76 g, 5.38 mmol) and potassium t-butoxide (0.65 g, 5.8 mmol) and the resulting mixture was stirred at 0-5 ⁰C for 30'. The reaction mixture was stirred at room temperature for 30' and then heated at 80 °G. for 10 h. The final mixture was neutralized with glacial acetic acid, poured into crushed ice and extracted with ethyl acetate. The combined extracts were dried over sodium sulfate and concentrated under reduced pressure. The residue was purified by washing with diethyl ether to give 0.65 g of

12 as a yellow solid (yield 82%). An analytical sample melted at 159-161 °C. ¹H-NMR (CDCl₃): 1.02 (t, J= 7.0, 3H), 1.63 (s, 9H), 4.12 (q, J= 7.0, 2H), 7.33-7.48 (m, 7H), 7.66 (m, IH), 8.07 (d, J= 8.3, IH), 8.68 (s, IH). MS(ESI): m/z 439 (M+Na⁺).

Example 13

4-(Ethoxycarbonyl)-5-phenylimidazo[l,5-α]quinoline-3-carboxylic Acid (compound

13 of scheme 3) A mixture of compound 12 (0.60 g, 1.44 mmol) in formic acid (15 ml) was heated at 50 °C for 3 h. The reaction mixture was then concentrated under reduced pressure while the remaining formic acid was azeotropically removed with toluene. The residue was purified by washing with ethanol to give 0.50 g of 13 as an off-white solid (yield 96%). An analytical sample melted at 245-247 °C. ¹H-NMR (DMSOd₆): 0.87 (t, J= 6.8, 3H), 3.91 (q, J = 6.9, 2H), 7.04-7.83 (m, 8H), 8.59 (d, J = 8.3,^' IH), 9.36 (s, IH), 12.38 (s, IH). MS(ESI, negative ions): m/z 359 (M-H⁺).

Example 14 Ethyl 5-Phenylimidazo[l,5-α]quinoline-4-carboxyIate (compound 14 of scheme 3)

Compound 13 (0.20 g, 0.55 rnmol) was heated without solvent at 190-200 °C until the end of CO₂ bubbling. The cooled residue was dissolved in ethyl acetate (30 mL), washed with water, dried over sodium sulfate and concentrated under reduced pressure. Purification of the residue by flash chromatography with ethyl acetate as the eluent gave 14 as a yellow solid (0.075 g, 43%, melting point 113-114 ⁰C). ¹H-NMR (CDCl₃): 0.95 (t, J= 6.9, 3H), 4.09 (q, J= 6.9, 2H), 7.27-7.48 (m, 7H), 7.59 (m, ,1H), 7.72 (s, IH), 8.01 (d, J = 8.1, IH), 8.69 (s, IH). MS(ESI): m/z 317 (M+H⁺).

Example 15

5-Phenylimidazo[l,5-a]quinoline-4-carboxylic acid (compound 15 of scheme 3)

A mixture of 14 (0.20 g, 0.63 mmol) in ethanol (8.0 mL) with 2N NaOH (4.0 mL) was refluxed for 2 h. The reaction mixture was acidified with 2N HCl (pH = 6) and the solvent was removed under reduced pressure. The residue was washed with ethanol and the organic solution was evaporated under reduced pressure to give 0.12 g of 15 as a brown solid (yield 66 %, mp >300 °C). ¹H-NMR (DMSO-d₆): 7.18-7.54 (m, 9H), 8.34 (d, J= 8.0, IH), 9.02 (s, IH). MS(ESI): m/z 289 (M+H⁺).

Example 16 N-[3,5-Bis(trifluoromethyl)benzyl]-5-phenyIimidazb[l,5-α]quinoline-4-carboxamide (compound Ie of scheme 3) ^l

A solution of HOBt (0.058 g, 0.43 mmol) in dry dichloromethane (10 mL) was added to an ice-cooled mixture of 15 (0.105 g, 0.36 mmol) and 3,5-bis(trifluoromethyl)benzylamine (0.105 g, 0.43 mmol) in the same solvent (10 mL). After stirring at 0-5 ⁰C for 10 min, a solution of DCC (0.112 g, 0.54 mmol) in dichloromethane (10 mL) was added dropwise, and the resulting mixture was stirred at room temperature for 20 h. The precipitate was filtered-off and the filtrate was washed in sequence with water and brine, then dried and evaporated under reduced pressure. The residue was purified by column chromatography with n-hexane-ethyl acetate (2:8) as eluent to give Ie as a white solid (0.12 g, yield 65 %). An analytical sample melted at 191 °C. ¹H-NMR (CDCl₃): 4.43 (d, J= 6.0, 2H), 5.90 (t, J = 5.9, IH), 7.33 (m, 7H), 7.50 (s, 2H), 7.61 (m, IH), 7.68 (s, IH), 7.77 (s, IH), 8.02 (d, J= 8.1, IH), 8.78 (s, IH). MS(ESl): m/z 514 (M+H⁺). Example 17

N-[3,5-Bis(trifluoromethyl)benzyl]-N-methyI-5-phenylimidazo[l,5-α]quinoline-4- carboxamide (compound If of scheme 3)

This compound was prepared from 15 (0.20 g, 0.69 mmol), 15 mL of dry dichloromethane, HOBt (0.113 g, 0.84 mmol), DCC (0.215 g, 1.04 mmol), 0.50 mL of TEA, and N-[3,5- bis(trifluoromethyl)benzyl]methylamine hydrochloride (0.30 g, 1.02 mmol) by means of the same procedure described for the synthesis of Ie. The crude product was purified by flash chromatography with n-hexane-ethyl acetate (3:7) as the eluent to obtain If as a white solid (0.22 g, yield 60%, melting point 175 ⁰C). The ¹H-NMR spectrum of this amide shows the presence of two different rotamers in equilibrium. For the sake of simplification the integral intensities have not been given. ¹H-NMR (CDCl₃): 2.73 (s), 2.77 (s), 4.09 (d, J = 16.0), 4.32 (d, J = 14.7), 4.57 (d, J= 16.0), 4.95 (d, J = 14.7), 7.20-7.71 (m), 7.79 (s), 8.03 (d, J = 8.3), 8.72 (s). MS(ESI): m/z 528 (M+H⁺).

Example 18

N-[3,5-Bis(trifluoromethyl)benzyl]-l,2-dihydro-2-oxo-4-phenylquinoline-3- carboxamide (compound 17a of scheme 4)

A mixture of acid 16 (0.10 g, 0.38 mmol) in thionyl chloride (5 mL) was refluxed for 3 h. The thionyl chloride excess was azeotropically removed with toluene and the residue was immediately dissolved in dichloromethane (15 mL). To the resulting solution 3,5- bis(trifluoromethyl)benzylamine (0.14 g, 0.57 mmol) and 0.30 mL of TEA were added and the reaction mixture was refluxed for 4 h. The final mixture was diluted with CH₂Cl₂ (15 mL), washed with water, dried over sodium sulfate, and concentrated under reduced pressure. The residue was purified by washing with diethyl ether to give 0.125 g of pure 17a as a white solid (yield 67%). Melting point 251 ⁰C, literature (EP0585913) mp 251- 252 ⁰C. ¹H-NMR (CDCl₃): 4.59 (d, J= 6.0, 2H), 7.09-7.54 (m, 10H), 7.71 (m, 2H), 8.29 (t, J= 5.9, IH)₅ 11.30 (br s, IH). MS(ESI): m/z 513 (M+Na⁺).

Example 19 N-[3,5-Bis(trifluoromethyl)benzyl]-l,2-dihydro-N-methyl-2-oxo-4-phenylquinolme-3- carboxamide (compound 17b of scheme 4)

A mixture of acid 16 (0.5O g, 1.88 mmol) in thionyl chloride (8 mL) was refluxed for 3h. The thionyl chloride excess was azeotropically removed with toluene and the residue was immediately dissolved in dichloromethane (20 mL). To the resulting solution 3,5- bis(trifluoromethyl)benzylamine hydrochloride (0.60 g, 2.04 mmol) and 0.5 mL of TEA were added and the reaction mixture was refluxed for 4 h. The final mixture was diluted with CH₂Cl₂ (20 mL), washed with water, dried over sodium sulfate, and concentrated under reduced pressure. Crude compound 17b was purified by washing with diethyl ether to obtain a white solid (0.60 g, yield 63%). Melting point 263-264 ⁰C, literature (EP0585913) mp 262-264 °C. The ¹H-NMR spectrum of this amide shows the presence of two different rotamers in equilibrium. For the sake of simplification the integral intensities have not been given. ¹H-NMR (CDCl₃): 2.73 (s), 2.87 (s), 4.08 (d, J = 16.2), 4.60 (d, J = 15.2), 4.70-4.82 (m), 7.09-7.77 (m), 12.43 (br s). MS(ESI): m/z 527 (M+Na⁺).

Example 20

N-[3,5-Bis(trifluoromethyl)benzyl]-2-chloro-4-phenylquinoline-3-carboxamide (compound 18a of scheme 4) A mixture of 17a (0.10 g , 0.20 mmol) in phosphorus oxychloride (10 mL) was refluxed for 4 h. The excess of POCl₃ was decomposed with ice-water, and the precipitate was extracted with dichloromethane. The combined extracts were dried over sodium sulfate and concentrated under reduced pressure to give a crude product which, after purification by flash chromatography CH₂Cl₂-ethyl acetate (9:1) afforded 18a as a white solid (0.085 g, yield 84 %, mp 172 °C). ¹H-NMR (CDCl₃): 4.41 (d, J = 6.0, 2H), 6.10 (t, J = 5.9, IH), 7.26-7.53 (m, 9H), 7.73 (m, 2H), 8.01 (d, J= 8.4, IH). MS(ESI): m/z 509 (MH-H⁺).

Example 21

N-[3,5-Bis(trifluoromethyl)benzyl]-2-chloro-N-methyI-4-phenylquinoline-3- carboxamide (compound 18b of scheme 4)

This compound was prepared from 17b (0.56 g, 1.1 mmol) and phosphorus oxychloride (10 mL) by the same procedure described for the synthesis of 18a. This compound was purified by flash chromatography with n-hexane-ethyl acetate (8:2) as the eluent to obtain 18b as a white solid (0.51 g, yield 89%); melting point 148 ⁰C₅ literature (EP0585913) mp 147-148 °C. The ¹H-NMR spectrum of this amide shows the presence of two different rotamers in equilibrium. For the sake of simplification the integral intensities have not been given. ¹H-NMR (CDCl₃): 2.70 (s), 2.75 (s), 4.04 (d, J= 15.9), 4.48 (d, J= 15.6), 4.53 (d, J = 14.9), 4.69 (d, J= 14.9), 7.21 (m), 7.34-7.65 (m), 7.77 (m), 8.09 (d, J= 8.4). MS(ESI): m/z 523 (M+H⁺).

Example 22 N-[3,5-Bis(trifluoromethyl)benzyl]-2-hydrazino-4-phenylquinoline-3-carboxamide (compound 19a of scheme 4)

To a solution of 18a (0.48 g, 0.94 mmol) in ethanol (15 niL) was added an excess of hydrazine hydrate (200 μL, 4.1 mmol) and the resulting mixture was refluxed for 3 h. The solvent was then removed under reduced pressure and the residue was diluted with CH₂Cl₂ (20 mL); the organic phase was washed with water, dried over sodium sulfate and concentrated under reduced pressure to obtain 19a as a brown solid (0.40 g, 84%, mp 163 ⁰C). ¹H-NMR (CDCl₃): 4.30 (d, J = 6.0, 2H), 5.67 (t, J= 6.0, IH), 7.11-7.61 (m, 10H), 7.77 (m, 2H). MS(ESI): m/z 505 (M+H⁺).

Example 23

N-[3,5-Bis(trifluoromethyl)benzyl]-2-hydrazino-N-methyl-4-phenylquinoline-3- carboxamide (compound 19b of scheme 4)

The title compound was prepared from 18b (0.48 g, 0.92 mmol), 15 mL of ethanol, and hydrazine hydrate (180 μL, 3.7 mmol) by the same procedure described for the synthesis of 19a to obtain 19b as an orange oil (0.40 g, yield 84%). The oil obtained was used in the next step of the synthesis without purification. MS (ESI): m/z 519 (M+H⁺).

Example 24

N-[3,5-Bis(trifIuoromethyl)benzyl]-5-phenyl[l,2,4]triazolo[4,3-β]quinoline-4- carboxamide (compound Ig of scheme 4)

A mixture of 19a (0.36 g, 0.71 mmol) in formic acid (20 mL) was heated at 80 ⁰C under argon for 4 h. The formic acid excess was removed under reduced pressure and the residue was dissolved in CHCl₃ and washed with water. The organic layer was dried over sodium sulfate and concentrated under reduced pressure. Purification of the residue by flash chromatography with ethyl acetate-TEA (9:1) as the eluent gave pure Ig as a white solid (0.35 g, yield 96 %). An analytical sample melted at 226 ⁰C. ¹H-NMR (CDCl₃): 4.73 (d, J = 6.0, 2H), 7.29 (m, 2H), 7.49 (m, 6H), 7.76 (m, 3H), 8.06 (d, J= 8.3, IH), 9.36 (s, IH), 9.82 (t, J= 5.8, IH). MS(ESI): m/z 515 (M+H⁺). Example 25

N-[3,5-Bis(trifluoromethyl)benzyl]-N-methyl-5-phenyl[l,2,4]triazolo[4,3-fl]quinoline- 4-carboxamide (compound Ih of scheme 4) This compound was prepared from 19b (0.36 g, 0.69 mmol) by the same procedure described for the synthesis of Ig and was purified by flash chromatography with ethyl acetate-TEA (9:1) as the eluent to obtain Ih as a yellow oil which crystallized from diethyl ether (0.35 g, yield 96%). An analytical sample melted at 224 ⁰C. The ¹H-NMR spectrum of this amide shows the presence of two different rotamers in equilibrium. For the sake of simplification the integral intensities have not been given. ¹H-NMR (CDCl₃): 2.85 (s), 4.29 (d, J = 15.2), 4.63 (d, J = 16.0), 5.27 (d, J= 15.0), 7.16-7.79 (m), 8.07 (m), 9.36 (s), 9.39 (s). MS(ESI): m/z 529 (M+H⁺).

Example 26 Ethyl 5-Phenyltetrazolo [1 ,5-α] quinoline-4-carboxylate (compound 21 a of scheme 5)

A mixture of 11 (0.80 g, 2.57 mmol) in anhydrous DMF (15 mL) with sodium azide (0.33 g, 5.1 mmol) was heated at 80 ⁰C for 36 h. The solvent was then removed under reduced pressure and the residue was diluted with ethyl acetate (20 mL). The organic phase was washed with water, dried over sodium sulfate and concentrated under reduced pressure. The residue was purified by recrystallization from diethyl ether to give 21a as a white solid (0.52 g, yield 64%, mp 154-156 ⁰C). ¹H-NMR^' (CDCl₃): 1.03 (t, J= 7.0, 3H), 4.21 (q, J= 7.0, 2H), 7.36-7.69 (m, 7H), 7.91 (m, IH), 8.77 (d, J= 8.3, IH). MS(ESI): m/z 319 (M+H⁺).

Example 27

Ethyl 5-(4-Methylphenyl)tetrazolo[l,5-α]quinoline-4-carboxylate (compound 21b of scheme 5)

The title compound was prepared from 20b (0.70 g, 2.15 mmol) by the same procedure described for the synthesis of 21a to obtain 21b (0.43 g, yield 60%) as a white solid melting at 177 ⁰C. ¹H-NMR (CDCl₃): 1.08 (t, J= 6.9, 3H), 2.48 (s, 3H), 4.25 (q, J= 7.0, 2H), 7.32 (m, 4H), 7.59-7.74 (m, 2H), 7.92 (m, IH), 8.78 (d, J= 8.4, IH). MS(ESl): m/z 333 (M+H⁺). Example 28

Ethyl 5-(4-Fluorophenyl)tetrazolo[l,5-β]quinoline-4-carboxylate (compound 21c of scheme 5)

The title compound was prepared from 20c (0.80 g, 2.43 mmol) by the same procedure described for the synthesis of 21a to obtain 21c (0.70 g, yield 86%) as a white solid. An analytical sample melted at 173 ⁰C. ¹H-NMR (CDCl₃): 1.09 (t, J= 7.0, 3H), 4.24 (q, J = 7.0, 2H), 7.19-7.42 (m, 4H), 7.64 (m, 2H), 7.92 (m, IH), 8.76 (d, J = 8.2, IH). MS(ESI): m/z 337 (M+H⁺).

Example 29

5-Phenyltetrazolo[l,5-α]quinoline-4-carboxylic Acid (compound 22a of scheme 5)

A mixture of 21a (0.20 g, 0.63 mmol) in ethanol (10 mL) with 2N NaOH (4.0 mL) was refluxed for 3 h. The solvent was then removed under reduced pressure, and the residue was diluted with water and acidified with 2N HCl. The precipitate was collected by filtration, washed with rø-hexane and dried under reduced pressure to give 0.17 g of 22a as a white solid (yield 93 %). An analytical sample melted at 256-258 °C. ¹H-NMR (DMSO- d₆): 7.42-7.53 (m, 6H)₅ 7.71 (m, IH), 7.97 (m, IH), 8.68 (d, J= 8.3, IH), 13.81 (br s, IH). MS(ESI): m/z 313 (M+Na⁺).

Example 30

5-(4-Methylphenyl)tetrazolo[l,5-α]quinoline-4-carboxylic Acid (compound 22b of scheme 5)

The title compound was prepared from 21b (0.13 g, 0.40 mmol) by the same procedure described for the synthesis of 22a to obtain 22b as a white solid (0.10 g, yield 83%). An analytical sample melted at 265 °C. ¹H-NMR (DMSO-d₆): 2.40 (s, 3H), 7.34 (m, 4H), 7.57 (m, IH), 7.74 (m, IH), 8.00 (m, IH), 8.69 (d, J= 8.4, IH), 13.80 (br s, IH). MS(ESI): m/z 327 (MH-Na⁺).

Example 31 5-(4-Fluorophenyl)tetrazolo[l,5-α]quinoIine-4-carboxylic Acid (compound 22c of scheme 5)

The title compound was prepared from 21c (0.40 g, 1.19 mmol) by the same procedure described for the synthesis of 22a to obtain 22c as a white solid (0.35 g, yield 95%). An analytical sample melted at 267 °C. ¹H-NMR (DMSOd₆): 7.36-7.56 (m, 5H)₃ 7.75 (m, IH), 8.02 (m, IH), 8.70 (d, J= 8.2, IH). MS(ESI): m/z 331 (M+Na⁺).

Example 32 N-[3,5-Bis(trifluoromethyl)benzyl]-5-phenyltetrazolo[l,5-α]quinolme-4-carboxamide (compound Ii of scheme 5)

The title compound was prepared from acid 22a (0.030 g, 0.10 mmol) and 3,5- bis(trifluoromethyl)benzylamine (0.050 g, 0.20 mmol) by the same procedure described for the synthesis of compound 17a and was obtained as a white solid (0.030 g, yield 58%, mp 193-195 °C). ¹H-NMR (CDCl₃): 4.75 (d, J = 5.9, 2H), 7.31 (m, 2H), 7.51-7.69 (m, 6H), 7.75 (s, 2H), 7.96 (m, IH), 8.79 (d, J = 8.3, IH), 9.09 (t, J= 6.0, IH). MS(ESI): m/z 516

Example 33 N-[3,5-Bis(trifluoromethyl)benzyl]-N-methyl-5-phenyItetrazolo[l,5-fl]quinoline-4- carboxamide (compound Ij of scheme 5)

The title compound was prepared from acid 22a (0.050 g, 0.17 mmol) and N-[3,5- bis(rrifluoromethyl)benzyl]methylamine hydrochloride (0.10 g, 0.34 mmol) by the same procedure described for the synthesis of compound 17b and was obtained as a white solid (0.071 g, yield 79%, mp 222-224 ⁰C). The ¹H-NMR spectrum of this amide shows the presence of two different rotamers in equilibrium. For the sake of simplification the integral intensities have not been given. ¹H-NMR (CDCl₃): 2.80 (s), 2.86 (s), 4.19 (d, J = 15.9), 4.35 (d, J = 15.0), 4.57 (d, J = 16.0), 5.19 (d, J = 15.0), 7.18-7.95 (m), 8.78 (m). MS(ESI): m/z 530 (M+H⁺).

Example 34

N-[3,5-Bis(trifluoromethyl)benzyl]-5-(4-methyIphenyl)tetrazolo[l,5-β]quinoline-4- carboxamide (compound Ik of scheme 5)

The title compound was prepared from acid 22b (0.090 g, 0.30 mmol) and 3,5- bis(trifluoromethyl)benzylamine (0.14 g, 0.58 mmol) by the same procedure described for the synthesis of compound 17a and was obtained_^as a white solid (0.12 g, yield 76%). An analytical sample of Ik melted at 227 °C. ¹H-NMR (CDCl₃): 2.46 (s, 3H), 4.76 (d, J= 6.0, 2H), 7.18-7.35 (m, 4H), 7.62-7.77 (m, 5H), 7.94 (m, IH), 8.75 (d, J= 8.3, IH)₅ 8.99 (t, J= 5.9, IH). MS(ESI): m/z 530 (IVH-H⁺).

Example 35 - N-[3,5-Bis(trifluoromethyl)benzyl]-N-methyl-5-(4-methylphenyl)tetrazolo[l,5- α]quinoline-4-carboxamide (compound 11 of scheme 5)

The title compound was prepared from acid 22b (0.090 g, 0.30 mmol) and N-[3,5- bis(Mfluoromethyl)benzyl]methylamine hydrochloride (0.18 g, 0.61 mmol) by the same procedure described for the synthesis of compound 17b and was obtained as a white solid (0.13 g, yield 80%). An analytical sample of 11 melted at 183 °C. The ¹H-NMR spectrum of this amide shows the presence of two different rotamers in equilibrium. For the sake of simplification the integral intensities have not been given. ¹H-NMR (CDCl₃): 2.41 (s), 2.49 (s), 2.82 (s), 2.89 (s), 4.21 (d, J= 16.0), 4.40 (d, J= 15.1), 4.57 (d, J= 15.9), 5.21 (d, J = 15.1), 7.10 (m), 7.26 (m), 7.40-7.73 (m), 7.80_, (s), 7.90 (m), 8.77 (m). MS(ESI): m/z 544 (M+H⁺).

Example 36

N-[3,5-Bis(trifluoromethyl)benzyl]-5-(4-fluorophenyl)tetrazolo[l,5-α]quinoline-4- carboxamide (compound Im of scheme 5) The title compound was prepared from acid 22c (0.15 g, 0.49 mmol) and 3,5- bis(trifluoromethyl)benzylamine (0.24 g, 0.99 mmol) by the same procedure described for the synthesis of compound 17a and was obtained as a white solid (0.20 g, yield 77%). An analytical sample of Im was purified by flash chromatography with dichloromethane-ethyl acetate (9:1) as the eluent (mp 232-233 ⁰C). ¹H-NMR (CDCl₃): 4.76 (d, J= 6.0, 2H), 7.26 (m, 4H), 7.55-7.78 (m, 5H), 7.96 (t, J= 7.4, IH), 8.77 (d, J= 8.3, IH), 9.21 (t, J = 6.0, IH). MS(ESI): m/z 534 (M+H⁺).

Example 37

N-[3,5-Bis(trifluoromethyl)benzyl]-5-(4-fluorophenyl)-N-methyltetrazolo[l,5- α]quinoIine-4-carboxamide (compound In of scheme 5)

The title compound was prepared from acid 22c (0.15 g, 0.49 mmol) and N-[3,5- bis(trifluoromethyl)benzyl]methylamine hydrochloride (0.29 g, 0.99 mmol) by the same procedure described for the synthesis of compound 17b and was obtained as a white solid (0.19 g, yield 71%). An analytical sample of In was purified by flash chromatography with dichloromethane-ethyl acetate (9:1) as the eluent (mp 252 °C). The ¹H-NMR spectrum of this amide shows the presence of two different rotamers in equilibrium. For the sake of simplification the integral intensities have not been given. ¹H-NMR (CDCl₃): 2.84 (s), 2.91 (s), 4.22 (d, J = 15.9), 4.42 (d, J = 15.0), 4.58 (d, J = 15.9), 5.16 (d, J = 15.0), 7.07-7.36 (m), 7.53-7.76 (m), 7.82 (s), 7.93 (m), 8.80 (m). MS(ESI): m/z 570 (M+Na⁺).

Example 38

N-(2-Methoxybenzyl)-5-phenyltetrazolo[l,5-α]quinoline-4-carboxamide (compound Io of scheme 5)

The title compound was prepared from acid 22a (0.20 g, 0.69 mmol) and 2- methoxybenzylamine (0.18 mL, 1.38 mmol) by the same procedure described for the synthesis of compound 17a, and was obtained as a white solid (0.22 g, yield 78%). An analytical sample of Io melted at 222 °C. ¹H-NMR (CDCl₃): 3.88 (s, 3H), 4.58 (d, J= 5.8, 2H), 6.86 (m, 2H), 7.18-7.32 (m, 4H), 7.45-7.59 (m, 5H), 7.89 (m, IH), 8.47 (t, J = 5.9, IH), 8.74 (d, J= 8.2, IH). MS(ESI): m/z 410 (M+H⁴).

Example 39

N-(3,5-Dimethoxybenzyl)-5-phenyltetrazolo[l,5-fl]qumoline-4-carboxamide (compound Ip of scheme 5)

The title compound was prepared from acid 22a (0.20 g, 0.69 mmol) and 3,5- dimethoxybenzylamine (0.23 g, 1.38 mmol) by the same procedure described for the synthesis of compound 17a and was obtained as a white solid (0.28 g, yield 92%). An analytical sample of Ip melted at 215 °C. ¹H-NMR (CDCl₃): 3.78 (s, 6H), 4.54 (d, J= 5.6, 2H), 6.35 (t, J= 1.9, IH), 6.48 (d, J= 1.8, 2H), 7.34 (m, 2H), 7.52-7.66 (m, 5H), 7.92 (m, IH), 8.44 (t, J= 5.6, IH), 8.76 (d, J= 8.2, IH). MS(ESI): m/z 440 (M+H⁺).

Pharmacological activity

Binding to human native NKl receptors The compounds of the invention were tested for their activity in inhibiting the specific binding of [¹²⁵I]BH-SP (100 pM) to human native NK₁ receptor expressed in astrocytoma UCIlMG cells as compared with unlabeled SP and reference nonpeptide antagonist L- 703,606. The binding studies were performed according to the procedure recommended by the manufacturer of the membranes (Amersham Pharmacia Biotech, Amersham, U.K.). The membranes, still in the packaging 50 mM TRIS-HCl buffer (pH 7.4) containing 10% glycerol and 1% BSA, were diluted 1:15 with incubation buffer containing: 40 mM Hepes, 5 mM MgCl₂, 1 mM EDTA, 0.5% BSA, 0.025% bacitracin, and 25 mM phosphoramidon. Aliquots of 150 mL of the suspension at a protein concentration of 60 mg/mL were used for the binding reactions.

Saturation binding experiments were first performed in order to determine the suitable concentration of the radioligand to be used in competition assays. Thus, human astrocytoma UCIlMG cell membranes (150 mL) were incubated at 25° C for 45 min with increasing concentrations (20, 50, 80, 100, 120, 200, 300, 400 pM) of [¹²⁵I]BH-SP (¹²⁵I- substance P labelled with the Bolton and Hunter reagent, s. a. 74 TBq/mmol, Amersham Pharmacia Biotech, Amersham, U.K.) in a total volume of 200 mL incubation buffer. The non-specific binding was defined in all assays by running parallel samples added with unlabelled SP at a final concentration of 2 mM. In order to obtain the specific binding the average blanks were subtracted from the total binding. The specific binding of [ I] SP to these human NK₁ receptors in the 20-400 pM range can be described by a single component (B = B_Max x CZ(Ku + C)) where K_M = 120 pM and B_Max = 0.09 pM/mg of proteins. In competition studies membranes were incubated with [¹²⁵I]BH-SP (100 pM final concentration) and increasing concentrations of the ligands from 10^"13 M to 10^"6 M (additional concentration points were used in the case of compounds showing very high affinities). The non-specific binding was defined with unlabelled SP at a final concentration of 2 mM. Incubations were terminated by rapid filtration over Whatman GF/C filters (presoaked in 0.3% polyethylenimine and air-dried). After washing three times with 50 mM TRIS-HCl buffer (pH 7.4), the radioactivity which remained on the filter was measured with γ-counter (Cobra, Packard Bioscience Company, Meriden, CT). The binding of [¹²⁵I] SP was confirmed to be due to NK₁ receptors because it was completely displaced by the nonpeptide antagonist to the human NK₁ receptors L-703,606, with an IC₅Q of 1.6 nM. Results are reported in Table 2. Table 2. Binding affinity of compounds of formula 1 for human native NK₁ receptors.

Compd X-Y-Z Ri R₂ R₃ ^• R₄ Native IC₅₀ (nM)

Ia =CH-CH=CH- H 3-CF₃ 5-CF₃ H

Ib =CH-CH=CH- CH₃ 3-CF₃ 5-CF₃ H

Ic =N-CH=CH- H 3-CF₃ 5-CF₃ H

Id =N-CH=CH- CH₃ 3-CF₃ 5-CF₃ H

Ie =CH-N=CH- H 3-CF₃ 5-CF₃ H 0.0011

If =CH-N=CH- CH₃ 3-CF₃ 5-CF₃ H 15

Ig =N-N=CH- H 3-CF₃ 5-CF₃ H 229

Ih =N-N=CH- CH₃ 3-CF₃ 5-CF₃ H

Ii =N-N=N- H 3-CF₃ 5-CF₃ H 0.0014

Ij =N-N=N- CH₃ 3-CF₃ 5-CF₃ H 15

Ik =N-N=N- H 3-CF₃ 5-CF₃ CH₃

11 =N-N=N- CH₃ 3-CF₃ ¹ 5-CF₃ . CH₃

Im =N-N=N- H 3-CF₃ 5-CF₃ F

In =N-N=N- CH₃ 3-CF₃ 5-CF₃ F

The compounds of the present invention show high NK₁ receptor affinity; for example, some secondary amide derivatives display IC₅₀ values for native NKl receptor in the picomolar range (Table 2), while the tertiary amide derivatives lf,j show inhibition constant values in the nanomolar range.

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Claims

1. Compound of general formula 1:

wherein

X, Y, Z are CH or N; R₁ is H, CH₃ or a linear alkyl group unsubstituted or substituted;

R₄ represents an hydrogen, an halogen, a linear alkyl group unsubstituted or substituted or an hydroxyl group; and pharmaceutically acceptable salts thereof produced from inorganic or organic acids.

2. The compound according to claim 1 wherein R₂ and R₃ are a trifluoromethyl or a methoxy group.

3. The compound according to claim 1 wherein R₄ is F or CH₃.

4. The compound according to claim 1 being N-[3,5-Bis(trifluoromethyl)benzyl]-5- phenylpyrrolo[ 1 ,2-β]quinoline-4-carboxamide.

5. The compound according to claim 1 being N-[3,5-Bis(trifluoromethyl)benzyl]-N- methyl-5-phenylpyrrolo[l,2-α]quinoline-4-carboxamide.

6. The compound according to claim 1 being N-[3,5-Bis(trifluoromethyl)benzyl]-5- phenylimidazo[l,2-α]quinolme-4-carboxamide.

7. The compound according to claim 1 being N-[3,5-bis(trifluoromethyl)benzyl]-N-methyl- 5-phenylimidazo[ 1 ,2-α]qumoline-4-carboxamide.

8. Compound according to claim 1 being N-[3,5-Bis(trifluoromethyl)benzyl]-5- phenylimidazo[l,5-α]quinoline-4-carboxamide.

9. The compound according to claim 1 being N-[3,5-Bis(trifluoromethyl)benzyl]-N- methyl-5-phenylrniidazo[l,5-a]qumolme-4-carboxamide.

10. The compound according to claim 1 being N-[3,5-Bis(trifluoromethyl)benzyl]-5- phenyl[l,2,4]triazolo[4,3-α]quinoline-4-carboxarnide.

11. The compound according to claim 1 being N-[3,5-Bis(trifluoromethyl)benzyl]-N- methyl-5-phenyl[l,2,4]triazolo[4,3-α]quinoline-4-carboxamide.

12. The compound according to claim 1 being N-[3,5-Bis(trifluoromethyl)benzyl]-5- phenyltetrazolo[l,5-α]quinoline-4-carboxamide.

13. The compound according to claim 1 being N-[3,5-Bis(trifluoromethyl)benzyl]-N- methyl-5-phenyltetrazolo[ 1 ,5-α]quinoline-4-carboxamide.

14. The compound according to claim 1 being N-[3,5-Bis(trifluoromethyl)benzyl]-5-(4- methylphenyl)tetrazolo[l,5-α]quinoline-4-carboxamide.

15. The compound according to claim 1 being N-[3,5-Bis(trifluoromethyl)benzyl]-N- methyl-5-(4-methylphenyl)tetrazolo[l,5-β]quinoline-4-carboxamide.

16. The compound according to claim 1 being N-[3,5-Bis(trifluoromethyl)benzyl]-5-(4- fluorophenyl)tetrazolo [ 1 ,5 -α] quinoline-4-carboxamide.

17. The compound according to claim 1 being N-[3,5-Bis(trifluoromethyl)benzyl]-5-(4- fluorophenyl)-N-methyltetrazolo[ 1 ,5-«]quinoline-4-carboxamide.

18. The compound according to claim 1 being N-(2-methoxybenzyl)-5- phenyltetrazolo[ 1 ,5-α]quinolme-4-carboxamide.

19. The compound according to claim 1 being N-(3,5-dimethoxybenzyl)-5- phenyltetrazolo[ 1 ,5-α]quinoline-4-carboxamide.

20. The compound according to any previous claims for medical use.

21. Pharmaceutical composition comprising in an acceptable and effective amount the compound according to claims 1-19 and suitable excipients.

22. Method for the treatment of spontaneous or post-operative or cytostatic therapy- induced nausea and/or vomiting comprising the administration of the compound or a pharmaceutically acceptable salt thereof according to claims 1-19.

23. Method for the treatment of a pathological condition of the CNS connected with an imbalance in the physiological neuronal level of substance P comprising the administration of the compound or a pharmaceutically acceptable salt thereof according to claims 1-19.

24. Method according to claim 23 wherein the pathological condition is selected from the group consisting of anxiety, panic attack, psychosis, depression, Alzheimer's disease, Parkinson's disease, multiple sclerosis.

25. Method for the treatment of a disorder of the gastrointestinal system comprising the administration of the compound or a pharmaceutically acceptable salt thereof according to claims 1-19.

26. Method according to claim 25 wherein the disorder is selected from the group consisting of functional bowel diseases such as irritable bowel syndrome (IBS).

27. Method for the treatment of angiogenesis-dependent diseases comprising the administration of the compound or a pharmaceutically acceptable salt thereof according to claims 1-19.

28. Method for the preparation of a compound according to claim 1 comprising the step of transforming an acid of formula 23 into an amide derivative with a suitable amine, at least a suitable activating agent and at least a suitable solvent.

29. Method according to claim 28 wherein the suitable solvent is CH₂Cl₂, TEA, EtOAc, DMF, the suitable activating agent is dicyclohexylcarbodiimide (DCC), 1- hydroxybenzotriazole (HOBt), 2,3,5,6-tetrafluorophenol (TFP-OH), EDC, or thionyl chloride.

30. Method for the preparation of the intermediate acid compound of formula 5 comprising the following steps:

a) reacting commercially available 2-benzylaniline (2, Scheme 1) with 2,5- dimethoxytetrahydrofuran in glacial acetic acid to give intermediate 3 (Scheme 1); b) reacting 3 with ethyl oxalylchloride in a suitable solvent or a solvent mixture to give intermediate 4 (scheme 1); c) cyclizing 4 in the presence of a suitable base in a suitable solvent to obtain the carboxylic acid derivate 5.

31. Method according to claim 30 wherein the suitable solvent in b) is benzene, the suitable base in c) is sodium hydride and the suitable solvent in c) is anhydrous DMF.

32. Method for the preparation of an intermediate acid compound of formula 10 comprising the following steps:

10

a) cyclizing hydroxyethylamino intermediate 7 into the corresponding imidazo[l,2- a]quinoline derivative 8 with a suitable dehydrating agent (scheme 2); b) oxidating 8 with a suitable oxidizing agent to give an ester 9 (scheme 2); c) hydrolysing the ester 9 in the presence of a suitable base to obtain the carboxylic acid derivate 10.

33. Method according to claim 32 wherein the suitable dehydrating agent in a) is phosphorous oxychloride, the suitable oxidizing agent in b) is DMSO and the suitable base in c) is sodium hydroxide.

34. Method for the preparation of an intermediate acid compound of formula 15 comprising the following steps:

a) reacting 2-chloroquinoline derivative 11 (scheme 3) with t-butyl isocyanoacetate in the presence of a suitable base in a suitable solvent to obtain the imidazo[l,5- ajquinoline derivative 12 (scheme 3); b) cleaving 12 with a suitable acid to give derivative 13 (scheme 3); c) decarboxylating acid 13 into ester 14 (scheme 3). d) hydrolysing ester 14 in the presence of a suitable base to obtain the carboxylic acid derivate 15. _t

35. Method according to claim 33 wherein the suitable base in a) is t-BuOK, the suitable solvent in a) is anhydrous DMF, the suitable acid in b) is formic acid and the suitable base in d) is sodium hydroxide.