WO2005115987A1

WO2005115987A1 - Therapeutic compounds: pyridine n oxide scaffold

Info

Publication number: WO2005115987A1
Application number: PCT/SE2005/000752
Authority: WO
Inventors: Ziping Liu; Christopher Walpole; Zhong-Yong Wei; Hua Yang
Original assignee: Astrazeneca Ab
Priority date: 2004-05-25
Filing date: 2005-05-20
Publication date: 2005-12-08
Also published as: EP1756061A1; US20070219254A1; CN1956959A; SE0401343D0; JP2008500335A

Abstract

Compounds of formula I or pharmaceutically acceptable salts thereof: wherein R1, R2, R3, R4, m and n are as defined in the specification as well as salts and pharmaceutical compositions including the compounds are prepared. They are useful in therapy, in particular in the management of pain.

Description

Therapeutic Compounds: Pyridine N Oxide Scaffold.

BACKGROUND OF THE INVENTION 1. Field of the invention The invention is related to therapeutic compounds, pharmaceutical compositions containing these compounds, manufacturing processes thereof and uses thereof. Particularly, the present invention is related to compounds that may be effective in treating pain, cancer, multiple sclerosis, Parkinson's disease, Huntington's chorea, Alzheimer's disease, anxiety disorders, gastrointestinal disorders and/or cardiavascular disorders.

2. Discussion of Relevant Technology Pain management has been an important field of study for many years. It has been well known that cannabinoid receptor (e.g., CBi receptor, CB₂ receptor) ligands including agonists, antagonists and inverse agonists produce relief of pain in a variety of animal models by interacting with CBi and/or CB₂ receptors. Generally, CBi receptors are located predominately in the central nervous system, whereas CB receptors are located primarily in the periphery and are primarily restricted to the cells and tissues derived from the immune system. While CBi receptor agonists, such as Δ⁹-tetrahydrocannabinol (Δ⁹-THC) and anadamide, are useful in anti-nociception models in animals, they tend to exert undesired CNS side effects, e.g., psychoactive side effects, the abuse potential, drug dependence and tolerance, etc. These undesired side effects are known to be mediated by the CBi receptors located in CNS. There are lines of evidence, however, suggesting that CB l agonists acting at peripheral sites or with limited CNS exposure can manage pain in humans or animals with much improved overall in vivo profile. Therefore, there is a need for new CBi receptor ligands such as agonists that may be useful in managing pain or treating other related symptoms or diseases with reduced or minimal undesirable CNS side effects. DESCRIPTION OF THE EMBODIMENTS

The present invention provides CBi receptor ligands that may be useful in treating pain and/or other related symptoms or diseases. Unless specified otherwise within this specification, the nomenclature used in this specification generally follows the examples and rules stated in Nomenclature of Organic Chemistry, Sections A, B, C, D, E, F, and H, Pergamon Press, Oxford, 1979, which is incorporated by references herein for its exemplary chemical structure names and rules on naming chemical structures. The term "C_m-n" or "C_m._n group" used alone or as a prefix, refers to any group having m to n carbon atoms. The term "hydrocarbon" used alone or as a suffix or prefix, refers to any structure comprising only carbon and hydrogen atoms up to 14 carbon atoms. The term "hydrocarbon radical" or "hydrocarbyl" used alone or as a suffix or prefix, refers to any structure as a result of removing one or more hydrogens from a hydrocarbon. The term "alkyl" used alone or as a suffix or prefix, refers to a saturated monovalent straight or branched chain hydrocarbon radical comprising 1 to about 12 carbon atoms. Illustrative examples of alkyls include, but are not limited to, Cι_-6alkyl groups, such as methyl, ethyl, propyl, isopropyl, 2-methyl- 1 -propyl, 2-mefhy 1-2 -propyl, 2- methyl- 1 -butyl, 3-methyl- 1 -butyl, 2-mefhyl-3-butyl, 2,2-dimethyl- 1 -propyl, 2-methyl- 1 - pentyl, 3 -methyl- 1-pentyl, 4-methyl-l-pentyl, 2-methyl-2-pentyl, 3-methyl-2-pentyl, 4- methyl-2-pentyl, 2,2-dimethyl- 1 -butyl, 3,3-dimethyl-l-butyl, 2-ethyl-l -butyl, butyl, isobutyl, t-butyl, pentyl, isopentyl, neopentyl, and hexyl, and longer alkyl groups, such as heptyl, and octyl. An alkyl can be unsubstituted or substituted with one or two suitable substituents. The term "alkylene" used alone or as suffix or prefix, refers to divalent straight or branched chain hydrocarbon radicals comprising 1 to about 12 carbon atoms, which serves to links two structures together. The term "alkenyl" used alone or as suffix or prefix, refers to a monovalent straight or branched chain hydrocarbon radical having at least one carbon-carbon double bond and comprising at least 2 up to about 12 carbon atoms. The double bond of an alkenyl can be unconjugated or conjugated to another unsaturated group. Suitable alkenyl groups include, but are not limited to C₂-₆alkenyl groups, such as vinyl, allyl, butenyl, pentenyl, hexenyl, butadienyl, pentadienyl, hexadienyl, 2-ethylhexenyl, 2-propyl-2-butenyl, 4-(2-methyl-3- butene)-pentenyl. An alkenyl can be unsubstituted or substituted with one or two suitable substituents. The term "alkynyl" used alone or as suffix or prefix, refers to a monovalent straight or branched chain hydrocarbon radical having at least one carbon-carbon triple bond and comprising at least 2 up to about 12 carbon atoms. The triple bond of an alkynyl group can be unconjugated or conjugated to another unsaturated group. Suitable alkynyl groups include, but are not limited to, C_2-6alkynyl groups, such as ethynyl, propynyl, butynyl, pentynyl, hexynyl, methylpropynyl, 4-methyl-l -butynyl, 4-propyl-2-pentynyl, and 4-butyl- 2-hexynyl. An alkynyl can be unsubstituted or substituted with one or two suitable substituents. The term "cycloalkyl," used alone or as suffix or prefix, refers to a saturated monovalent ring-containing hydrocarbon radical comprising at least 3 up to about 12 carbon atoms. Examples of cycloalkyls include, but are not limited to, C_3-7cycloalkyl groups, such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and cycloheptyl, and saturated cyclic and bicyclic terpenes. A cycloalkyl can be unsubstituted or substituted by one or two suitable substituents. Preferably, the cycloalkyl is a monocyclic ring or bicyclic ring. The term "cycloalkenyl" used alone or as suffix or prefix, refers to a monovalent ring-containing hydrocarbon radical having at least one carbon-carbon double bond and comprising at least 3 up to about 12 carbon atoms. The term "cycloalkynyl" used alone or as suffix or prefix, refers to a monovalent ring-containing hydrocarbon radical having at least one carbon-carbon triple bond and comprising about 7 up to about 12 carbon atoms. The term "aryl" used alone or as suffix or prefix, refers to a monovalent hydrocarbon radical having one or more polyunsaturated carbon rings having aromatic character, (e.g., 4n + 2 delocalized electrons) and comprising 5 up to about 14 carbon atoms. The term "heterocycle" used alone or as a suffix or prefix, refers to a ring- containing structure or molecule having one or more multivalent heteroatoms, independently selected from N, O, P and S, as a part of the ring structure and including at least 3 and up to about 20 atoms in the ring(s). Heterocycle may be saturated or unsaturated, containing one or more double bonds, and heterocycle may contain more than one ring. When a heterocycle contains more than one ring, the rings may be fused or unfused. Fused rings generally refer to at least two rings share two atoms therebetween. Heterocycle may have aromatic character or may not have aromatic character. The term "heteroaromatic" used alone or as a suffix or prefix, refers to a ring- containing structure or molecule having one or more multivalent heteroatoms, independently selected from N, O, P and S, as a part of the ring structure and including at least 3 and up to about 20 atoms in the ring(s), wherein the ring-containing structure or molecule has an aromatic character (e.g., 4n + 2 delocalized electrons). The term "heterocyclic group," "heterocyclic moiety," "heterocyclic," or "heterocyclo" used alone or as a suffix or prefix, refers to a radical derived from a heterocycle by removing one or more hydrogens therefrom. The term "heterocyclyl" used alone or as a suffix or prefix, refers a monovalent radical derived from a heterocycle by removing one hydrogen therefrom. The term "heterocyclylene" used alone or as a suffix or prefix, refers to a divalent radical derived from a heterocycle by removing two hydrogens therefrom, which serves to links two structures together. The term "heteroaryl" used alone or as a suffix or prefix, refers to a heterocyclyl having aromatic character. The term "heterocylcoalkyl" used alone or as a suffix or prefix, refers to a monocyclic or polycyclic ring comprising carbon and hydrogen atoms and at least one heteroatom, preferably, 1 to 3 heteroatoms selected from nitrogen, oxygen, and sulfur, and having no unsaturation. Examples of heterocycloalkyl groups include pyrrolidinyl, pyrrolidino, piperidinyl, piperidino, piperazinyl, piperazino, morpholinyl, morpholino,' fhiomorpholinyl, thiomorpholino, and pyranyl. A heterocycloalkyl group can be unsubstituted or substituted with one or two suitable substituents. Preferably, the heterocycloalkyl group is a monocyclic or bicyclic ring, more preferably, a monocyclic ring, wherein the ring comprises from 3 to 6 carbon atoms and form 1 to 3 heteroatoms, referred to herein as C _-6heterocycloalkyl. The term "six-membered" used as prefix refers to a group having a ring that contains six ring atoms. The term "five-membered" used as prefix refers to a group having a ring that contains five ring atoms. A five-membered ring heteroaryl is a heteroaryl with a ring having five ring atoms wherein 1, 2 or 3 ring atoms are independently selected from N, O and S. Exemplary five-membered ring heteroaryls are thienyl, furyl, pyrrolyl, imidazolyl, thiazolyl, oxazolyl, pyrazolyl, isothiazolyl, isoxazolyl, 1,2,3-triazolyl, tetrazolyl, 1,2,3- thiadiazolyl, 1,2,3-oxadiazolyl, 1,2,4-triazolyl, 1,2,4-thiadiazolyl, 1,2,4-oxadiazolyl, 1,3,4- triazolyl, 1,3,4-thiadiazolyl, and 1,3,4- oxadiazolyl. A six-membered ring heteroaryl is a heteroaryl with a ring having six ring atoms wherein 1, 2 or 3 ring atoms are independently selected from N, O and S. Exemplary six-membered ring heteroaryls are pyridyl, pyrazinyl, pyrimidinyl, triazinyl and pyridazinyl. Heterocycle includes, for example, monocyclic heterocycles such as: aziridine, oxirane, thiirane, azetidine, oxetane, thietane, pyrrolidine, pyrroline, imidazolidine, pyrazolidine, pyrazoline, dioxolane, sulfolane 2,3-dihydrofuran, 2,5-dihydrofuran tetrahydrofuran, thiophane, piperidine, 1,2,3,6-tetrahydro-pyridine, piperazine, morpholine, thiomorpholine, pyran, thiopyran, 2,3-dihydropyran, tetrahydropyran, 1,4-dihydropyridine, 1,4-dioxane, 1,3-dioxane, dioxane, homopiperidine, 2,3,4,7-tetrahydro-lH-azepine homopiperazine, 1,3-dioxepane, 4,7-dihydro-l,3-dioxepin, and hexamethylene oxide. In addition, heterocycle includes aromatic heterocycles, for example, pyridine, pyrazine, pyrimidine, pyridazine, thiophene, furan, furazan, pyrrole, imidazole, thiazole, oxazole, pyrazole, isothiazole, isoxazole, 1,2,3-triazole, tetrazole, 1,2,3-thiadiazole, 1,2,3- oxadiazole, 1,2,4-triazole, 1,2,4-fhiadiazole, 1,2,4-oxadiazole, 1,3,4-triazole, 1,3,4- thiadiazole, and 1,3,4- oxadiazole. Additionally, heterocycle encompass polycyclic heterocycles, for example, indole, indoline, isoindoline, quinoline, tetrahydroquinoline, isoquinoline, tetrahydroisoquinoline, 1,4-benzodioxan, coumarin, dihydrocoumarin, benzofuran, 2,3-dihydrobenzofuran, isobenzofuran, chromene, chroman, isochroman, xanthene, phenoxathiin, thianthrene, indolizine, isoindole, indazole, purine, phthalazine, naphthyridine, quinoxaline, quinazoline, cinnoline, pteridine, phenanthridine, perimidine, phenanthroline, phenazine, phenothiazine, phenoxazine, 1,2-benzisoxazole, benzothiophene, benzoxazole, benzthiazole, benzimidazole, benztriazole, thioxanthine, carbazole, carboline, acridine, pyrolizidine, and quinolizidine. In addition to the polycyclic heterocycles described above, heterocycle includes polycyclic heterocycles wherein the ring fusion between two or more rings includes more than one bond common to both rings and more than two atoms common to both rings. Examples of such bridged heterocycles include quinuclidine, diazabicyclo[2.2.1]heptane and 7-oxabicyclo[2.2.1]heptane. Heterocyclyl includes, for example, monocyclic heterocyclyls, such as: aziridinyl, oxiranyl, thiiranyl, azetidinyl, oxetanyl, thietanyl, pyrrolidinyl, pyrrolinyl, imidazolidinyl, pyrazolidinyl, pyrazolinyl, dioxolanyl, sulfolanyl, 2,3-dihydrofuranyl, 2,5-dihydrofuranyl, tetrahydrofuranyl, thiophanyl, piperidinyl, 1,2,3,6-tetrahydro-pyridinyl, piperazinyl, morpholinyl, fhiomorpholinyl, pyranyl, thiopyranyl, 2,3-dihydropyranyl, tetrahydropyranyl, 1,4-dihydropyridinyl, 1 ,4-dioxanyl, 1,3-dioxanyl, dioxanyl, homopiperidinyl, 2,3,4,7-tetrahydro-lH-azepinyl, homopiperazinyl, 1,3-dioxepanyl, 4,7- dihydro-l,3-dioxepinyl, and hexamethylene oxidyl. In addition, heterocyclyl includes aromatic heterocyclyls or heteroaryl, for example, pyridinyl, pyrazinyl, pyrimidinyl, pyridazinyl, thienyl, furyl, furazanyl, pyrrolyl, imidazolyl, thiazolyl, oxazolyl, pyrazolyl, isothiazolyl, isoxazolyl, 1,2,3-triazolyl, tetrazolyl, 1,2,3-thiadiazolyl, 1,2,3-oxadiazolyl, 1,2,4-triazolyl, 1,2,4-thiadiazolyl, 1,2,4- oxadiazolyl, 1,3,4-triazolyl, 1,3,4-thiadiazolyl, and 1,3,4 oxadiazolyl. Additionally, heterocyclyl encompasses polycyclic heterocyclyls (including both aromatic or non-aromatic), for example, indolyl, indolinyl, isoindolinyl, quinolinyl, tetrahydroquinolinyl, isoquinolinyl, tetrahydroisoquinolinyl, 1,4-benzodioxanyl, coumarinyl, dihydrocoumarinyl, benzofuranyl, 2,3-dihydrobenzofuranyl, isobenzofuranyl, chromenyl, chromanyl, isochromanyl, xanthenyl, phenoxathiinyl, thianthrenyl, indolizinyl, isoindolyl, indazolyl, purinyl, phthalazinyl, naphthyridinyl, quinoxalinyl, quinazolinyl, cinnolinyl, pteridinyl, phenanthridinyl, perimidinyl, phenanthrolinyl, phenazinyl, phenothiazinyl, phenoxazinyl, 1,2-benzisoxazolyl, benzothiophenyl, benzoxazolyl, benzthiazolyl, benzimidazolyl, benztriazolyl, thioxanthinyl, carbazolyl, carbolinyl, acridinyl, pyrolizidinyl, and quinolizidinyl. In addition to the polycyclic heterocyclyls described above, heterocyclyl includes polycyclic heterocyclyls wherein the ring fusion between two or more rings includes more than one bond common to both rings and more than two atoms common to both rings. Examples of such bridged heterocycles include quinuclidinyl, diazabicyclo[2.2.1]heptyl; and 7-oxabicyclo[2.2.1]heptyl. The term "alkoxy" used alone or as a suffix or prefix, refers to radicals of the general formula -O-R, wherein R is selected from a hydrocarbon radical. Exemplary alkoxy includes methoxy, ethoxy, propoxy, isopropoxy, butoxy, t-butoxy, isobutoxy, cyclopropylmefhoxy, allyloxy, and propargyloxy. The term "amine" or "amino" used alone or as a suffix or prefix, refers to -NH₂. Halogen includes fluorine, chlorine, bromine and iodine. "Halogenated," used as a prefix of a group, means one or more hydrogens on the group is replaced with one or more halogens. "RT", "r.t." or "rt" means room temperature. "mCPBA" refers to wetα-Chloroperbenzoic acid. One aspect of the invention is a compound of formula I, a pharmaceutically acceptable salt thereof, diastereomers, enantiomers, or mixtures thereof:

I wherein: m is selected from 0, 1 and 2; n is selected from 0, 1, 2, 3, 4 and 5; R¹ is independently selected from halogen, cyano, amino, nitro, Cι.₆alkylamino, diCι.₆alkylamino, acetylamino, hydroxyl, Ci-βalkoxy, Cι.₆alkyl, halogenated Cι_-6alkoxy, C_1-6alkenyl, and halogenated C_1-6alkyl; R² is selected from C_δ-ioaryl and C₂-ιoheterocyclyl; wherein said C₆-ιoaryl and C₂. _loheterocyclyl used in defining R² is optionally substituted by one or more groups selected from halogen, halogenated Cι_-6alkyl, Cι_-6alkyl, cyano, nitro, Cι.₆alkoxy, halogenated . ₆alkoxy, hydroxy, hydroxy-C_1-6alkyl, amino, Cι-6alkoxy-Cι_-6alkyl, Ci-βalkylcarbonyl, Q. ₆alkoxycarbonyl, Cι.₆alkylamino, diCι_-6alkyl-amino, amino-Cι_-6alkyl, C _-6cycloalkyl, C₂. ₆heteroaryl, heteroaryl-Cι_-6alkyl, C_6-ι₀aryl, and C₆.ι₀aryl-C_1-6alkyl; and R³ is selected from hydrogen and Ci-βalkyl; R⁴ is selected from Cι_-6alkyl, C_3- ₇cycloalkyl, C _-7cycloalkenyl, Cβ-ioaryl, C_2-6heterocyclyl-amino, C2-6heterocyclyloxy- amino and C₂-₆heterocyclyl; wherein said Ci-βalkyl, C_3- cycloalkyl, C - cycloalkenyl, C₆. ioaryl, C_2-6heterocyclyl-amino, C2_-6heterocyclyloxy-amino and C_2-6heterocyclyl used in defining R⁴ is optionally substituted by one or more groups selected from halogen, halogenated Cι_-6alkyl,

hydroxy, hydroxy-Cι_-6alkyl, amino, Cι.₆alkoxy-Cι_-6alkyl, Cι.₆alkylcarbonyl, Cj. ₆alkoxycarbonyl, Cι_-6alkylamino, diC]_-6alkyl-amino, amino-d-όalkyl, C_3-6cycloalkyl, C₂.

₆heteroaryl, heteroaryl-Cι.₆alkyl, C_6-ιoaryl, and Ce-io ryl-Ci-βalkyl; or

is C_2-ιoheterocyclyl, which is optionally substituted by one or more groups selected from halogen, halogen substituted Ci-όalkyl, Cι_-6alkyl, cyano, nitro, Ci-βalkoxy, halogenated Ci- ₆alkoxy, hydroxy, hydroxy-Cι.₆alkyl, amino, Cι.₆alkoxy-Cι.₆alkyl, Cι.₆alkylcarbonyl, Ci. ₆alkoxycarbonyl, Cι.₆alkylamino, diC^ealkyl-amino, amino-Ci-ealkyl, C_3-6cycloalkyl, C_2- ₆heteroaryl, heteroaryl-Cι.₆alkyl, C_6-ιoaryl, and C_ό-io ryl- .ealkyl. In another embodiment, the compounds of the present invention are those of formula I, wherein m is selected from 0, 1 and 2; n is selected from 0, 1, 2, 3 and 4; R¹ is independently selected from halogen, cyano, amino, nitro, acetylamino, hydroxyl, Cι- alkoxy, Cι_-3alkyl, halogenated Cι_-3alkoxy, and halogenated Cι_-3alkyl; R² is selected from Cβ-ioaryl and C₂-ιoheterocyclyl, wherein said C_6-ιoaryl and C_2- _loheterocyclyl used in defining R² is optionally substituted by one or more groups selected from halogen, halogenated Cι_-3alkyl, C_1-3alkyl, nitro, Cι_-3alkoxy, halogenated Cι_-3alkoxy, hydroxy, hydroxy-Cι_-3alkyl, amino, Cι_-3alkoxy-Cι_-3alkyl, C2.₅heterocyclyl-Cι- alkyl, C_\. ₆alkoxycarbonyl, Cι_-3alkylamino, diCι- alkyl-amino, arnino-C^alkyl; and R³ is selected from hydrogen and C_1-6 alkyl; R⁴ is selected from d.₆alkyl, C . ₇cycloalkyl, C₂-₆heterocyclyl-amino, C_2-6heterocyclyloxy-amino, and C_2-6 heterocyclyl; wherein said Cι_-6alkyl, C .₇cycloalkyl, C _-6heterocyclyl-amino, C_2-6heterocyclyloxy-amino, and C_2-6 heterocyclyl used in defining R⁴ is optionally substituted by one or more groups selected from halogen, halogenated C_]- alkyl, Cι- alkyl, nitro, Cι_-3alkoxy, halogenated C_\. ₃alkoxy, hydroxy, hydroxy-Cι_-3 alkyl, amino, Cι_-3alkoxy-Cι_-3alkyl, Cι_-6alkoxycarbonyl, C_\. _κ(CH₂)-R⁴ N 3 ₃alkylamino, diCι.₃alkyl-amino, and amino-Cι_-3alkyl; or R is selected from azepanyl, pyrrolyl, pyrrolinyl, pyrrolidinyl, imidazolyl, imidazolidinyl, pyrazolyl, pyrazolinyl, pyrazolidinyl, isoxazolidinyl, triazolyl, mo holinyl, piperidinyl, fhiomorpholinyl, pyridazinyl, piperazinyl, triazinyl or l,4-dioxa-8-azaspiro[4.5]decan-8-yl; wherein said azepanyl, pyrrolyl, pyrrolinyl, pyrrolidinyl, imidazolyl, imidazolidinyl, pyrazolyl, pyrazolinyl, pyrazolidinyl, isoxazolidinyl, trazolyl, morpholinyl, piperidinyl, fhiomorpholinyl, piperazinyl, triazinyl and l,4-dioxa-8-azaspiro[4.5]decan-8-yl are optionally substituted by one or more groups selected from halogen, halogenated Cι.₃alkyl, Cι- alkyl, nitro, Cι_-3alkoxy, halogenated C_1- alkoxy, hydroxy, hydroxy-C_1-3alkyl, amino, Cι.₃alkoxy-C_1- alkyl, Cι.₆alkoxycarbonyl, Cι_-3alkylamino, diC_1-3alkyl-amino, and amino- C_1-3alkyl. In a further embodiment, the compounds of the present invention are those of formula I, wherein m is selected from 0 and 1 ; n is selected from 0, 1, 2, 3 and 4; R¹ is independently selected from halogen, amino, nitro, acetylamino, hydroxyl, Q. alkoxy, Cι.₃alkyl, halogenated Cι_-3alkoxy, and halogenated Cι_-3alkyl; R² is selected from phenyl, naphthyl, pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, thienyl, furyl, pyrrolyl, imidazolyl, thiazolyl, oxazolyl, pyrazolyl, isothiazolyl, isoxazolyl, 1,2,3-triazolyl, tetrazolyl, 1,2,3-thiadiazolyl, 1,2,3-oxadiazolyl, 1,2,4-triazolyl, 1,2,4- thiadiazolyl, 1,2,4-oxadiazolyl, 1,3,4-triazolyl, 1,3,4-fhiadiazolyl, and 1,3,4 oxadiazolyl, indolyl, indolinyl, quinolinyl, tetrahydroquinolinyl, isoquinolinyl, tetrahydroisoquinolinyl, 1,4-benzodioxanyl, coumarin, dihydrocoumarinyl, 2,3-dihydrobenzofuranyl, 1,2- benzisoxazolyl, 1,3-benzodioxolyl, 2,3-dihydro-l,4-benzodioxinyl, 3,4-dihydro-2H-l,5- benzodioxepinyl, 4H-l,3-benzodioxinyl, benzofuranyl, benzothiophenyl, benzoxazolyl, benzthiazolyl, benzimidazolyl, benztriazolyl, thioxanthinyl, carbazolyl, carbolinyl, acridinyl, pyrolizidinyl, and quinolizidinyl that are optionally substituted by one or more groups selected from halogen, hydroxy, methyl, methoxy, amino, trifluoromethyl, trifluoromethoxy, methoxymethyl, lH-l,2,3-triazolylmefhyl and lH-pyrazolylmethyl; R³ is selected from hydrogen and Cι_-6 alkyl; and R⁴ is selected from

pyrrolidin-l -amino, piperidin-1 -amino, O-cyclohexyl ydroxyamino, O- cyclopentylhydroxyamino, O-cyclobutylhydroxyamino, O-cyclopropylhydroxyamino, and Cι.₃alkyl that are optionally substituted by one or more groups selected from halogen, amino, aminomethyl, 2-aminoethyl, hydroxy, hydroxylmethyl, methyl and ethyl, Particularly, R² is selected from

that are optionally substituted with one or more groups selected from halogen, methyl, methoxy, hydroxyl, methoxymethyl, lH-l,2,3-triazolylmethyl and 1H-1,2- diazolylmethyl. In an even further embodiment, the compounds of the present invention are those of formula I and pharmaceutically acceptable salts thereof, wherein m is 1 ; n is selected from 0, 1, 2, and 3; R¹ is independently selected from halogen, amino, nitro, acetylamino, hydroxyl, Q. alkoxy, C_1-3alkyl, halogenated Cι_-3alkoxy, and halogenated Cι_-3alkyl; R² is selected from phenyl, naphthyl, pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, thienyl, furyl, pyrrolyl, imidazolyl, thiazolyl, oxazolyl, pyrazolyl, isothiazolyl, isoxazolyl, 1,2,3-triazolyl, tetrazolyl, 1,2,3-thiadiazolyl, 1,2,3-oxadiazolyl, 1,2,4-triazolyl, 1,2,4- thiadiazolyl, 1,2,4-oxadiazolyl, 1,3,4-triazolyl, 1,3,4-fhiadiazolyl, and 1,3,4 oxadiazolyl, indolyl, indolinyl, quinolinyl, tetrahydroquinolinyl, isoquinolinyl, tetrahydroisoquinolinyl, 1 ,4-benzodioxanyl, coumarin, dihydrocoumarinyl, 2,3-dihydrobenzofuranyl, 1,2- benzisoxazolyl, 1,3-benzodioxolyl, 2,3-dihydro-l,4-benzodioxinyl, 3,4-dihydro-2H-l,5- benzodioxepinyl, 4H-l,3-benzodioxinyl, benzofuranyl, benzothiophenyl, benzoxazolyl, benzthiazolyl, benzimidazolyl, benztriazolyl, thioxanthinyl, carbazolyl, carbolinyl, acridinyl, pyrolizidinyl, and quinolizidinyl that are optionally substituted by one or more groups selected from halogen, hydroxy, methyl, methoxy, amino, trifluoromethyl, trifluoromethoxy, methoxymethyl, lH-l,2,3-triazolylmethyl, lH-pyrazolylmethyl; and

s selecte rom azet ny , azepany , soxazo nyl, morpholinyl, piperazinyl, piperidinyl, pyrrolidinyl, and l,4-dioxa-8-azaspiro[4.5]decan-8- yl that were optionally substituted with one or more groups selected from halogen, cyano, nitro, methyl, ethyl, hydroxy, hydroxy-methyl, hydroxy-ethyl, amino-methyl, amino-ethyl, methoxy-methyl, methoxy-phenyl, ethoxycarbonyl, tert-butoxycarbonyl, diphenyl-methyl, morpholinyl-eth-2-yl, piperidinyl-mefhyl and pyridinyl.

Particularly,

More particularly, R is selected from

that are optionally substituted with one or more groups selected from halogen, methyl, methoxy, hydroxyl, methoxymefhyl, lH-l,2,3-triazolylmethyl and 1H- pyrazolylmethyl. In a more particularly embodiment, R² is selected from

optionally substituted with one or more groups selected from halogen, methyl, methoxy, hydroxyl, methoxymethyl, lH-l,2,3-triazolylmethyl and lH-pyrazolylmethyl. It will be understood that when compounds of the present invention contain one or more chiral centers, the compounds of the invention may exist in, and be isolated as, enantiomeric or diastereomeric forms, or as a racemic mixture. The present invention includes any possible enantiomers, diastereomers, racemates or mixtures thereof, of a compound of Formula I. The optically active forms of the compound of the invention may be prepared, for example, by chiral chromatographic separation of a racemate, by synthesis from optically active starting materials or by asymmetric synthesis based on the procedures described thereafter. It will also be appreciated that certain compounds of the present invention may exist as geometrical isomers, for example E and Z isomers of alkenes. The present invention includes any geometrical isomer of a compound of Formula I. It will further be understood that the present invention encompasses tautomers of the compounds of the formula I. It will also be understood that certain compounds of the present invention may exist in solvated, for example hydrated, as well as unsolvated forms. It will further be understood that the present invention encompasses all such solvated forms of the compounds of the formula I. Within the scope of the invention are also salts of the compounds of the formula I. Generally, pharmaceutically acceptable salts of compounds of the present invention may be obtained using standard procedures well known in the art, for example by reacting a sufficiently basic compound, for example an alkyl amine with a suitable acid, for example, HCl or acetic acid, to afford a physiologically acceptable anion. It may also be possible to make a corresponding alkali metal (such as sodium, potassium, or lithium) or an alkaline earth metal (such as a calcium) salt by treating a compound of the present invention having a suitably acidic proton, such as a carboxylic acid or a phenol with one equivalent of an alkali metal or alkaline earth metal hydroxide or alkoxide (such as the ethoxide or methoxide), or a suitably basic organic amine (such as choline or meglumine) in an aqueous medium, followed by conventional purification techniques. In one embodiment, the compound of formula I above may be converted to a pharmaceutically acceptable salt or solvate thereof, particularly, an acid addition salt such as a hydrochloride, hydrobromide, phosphate, acetate, fumarate, maleate, tartrate, citrate, methanesulphonate orp-toluenesulphonate.

We have now found that the compounds of the invention have activity as pharmaceuticals, in particular as modulators or ligands such as agonists, partial agonists, inverse agonist or antagonists of CBi receptors. More particularly, the compounds of the invention exhibit activity as agonist of the CBi receptors and are useful in therapy, especially for relief of various pain conditions such as chronic pain, neuropathic pain, acute pain, cancer pain, pain caused by rheumatoid arthritis, migraine, visceral pain etc. This list should however not be interpreted as exhaustive. Additionally, compounds of the present invention are useful in other disease states in which dysfunction of CBi receptors is present or implicated. Furthermore, the compounds of the invention may be used to treat cancer, multiple sclerosis, Parkinson's disease, Huntington's chorea, Alzheimer's disease, anxiety disorders, gastrointestinal disorders and cardiavascular disorders. Compounds of the invention are useful as immunomodulators, especially for autoimmune diseases, such as arthritis, for skin grafts, organ transplants and similar surgical needs, for collagen diseases, various allergies, for use as anti-tumour agents and anti viral agents. Compounds of the invention are useful in disease states where degeneration or dysfunction of cannabinoid receptors is present or implicated in that paradigm. This may involve the use of isotopically labelled versions of the compounds of the invention in diagnostic techniques and imaging applications such as positron emission tomography (PET). Compounds of the invention are useful for the treatment of diarrhoea, depression, anxiety and stress-related disorders such as post-traumatic stress disorders, panic disorder, generalized anxiety disorder, social phobia, and obsessive compulsive disorder, urinary incontinence, premature ejaculation, various mental illnesses, cough, lung oedema, various gastro-intestinal disorders, e.g. constipation, functional gastrointestinal disorders such as Irritable Bowel Syndrome and Functional Dyspepsia, Parkinson's disease and other motor disorders, traumatic brain injury, stroke, cardioprotection following miocardial infarction, spinal injury and drug addiction, including the treatment of alcohol, nicotine, opioid and other drug abuse and for disorders of the sympathetic nervous system for example hypertension. Compounds of the invention are useful as an analgesic agent for use during general anaesthesia and monitored anaesthesia care. Combinations of agents with different properties are often used to achieve a balance of effects needed to maintain the anaesthetic state (e.g. amnesia, analgesia, muscle relaxation and sedation). Included in this combination are inhaled anaesthetics, hypnotics, anxiolytics, neuromuscular blockers and opioids. In another aspect of the invention is the use of a compound according to formula I for inhibition of transient lower esophageal sphincter relaxations (TLESRs) and thus for treatment or prevention of gastroesophageal reflux disorder (GERD). The major mechanism behind reflux has been considered to depend on a hypotonic lower esophageal sphincter. However, e.g. Holloway & Dent (1990) Gastroenterol. Clin. N. Amer. 19, pp. 517-535, has shown that most reflux episodes occur during transient lower esophageal sphincter relaxations (TLESRs), i.e. relaxations not triggered by swallows. In further embodiments, the compounds according to the present invention are useful for the prevention of reflux, treatment or prevention of regurgitation, treatment or prevention of asthma, treatment or prevention of laryngitis, treatment or prevention of lung disease and for the management of failure to thrive. A further aspect of the invention is the use of a compound according to formula I for the manufacture of a medicament for the inhibition of transient lower esophageal sphincter relaxations, for the treatment or prevention of GERD, for the prevention of reflux, for the treatment or prevention of regurgitation, treatment or prevention of asthma, treatment or prevention of laryngitis, treatment or prevention of lung disease and for the management of failure to thrive. An even further aspect of the invention is the use of a compound according to formula I for the manufacture of a medicament for the treatment or prevention of functional gastrointestinal disorders, such as functional dyspepsia (FD). Yet another aspect of the invention is the use of a compound according to formula I for the manufacture of a medicament for the treatment or prevention of irritable bowel syndrome (IBS), such as constipation predominant IBS, diarrhea predominant IBS or alternating bowel movement predominant IBS. Exemplary irritable bowel syndrome (IBS) and functional gastrointestinal disorders, such as functional dyspepsia, are illustrated in Thompson WG, Longstreth GF, Drossman DA, Heaton KW, Irvine EJ, Mueller-Lissner SA. C. Functional Bowel Disorders and Functional Abdominal Pain. In: Drossman DA, Talley NJ, Thompson WG, Whitehead WE, Coraziarri E, eds. Rome II: Functional Gastrointestinal Disorders: Diagnosis, Pafhophysiology and Treatment. 2 ed. McLean, NA: Degnon Associates, Inc.; 2000:351-432 and Drossman DA, Corazziari E, Talley ΝJ, Thompson WG and Whitehead WE. Rome II: A multinational consensus document on Functional Gastrointestinal Disorders. Gut 45(Suppl.2), 111-1181.9-1-1999. Also within the scope of the invention is the use of any of the compounds according to the formula I above, for the manufacture of a medicament for the treatment of any of the conditions discussed above. A further aspect of the invention is a method for the treatment of a subject suffering from any of the conditions discussed above, whereby an effective amount of a compound according to the formula I above, is administered to a patient in need of such treatment. Thus, the invention provides a compound of formula I, or pharmaceutically acceptable salt or solvate thereof, as hereinbefore defined for use in therapy. In a further aspect, the present invention provides the use of a compound of formula I, or a pharmaceutically acceptable salt or solvate thereof, as hereinbefore defined in the manufacture of a medicament for use in therapy. In the context of the present specification, the term "therapy" also includes "prophylaxis" unless there are specific indications to the contrary. The term "therapeutic" and "therapeutically" should be contrued accordingly. The term "therapy" within the context of the present invention further encompasses to administer an effective amount of a compound of the present invention, to mitigate either a pre-existing disease state, acute or chronic, or a recurring condition. This definition also encompasses prophylactic therapies for prevention of recurring conditions and continued therapy for chronic disorders. The compounds of the present invention are useful in therapy, especially for the therapy of various pain conditions including, but not limited to: acute pain, chronic pain, neuropathic pain, back pain, cancer pain, and visceral pain. In use for therapy in a warm-blooded animal such as a human, the compound of the invention may be administered in the form of a conventional pharmaceutical composition by any route including orally, intramuscularly, subcutaneously, topically, intranasally, intraperitoneally, intra horacially, intravenously, epidurally, intrathecally, intracerebroventricularly and by injection into the joints. In one embodiment of the invention, the route of administration may be oral, intravenous or intramuscular. The dosage will depend on the route of administration, the severity of the disease, age and weight of the patient and other factors normally considered by the attending physician, when determining the individual regimen and dosage level at the most appropriate for a particular patient. For preparing pharmaceutical compositions from the compounds of this invention, inert, pharmaceutically acceptable carriers can be either solid and liquid. Solid form preparations include powders, tablets, dispersible granules, capsules, cachets, and suppositories. A solid carrier can be one or more substances, which may also act as diluents, flavoring agents, solubilizers, lubricants, suspending agents, binders, or table disintegrating agents; it can also be an encapsulating material, In powders, the carrier is a finely divided solid, which is in a mixture with the finely divided compound of the invention, or the active component. In tablets, the active component is mixed with the carrier having the necessary binding properties in suitable proportions and compacted in the shape and size desired. For preparing suppository compositions, a low-melting wax such as a mixture of fatty acid glycerides and cocoa butter is first melted and the active ingredient is dispersed therein by, for example, stirring. The molten homogeneous mixture in then poured into convenient sized moulds and allowed to cool and solidify. Suitable carriers are magnesium carbonate, magnesium stearate, talc, lactose, sugar, pectin, dextrin, starch, tragacanfh, methyl cellulose, sodium carboxymethyl cellulose, a low-melting wax, cocoa butter, and the like. The term composition is also intended to include the formulation of the active component with encapsulating material as a carrier providing a capsule in which the active component (with or without other carriers) is surrounded by a carrier which is thus in association with it. Similarly, cachets are included. Tablets, powders, cachets, and capsules can be used as solid dosage forms suitable for oral administration. Liquid form compositions include solutions, suspensions, and emulsions. For example, sterile water or water propylene glycol solutions of the active compounds may be liquid preparations suitable for parenteral administration. Liquid compositions can also be formulated in solution in aqueous polyethylene glycol solution. Aqueous solutions for oral administration can be prepared by dissolving the active component in water and adding suitable colorants, flavoring agents, stabilizers, and thickening agents as desired. Aqueous suspensions for oral use can be made by dispersing the finely divided active component in water together with a viscous material such as natural synthetic gums, resins, methyl cellulose, sodium carboxymethyl cellulose, and other suspending agents known to the pharmaceutical formulation art. Depending on the mode of administration, the pharmaceutical composition will preferably include from 0.05% to 99%w (per cent by weight), more preferably from 0.10 to 50%w, of the compound of the invention, all percentages by weight being based on total composition. A therapeutically effective amount for the practice of the present invention may be determined, by the use of known criteria including the age, weight and response of the individual patient, and interpreted within the context of the disease which is being treated or which is being prevented, by one of ordinary skills in the art. Within the scope of the invention is the use of any compound of formula I as defined above for the manufacture of a medicament. Also within the scope of the invention is the use of any compound of formula I for the manufacture of a medicament for the therapy of pain. Additionally provided is the use of any compound according to Formula I for the manufacture of a medicament for the therapy of various pain conditions including, but not limited to: acute pain, chronic pain, neuropathic pain, back pain, cancer pain, and visceral pain. A further aspect of the invention is a method for therapy of a subject suffering from any of the conditions discussed above, whereby an effective amount of a compound according to the formula I above, is administered to a patient in need of such therapy. Additionally, there is provided a pharmaceutical composition comprising a compound of Formula I, or a pharmaceutically acceptable salt thereof, in association with a pharmaceutically acceptable carrier. Particularly, there is provided a pharmaceutical composition comprising a compound of Formula I, or a pharmaceutically acceptable salt thereof, in association with a pharmaceutically acceptable carrier for therapy, more particularly for therapy of pain. Further, there is provided a pharmaceutical composition comprising a compound of

Formula I, or a pharmaceutically acceptable salt thereof, in association with a pharmaceutically acceptable carrier use in any of the conditions discussed above. Another aspect of the invention is a method of preparing the compounds of the present invention. In one embodiment, the method of the invention is a method for preparing a compound of formula I,

I comprising the step of reacting a compound of formula II,

π with mCPBA, in the presence of a solvent such as CH2CI2, wherein: m is selected from 0, 1 and 2; n is selected from 0, 1, 2, 3, 4 and 5; R¹ is independently selected from halogen, cyano, amino, nitro, Ci-ealkylamino, diCi-βalkylamino, acetylamino, hydroxyl, Cι.₆alkoxy, C_halky 1, halogenated Cι_-6alkoxy, d^alkenyl, and halogenated Ci^alkyl; R² is selected from C₆-ioaryl and C_2-1oheterocyclyl; wherein said C_δ-ioaryl and C₂- _loheterocyclyl used in defining R is optionally substituted by one or more groups selected from halogen, halogenated Cι-₆alkyl, d-βalkyl, cyano, nitro, d^alkoxy, halogenated Ci. ₆alkoxy, hydroxy, hydroxy-Cι.₆alkyl, amino, Cι.₆alkoxy-d.₆alkyl, Cι.₆alkylcarbonyl, Ci. _όalkoxycarbonyl, Cι.₆alkylamino, diCι.₆alkyl-amino, amino-C βalkyl, C_2-5heterocyclyl-C_1- ₃alkyl, C_3-6cycloalkyl, C_2-6heteroaryl, heteroaryl-d.₆alkyl, C_6-ι₀aryl, and C₆-ioaryl-Ci. ₆alkyl; and R³ is selected from hydrogen and C_1-6alkyl; R⁴ is selected from Cι.₆alkyl, C_3- ₇cycloalkyl, C_4-7cycloalkenyl, C_6-ιoaryl, d-eheterocyclyl-amino, d-όheterocyclyloxy- amino, and C_2-6heterocyclyl; wherein said Cι_-6alkyl, C_3-7cycloalkyl, C_4- cycloalkenyl, C_6- ι₀aryl, C_2-6heterocyclyl-amino, C₂-₆heterocyclyloxy-amino, and C_2-6heterocyclyl used in defining R⁴ is optionally substituted by one or more groups selected from halogen, halogenated Cι-₆alkyl, Cι_-6alkyl, cyano, nitro, Ci-βalkoxy, halogenated Ci._όalkoxy, hydroxy, hydroxy-Cι_-6alkyl, amino, Cι.₆alkoxy-Cι_-6alkyl, Cι-6alkylcarbonyl, Ci- ₆aikoxycarbonyl, Cι_-6alkylamino, diCι.₆alkyl-amino, amino-Cι-₆alkyl, C_3-6cycloalkyl, C₂-

₆heteroaryl, heteroaryl-Cι_-6alkyl, C_6-ι₀aryl, and C₆-ιoaryl-C_1-6alkyl; or

is selected from a C_2-10heterocyclyl, which is optionally substituted by one or more groups selected from halogen, halogen substituted Cι_-6alkyl, C_1-6alkyl, cyano, nitro, C_1-6alkoxy, halogenated d-βalkoxy, hydroxy, hydroxy-C_1-6alkyl, amino, Ci-όalkoxy-Ci-δalkyl, Ci.

₆alkylcarbonyl, C_1-6alkoxycarbonyl, Cι_-6alkylamino, diC όalkyl-amino, amino-C_1-6alkyl,

C_3-6cycloalkyl, C_2-6heteroaryl, heteroaryl-Cι.₆alkyl, C_6-ιoaryl, and C₆.ιoaryl-Cι.₆alkyl. Compounds of the present invention may be prepared according to, but not limited to, the synthetic routes as depicted in Schemes 1 and 2. Scheme 1. A synthetic route used for the synthesis of compounds including Examples 1 -7.

base, e.g. DIPEΞA solvent, e.g. DMF

coupling reagent, e.g. HATU

Scheme 2. A synthetic route used for the synthesis of compounds including Examples 8-10.

BIOLOGICAL EVALUATION

hCB^ and hCB? receptor binding Human CBi receptor from Receptor Biology (hCBi) or human CB₂ receptor from BioSignal (hCB2) membranes are thawed at 37 °C, passed 3 times through a 25-gauge blunt-end needle, diluted in the cannabinoid binding buffer (50 mM Tris, 2.5 mM EDTA, 5 mM MgCl₂, and 0.5 mg/mL BSA fatty acid free, pH 7.4) and aliquots containing the appropriate amount of protein are distributed in 96-well plates. The IC₅0 of the compounds of the invention at hCBi and hCB₂ are evaluated from 10-point dose-response curves done with ³H-CP55,940 at 20000 to 25000 dpm per well (0.17-0.21 nM) in a final volume of 300 μl. The total and non-specific binding are determined in the absence and presence of 0.2 μM of HU210 respectively. The plates are vortexed and incubated for 60 minutes at room temperature, filtered through Unifilters GF/B (presoaked in 0.1% polyethyleneimine) with the Tomtec or Packard harvester using 3 mL of wash buffer (50 mM Tris, 5 mM MgCl₂, 0.5 mg BSA pH 7.0). The filters are dried for 1 hour at 55 °C. The radioactivity (cpm) is counted in a TopCount (Packard) after adding 65 μl/well of MS-20 scintillation liquid.

hCBi and hCB? GTPΎS binding Human CBi receptor from Receptor Biology (hCBi) or human CB₂ receptor membranes (BioSignal) are thawed at 37 °C, passed 3 times through a 25-gauge blunt-end needle and diluted in the GTPγS binding buffer (50 mM Hepes, 20 mM NaOH, 100 mM NaCl, 1 mM EDTA, 5 mM MgCl₂, pH 7.4, 0.1% BSA). The EC₅₀ and E_raax of the compounds of the invention are evaluated from 10-point dose-response curves done in 300μl with the appropriate amount of membrane protein and 100000-130000 dpm of GTPg³⁵S per well (0.11 -0.14 nM). The basal and maximal stimulated binding is determined in absence and presence of 1 μM (hCB₂) or 10 μM (hCBi) Win 55,212-2 respectively. The membranes are pre-incubated for 5 minutes with 56.25 μM (hCB2) or 112.5 μM (hCBi) GDP prior to distribution in plates (15 μM (hCB₂) or 30 μM (hCB GDP final). The plates are vortexed and incubated for 60 minutes at room temperature, filtered on Unifϊlters GF/B (presoaked in water) with the Tomtec or Packard harvester using 3 ml of wash buffer (50 mM Tris, 5 mM MgCl₂, 50 mM NaCl, pH 7.0). The filters are dried for 1 hour at 55 °C. The radioactivity (cpm) is counted in a TopCount (Packard) after adding 65 μl/well of MS-20 scintillation liquid. Antagonist reversal studies are done in the same way except that (a) an agonist dose-response curve is done in the presence of a constant concentration of antagonist, or (b) an antagonist dose-response curve is done in the presence of a constant concentration of agonist. Based on the above assays, the dissociation constant (Ki) for a particular compound of the invention towards a particular receptor is determined using the following equation: Ki = IC₅₀/(l+[rad]/Kd), Wherein IC₅₀ is the concentration of the compound of the invention at which 50% displacement has been observed; [rad] is a standard or reference radioactive ligand concentration at that moment; and Kd is the dissociation constant of the radioactive ligand towards the particular receptor. Using the above-mentioned assays, the Ki towards human CBi receptors for most compounds of the invention is measured to be in the range of 14800 nM. The Ki towards human CB2 receptors for most compounds of the invention is measured to be in the range of about 37-1843 nM. The EC₅₀ towards human CBi receptors for most compounds of the invention is measured to be in the range of about 149-2800 nM. The E_max towards human CBi receptors for most compounds of the invention is measured to be in the range of about 105-128%. The following table shows certain biological activities for some of the exemplified compounds.

EXAMPLES

The invention will further be described in more detail by the following Examples which describe methods whereby compounds of the present invention may be prepared, purified, analyzed and biologically tested, and which are not to be construed as limiting the invention.

Example 1 N-(Cyclobuty lmethyl)-3 - [( 1 -naphthalenylcarbonyl)amino] - 1 -oxide -2-pyridinecarboxamide

Step A. N-(Cyclobutylmethyl)-3-[(l-naphthalenylcarbonyl)amino]-l-oxide-2- pyridinecarboxamide

N-(Cyclobutylmefhyl)-3-[(l-naphthalenylcarbonyl)amino]-2-pyridinecarboxamide (156 mg, 0.422 mmol, see Steps B & C for its preparation) in CH₂C1₂ (10 mL) was treated with 3-chloroperoxybenzoic acid (500 mg, 1.65 mmol) for 48 h at room temperature. The mixture was diluted with CH₂C1₂ (100 mL), washed with 1 NNaOH (2x10 mL) and dried over Na2SO₄. After filtration and concentration, the crude products were purified by MPLC using Hex EtOAc (1 : 1) on Siθ₂ to provide the title compound as a white solid (114 mg, 83%). 1H NMR (400 MHz, CDC1₃) δ 1.75 (m, 2 H), 1.89 (m, 2 H), 2.10 (m, 2 H), 2.61 (m, 1 H), 3.45 (dd, J=7.23, 5.47 Hz, 2 H), 7.41 (dd, J=8.79, 6.44 Hz, 1 H) ,7.57 (m, 3 H) , 7.90 (m, 2 H) , 8.00 (d, J=8.40 Hz, 1 H), 8.09 (dd, J=6.44, 1.17 Hz, 1 H) ,8.52 (dd, J=8.20, 0.98 Hz, 1 H) , 9.23 (dd, J=8.89, 1.27 Hz, 1 H), 12.15 (s, 1 H), 13.74 (s, 1 H). MS (ESI) (M+H)⁺ 376.3. Anal. Calcd for C₂₂H₂ιN₃O₃+0.1 H₂O: C, 70.05; H, 5.66; N, 11.14. Found: C, 70.00; H, 5.75; N, 11.17.

Step B. 2-(l-Naphthalenyl)-H-pyrido[3,2-cT|[l,3]oxazin-4-one

1-Naphthalenecarbonyl chloride (400 mg, 2.1 mmol) in CH₂Cl2 (2 mL) was added into a solution of 3-amino-2-pyridinecarboxylic acid (277 mg , 2.0 mmol) and diisopropylefhylamine (284 mg, 2.2 mmol) in DMF (10 mL) at 0 °C. The reaction mixture was allowed to stir overnight at room temperature, and was then treated with diisopropylefhylamine (284 mg, 2.2 mmol) and HATU (837 g, 2.2 mmol). After stirring for 1 h at room temperature, the reaction mixture was heated at 50 °C to provide the title compound which was used in Step A. MS (ESI) (M+H)⁺ 274.79.

Step C. N-(Cyclobutylmethyl)-3-[(l-naphthalenylcarbonyl)amino]-2-pyridinecarboxamide

A solution of 2-(l-naph alenyl)-H-pyrido[3,2-d][l,3]oxazin-4-one (100 mg, 0.365 mmol, see Step B for its preparation) in DMF (2 mL) was treated with cyclobutane methylamine (0.1 mL, 5.3 Min MeOΗ, 0.53 mmol) at 0 °C. The mixture was stirred for 18 h at room temperature. After evaporation of the solvent, the residue was purified by MPLC using Ηex/EtOAc (9: 1) on SiO₂ to provide the title compound (156 mg, 83%). 1H ΝMR (400 MHz, CDC1₃) δ 1.69-1.78 (m, 2 H), 1.81-1.91 ( , 2 H), 1.99-2.07 (m, 2 H), 2.51-2.62 (m, 1 H), 3.34 (d, J=7.03 Hz, 2 H), 7.52-7.59 (m, 4 H), 7.87-7.89 (m, 1 H), 7.92-7.96 (m, 1 H), 8.03-8.05 (m, 1 H), 8.30-8.35 (m, 1 H), 8.42-8.45 (m, 1 H), 9.27 (dd, J=8.59, 1.17 Hz, 1 H). MS (ESI) (M+H)⁺ 360.0. Anal. (C, H, Ν) calcd for C₂2H₂ιΝ₃O₂+0.3 CH₃OH: C 72.58, H 6.06, N 11.39; found C 72.58, H 5.86, N 11.30.

Example 2 N-(Cyclobutylmefhyl)-3 -[[(4-methyl- 1 -naphthalenyl)carbonyl] amino]- 1 -oxide-2- pyridinecarboxamide

Step A. N-(Cyclobutylmefhyl)-3-[[(4-methyl-l-naphthalenyl)carbonyl]amino]-l-oxide-2- pyridinecarboxamide

Following the procedure for Step A in Example 1, N-(cyclobutylmethyl)-3-[[(4-methyl-l- naphthalenyl)carbonyl]amino]-2-pyridinecarboxamide (105 mg, 0.279 mmol, see Steps B & C for its preparation) in CH₂CI₂ (10 mL) was treated with 3-chloroperoxybenzoic acid (422 mg, 1.4 mmol) . The crude products were purified by reverse phase HPLC using 60- 85% MeCN/H₂O to provide the title compound as a white solid (45 mg, 41 %). H NMR (400 MHz, CD₃OD) δ 1.77 (m, 2 H), 1.88 (m, 2 H), 2.05 (m, 2 H), 2.59 (m, 1 H), 2.75 (s, 3 H), 3.41 (d, J=7.03 Hz, 2 H), 7.44 (d, J=7.62 Hz, 1 H), 7.59 (m, 3 H), 7.77 (d, J=7.23 Hz, 1 H), 8.13 (m, 1 H), 8.19 (dd, J=6.44, 0.78 Hz, 1 H), 8.45 (m, 1 H), 9.04 (dd, J=8.79, 0.98 Hz, 1 H). MS (ESI) (M+H)⁺ 390.0.

Step B. 2-(4-Methyl-l-naphthalenyl)-4H-pyrido[3,2-ύT|[l,3]oxazin-4-one

Following the procedure for Step B in Example 1, a suspension of 3-amino-2- pyridinecarboxylic acid (414 mg, 3.0 mmol) in CH₂CI2 (10 mL) and diisopropylethylamine (1.25 mL, 7.2 mmol) was treated with 4-mefhyl-l-naphfhalenecarbonyl chloride, prepared from 4-methyl-l-naphthalenecarbonylic acid (590 mg, 3.17 mmol) with thionyl chloride (4.11 g, 35 mmol), and then with HATU (1.25 g, 3.3 mmol) in DMF (10 mL). The title compound was formed and directly used in Step C.

Step C. N-(Cyclobutylmethyl)-3-[[(4-methyl-l -naphthalenyl)carbonyl]amino]-2- pyridinecarboxamide

Following the procedure for Step C in Example 1, using 2-(4-methyl-l-naphfhalenyi)-4H- pyrido[3,2-cf][l,3]oxazin-4-one (130 mg, 0.45 mmol, see Step B for its preparation) and cyclobutylmethylamine (0.5 mL, 5.3 in MeOΗ, 2.5 mmol) provided the title compound (105 mg, 72%). 1H NMR (400 MHz, CD₃OD) δ 1.77 (m, 2 H), 1.87 (m, 2 H), 2.05 (m, 2 H), 2.60 (m, 1 H), 2.76 (s, 3 H), 3.37 (d, J=7.03 Hz, 2 H), 7.46 (d, J=7.23 Hz, 1 H), 7.59 (m, 3 H), 7.80 (d, J=7.23 Hz, 1 H), 8.14 (m, 1 H), 8.36 (dd, J=4.49, 1.37 Hz, 1 H), 8.46 (m, 1 H), 9.29 (dd, J=8.59, 1.37 Hz, 1 H). MS (ESI) (M+H)⁺ 374.0.

Example 3

N-(Cyclobutylmethyl)-3-[[(4-methoxy- 1 -naphthalenyl)carbonyl]amino]- 1 -oxide-2- pyridinecarboxamide

Step A. N-(Cyclobutylmethyl)-3-[[(4-methoxy-l-naphthalenyl)carbonyl]amino]-l-oxide-2- pyridinecarboxamide

Following the procedure for Step A in Example 1, N-(cyclobutylmethyl)-3-[[(4-methoxy- l-naphthalenyl)carbonyl]amino]-2-pyridinecarboxamide (87 mg, 0.224 mmol, see Steps B & C for its preparation) in CH₂Cl₂ (10 mL) was treated with 3-chloroperoxybenzoic acid (400 mg, 1.32 mmol) . The crude product was purified by reverse phase HPLC using 55- 80% MeCΝ/H₂O to provide the title compound as a white solid (11 mg, 12 %). 1H NMR (400 MHz, CD₃OD) δ 1.79 (m, 2 H), 1.88 (m, 2 H), 2.06 (m, 2 H), 2.61 (m, 1 H), 3.43 (d, J=7.03 Hz, 2 H), 4.08 (s, 3 H), 7.01 (d, J=8.01 Hz, 1 H), 7.56 (m, 3 H), 7.91 (d, J=8.20 Hz, 1 H), 8.18 (dd, J=6.35, 1.07 Hz, 1 H), 8.31 (m, 1 H,) 8.51 (d, J=8.20 Hz, 1 H), 9.04 (dd, J=8.79, 1.17 Hz, 1 H). MS (ESI) (M+H)⁺ 406.0.

Step B. 2-(4-Methoxy-l-naphthalenyl)-4H-pyrido[3,2-c ][l,3]oxazin-4-one

Following the procedure for Step B in Example 1, using 3-amino-2-pyridinecarboxylic acid (690 mg , 5.0 mmol), diisopropylethylamine (780 mg, 6.0 mmol), 4-methoxy-l- naphthalenecarbonyl chloride, prepared from 4-methoxy-l-naphfhoic acid (1.0 g, 5.0 mmol) and oxalyl chloride (5 mL, 2.0 M in CH₂C1₂, 10 mmol), and then HATU (2.28 g, 6.0 mmol) provided the title compound which was directly used in Step C.

Step C. N-(Cyclobutylmethyl)-3-[[(4-methoxy-l-naphthalenyl)carbonyl]amino]-2- pyridinecarboxamide

Following the procedure for Step C in Example 1, using 2-(4-mefhoxy-l-naphfhalenyl)- 4H-pyrido[3,2-c ][l,3]oxazin-4-one (120 mg, 0.40 mmol, see Step B for its preparation) and cyclobutylmethylamine (0.5 mL, 5.3 Min MeOΗ, 2.5 mmol) provided the title compound (87 mg, 56 %). ^]Η NMR (400 MHz, CD₃OD) δ 1.77 (m, 2 H), 1.88 (m, 2 H), 2.06 (m, 2 H), 2.61 (m, 1 H), 3.38 (d, J=7.23 Hz, 2 H), 4.08 (s, 3 H), 7.02 (d, J=8.20 Hz, 1 H), 7.56 (m, 3 H), 7.93 (d, J=8.01 Hz, 1 H), 8.32 (m, 2 H), 8.52 (m, 1 H), 9.27 (dd, J=8.59, 1.37 Hz, 1 H). MS (ESI) (M+H)⁺ 390.0.

Example 4

3-[(l-Naphthalenylcarbonyl)amino]-N-[(tetrahydro-2H-pyran-4-yl)methyl]-l-oxide-2- pyridinecarboxamide

Step A. 3-[(l-Naphthalenylcarbonyl)amino]-N-[(tetrahydro-2H-pyran-4-yl)methyl]-l- oxide-2-pyridinecarboxamide

Following the procedure for Step A in Example 1, 3-[(l-naphthalenylcarbonyl)amino]-N- [(tetrahydro-2H-pyran-4-yl)methyl]-2-pyridinecarboxamide (139 mg, 0.356 mmol, see Step B for its preparation) in CΗ₂C1₂ (10 mL) was treated with 3-chloroperoxybenzoic acid (323 mg, 1.07 mmol). The crude product was purified by MPLC using Hex/EtOAc (1 :1) on SiO₂ to provide the title compound as a white solid (100 mg, 63 %). 1H NMR (400 MHz, DMSO-D₆) δ 1.14 (m, 2 H), 1.52 (dd, J=12.79, 1.86 Hz, 2 H), 1.71 (m, 1 H), 3.16 (m, 4 H), 3.74 (dd, J=l 1.13, 3.71 Hz, 2 H), 7.60 (m, 4 H), 7.84 (d, J=7.23 Hz, 1 H), 8.02 (m, 1 H), 8.12 (d, J-8.20 Hz, 1 H), 8.26 (m, 1 H), 8.32 (m, 1 H), 8.72 (m, 1 H), 11.54 (s, 1 H), 12.81 (s, 1 H), 12.87 (s, 1 H). MS (ESI) (M+H)⁺ 406.0. Anal. (C, H, N) calcd for C₂₃H₂₃N₃O₄+0.1 HCl: C 67.53, H 5.69, N 10.27; found C 67.43, H 5.63, N 10.04.

Step B. 3-[(l-Naphthalenylcarbonyl)amino]-N-[(tetrahydro-2H-pyran-4-yl)methyl]-2- pyridinecarboxamide

Following the procedure for Step C in Example 1, using 2-(l-naphthalenyl)-4H-pyrido[3,2- ci][l,3]oxazin-4-one (122 mg, 0.446 mmol) and tetrahydro-2H-pyran-4-methanamine (62 mg, 0.535 mmol) provided the title compound (139 mg, 90 %). Η NMR (400 MHz, CDC1₃) δ 0.98 (m, 2H), 1.23 (m, 3H), 1.56 (m, 1H), 1.76 (m, 5H), 3.25 (t, J = 6.4 Hz, 2H), 7.54 (m, 4H), 7.90 (m, 2H), 7.98 (d, J = 8.0 Hz, 1H), 8.28 (dd, J = 8.4, 1.6 Hz, 1H), 8.53 (m, 2H), 9.41 (dd, J = 8.4, 0.8 Hz, 1H), 12.87 (s, 1H)., MS (ESI) (M+H)⁺ 390.2; Anal. Calcd for C₂3H₂₃N₃O₃: C, 70.93; H, 5.95; N, 10.79. Found: C, 70.82; H, 5.92; N, 10.64.

Example 5

3 - [[(4-Methy 1- 1 -naphthalenyl)carbony 1] amino] -N- [(tetrahy dro-2H-pyran-4-y l)me hyl] - 1 - oxide-2-pyridinecarboxamide

Step A. 3 - [ [(4-Methyl- 1 -naphthaleny l)carbony 1] amino] -N- [(tetrahy dro-2H-pyran-4- yl)mefhyl]- 1 -oxide-2-pyridinecarboxamide

Following the procedure for Step A in Example 1, 3-[[(4-methyl-l- naphthalenyl)carbonyl]amino]-N-[(tetrahydro-2H-pyran-4-yl)methyl]-2- pyridinecarboxamide (38.8 mg, 0.096 mmol, see Step B for its preparation) in CH₂C1₂ (10 mL) was treated with 3-chloroperoxybenzoic acid (220 mg, 0.73 mmol) . The crude product was purified by MPLC using EtOAc on Siθ2 to provide the title compound as a white solid (30 mg, 76 %). 1H NMR (400 MHz, CD₃OD) δ 1.30 (m, 2 H), 1.65 (d, J=13.08 Hz, 2 H), 1.83 (m, 1 H), 2.76 (s, 3 H), 3.34 (m, 4 H), 3.88 (dd, J=11.13, 3.51 Hz, 2 H), 7.44 (d, J=7.23 Hz, 1 H), 7.59 (m, 3 H), 7.77 (d, J=7.23 Hz, 1 H), 8.14 (m, 1 H), 8.21 (dd, J=6.44, 0.98 Hz, 1 H), 8.44 (m, 1 H), 8.99 (dd, J=8.79, 0.98 Hz, 1 H). MS (ESI) (M+H)⁺ 420.0. Anal. (C, H, N) calcd for C₂ H₂₅N₃O₄+0.3 H₂O: C 67.85, H 6.07, N 9.89; found C 67.87, H 5.88, N 9.80.

Step B. 3-[[(4-Methyl- l-naphthalenyl)carbonyl]amino]-N-[(tetrahydro-2H-pyran-4- yl)methyl]-2-pyridinecarboxamide

Following the procedure for Step C in Example 1, using 2-(4-methyl-l-naphfhalenyl)-4H- pyrido[3,2-<i][l,3]oxazin-4-one (108 mg, 0.375 mmol) and tetrahydro-2H-pyran-4- methanamine (122 mg, 1.06 mmol) provided the title compound (75 mg, 49%). 1H NMR (400 MHz, CD₃OD) δ 1.26 (dd, J=l 1.91, 4.49 Hz, 1 H), 1.33 (dd, J= 11.9, 4.5 Hz, 1 H), 1.63 (m, 2 H), 1.85 (m, 1 H), 2.76 (s, 3 H), 3.24 (d, J=7.03 Hz, 2 H), 3.36 (m, 2 H), 3.90 (dd, J=l 1.03, 3.22 Hz, 2 H), 7.45 (m, 1 H), 7.60 (m, 3 H), 7.79 (d, J=7.23 Hz, 1 H), 8.13 (m, 1 H), 8.36 (dd, J=4.49, 1.37 Hz, 1 H), 8.46 (m, 1 H), 9.28 (dd, J=8.59, 1.37 Hz, 1 H). MS (ESI) (M+H)⁺ 404.0. Anal. (C, H, N) calcd for C₂₄H₂₅N₃O₃+0.1 H₂O: C 71.13, H 6.27, N 10.37; found C 71.03, H 6.04, N 10.26.

Example 6

3-[[(4-Methoxy- 1 -naphthalenyl)carbonyl]amino]-N-[(tetrahydro-2H-pyran-4-yl)methyl]- 1 - oxide-2-pyridinecarboxamide

Step A. 3-[[(4-Mefhoxy-l-naphthalenyl)carbonyl]amino]-N-[(tetrahydro-2H-pyran-4- yl)methyl]- 1 -oxide-2-pyridinecarboxamide

Following the procedure for Step A in Example 1, 3-[[(4-methoxy-l- naphthalenyl)carbonyl]amino]-N-[(tetrahydro-2H-pyran-4-yl)methyl]-2- pyridinecarboxamide (78.8 mg, 0.188 mmol, see Step B for its preparation) in CH C.₂ (10 mL) was treated with 3-chloroperoxybenzoic acid (252 mg, 1.13 mmol) . The crude product was purified by reverse phase HPLC using 30-80% MeCN/H₂O to provide the title compound as a white solid (21 mg, 20 %). 1H NMR (400 MHz, CD₃OD) δ 1.32 (m, 2 H), 1.66 (m, J=12.69 Hz, 2 H), 1.85 (m, 1 H), 3.33 (m, 4 H), 3.88 (dd, J=11.13, 3.71 Hz, 2 H), 4.08 (s, 3 H), 7.01 (d, J=8.20 Hz, 1 H), 7.56 (m, 3 H), 7.91 (d, J=8.20 Hz, 1 H), 8.19 (d, J=6.44 Hz, 1 H), 8.31 (d, J=8.20 Hz, 1 H), 8.50 (d, J=8.40 Hz, 1 H), 8.99 (d, J=8.79 Hz, 1 H). MS (ESI) (M+H)⁺ 436.0.

Step B . 3 - [(4-Methoxy- 1 -naphthoy l)amino] -N-(tetrahy dro-2H-pyran-4-y lmefhyl)pyridine- 2-carboxamide

Following the procedure for Step C in Example 1, using 2-(4-mefhoxy-l-naphthyl)-4H- pyrido[3,2-c [l,3]oxazin-4-one (120 mg, 0.4 mmol), and tetrahydro-2H-pyran-4- methanamine (210 mg, 1.8 mmol) provided the title compound (81 mg, 48 %). 1H ΝMR (400 MHz, CD₃OD) δ 1.31 (m, 2 H), 1.64 (dd, J=13.08, 1.17 Hz, 2 H), 1.87 (m, J=7.62, 3.51 Hz, 1 H), 3.26 (m, J=6.83 Hz, 2 H), 3.36 (m, 2 H), 3.91 (dd, J=11.72, 3.51 Hz, 2 H), 4.08 (s, 3 H), 7.01 (d, J=8.20 Hz, 1 H), 7.56 (m, 3 H), 7.93 (d, J=8.01 Hz, 1 H), 8.33 (m, 2 H), 8.51 (d, J=8.59 Hz, 1 H), 9.26 (m, 1 H). MS (ESI) (M+H)⁺ 420.0

Example 7 N-(Cyclohexylmethyl)-3-[(l-naphthalenylcarbonyl)amino]-l-oxide-2-pyridinecarboxamide

Step A. N-(Cyclohexylmethyl)-3-[( 1 -naphthalenylcarbonyl)amino]- 1 -oxide-2- pyridinecarboxamide

Following the procedure for Step A in Example 1, N-(cyclohexylmethyl)-3-[(l- naphthalenylcarbonyl)amino]- 2-pyridinecarboxamide (172 mg, 0.45 mmol, see Step B for its preparation) in CH₂CI₂ (10 mL) was treated with 3-chloroperoxybenzoic acid (295 mg, 1.3 mmol) . The crude product was purified by reverse phase HPLC using 30-80% MeCΝ/Η₂O to provide the title compound as a white solid (161 mg, 89 %). 1H NMR (400 MHz, CD₃OD) δ 1.00 (m, 2 H), 1.19 (m, 3 H), 1.56 (m, 1 H), 1.70 (m, 5 H), 3.23 (d, J=6.64 Hz, 2 H), 7.58 (m, 4 H), 7.88 (dd, J=7.13, 1.07 Hz, 1 H), 7.96 (m, 1 H), 8.07 (d, J=8.20 Hz, 1 H), 8.21 (d, J=6.44 Hz, 1 H), 8.42 (m, 1 H), 9.03 (d, J=8.79 Hz, 1 H). MS (ESI) (M+H)⁺ 404.0.

Step B . N-(Cyclohexylmethyl)-3 - [( 1 -naphthalenylcarbonyl)amino]-2-pyridinecarboxamide

Following the procedure for Step C in Example 1, using 2-(l-naphthalenyl)-4H-pyrido[3,2- ][l,3]oxazin-4-one (129 mg, 0.47 mmol), and cyclohexanemethylamine (261 mg, 2.3 mmol) provided the title compound (172 mg, 95 %). 1H NMR (400 MHz, CD₃OD) δ 0.90- 1.00 (m, 2 H), 1.13-1.28 (m, 3 H), 1.52-1.75 (m, 6 H), 3.16 (d, J=6.83 Hz, 2 H), 7.55-7.61 (m, 4 H), 7.88-7.90 (m, 1 H), 7.94-7.96 (m, 1 H), 8.05-8.07 (m, 1 H), 8.36 (dd, J=4.49, 1.56 Hz, 1 H), 8.41-8.43 (m, 1 H), 9.29 (dd, J=8.59, 1.37 Hz, 1 H). MS (ESI) (M+H)⁺ 388.0.

Example 8

N-(Cyclohexylmethyl)-3-[(4-mefhyl-l-naphthalenylcarbonyl)amino]-l-oxide-2- pyridinecarboxamide

Step A. N-(Cyclohexylmefhyl)-3-[(4-methyl- 1 -naphthalenylcarbonyl)amino]- 1 -oxide-2- pyridinecarboxamide

Following the procedure for Step A in Example 1, N-(cyclohexylmethyl)-3-[(4-methyl-l- naphfhalenylcarbonyl)amino]- 2-pyridinecarboxamide (66 mg, 0.165 mmol, see Step B & C for its preparation) in CH₂CI₂ (10 mL) was treated with 3-chloroperoxybenzoic acid (111.0 mg, 0.495 mmol) . The crude product was purified by reverse phase HPLC using 30-80% MeCN/H₂O to provide the title compound as a white solid (56 mg, 81 %). 1H NMR (400 MHz, CD₃OD) δ 0.91 - 1.06 (m, 2 H), 1.12 - 1.32 (m, 3 H), 1.48 - 1.62 (m, 1 H), 1.60 - 1.82 (m, 5 H), 2.75 (s, 3 H), 3.23 (d, J=6.83 Hz, 2 H), 7.44 (d, J=7.22 Hz, 1 H), 7.53 - 7.64 (m, 3 H), 7.77 (d, J=7.23 Hz, 1 H), 8.08 - 8.15 (m, 1 H), 8.19 (dd, J=6.44, 1.17 Hz, 1 H), 8.41 - 8.47 (m, 1 H), 9.02 (dd, J=8.79, 1.17 Hz, 1 H),. MS (ESI) (M+H)⁺ 418.0

Step B. 3-Amino-N-(cyclohexylmethyl)pyridine-2-carboxamide

3-Aminopyridine-2-carboxylic acid (138 mg, 1.0 mmol) was added to a solution of cyclohexane me hylamine (226 mg, 2. 0 mmol) and DIPEA (259 mg, 0.35 mmol) in DMF (5 mL). After stirring for 30 min, HATU (456 mg, 1.2 mmol) was added at 0 °C. The resulting mixture was stirred overnight at room temperature, quenched with water (5 ml), concentrated to a small volume, diluted with EtOAc (100 mL), washed with water (2x5 mL) and brine (5 mL), then dried with sodium sulphate. After filtration and concentration, the crude product was purified by MPLC using Hex/EtOAc (1 : 1) on Siθ₂ to provide the title compound (124 mg, 53 %). 1H NMR (400 MHz, CDC1₃) δ 0.93 - 1.07 (m, 2 H), 1.13 - 1.32 (m, 3 H), 1.51 - 1.70 (m, 2 H), 1.70 - 1.86 (m, 4 H), 3.26 (t, J=6.64 Hz, 2 H), 6.00 (s, 2 H), 7.00 (dd, J=8.40, 1.37 Hz, 1 H), 7.15 (dd, J=8.40, 4.30 Hz, 1 H), 7.85 (dd, J=4.30, 1.37 Hz, 1 H), 8.22 (s, 1 H). (MS (ESI) (M+H)⁺ 233.89.

Step C. N-(Cyclohexylmefhyl)-3-[(4-methyl-l-naphfhalenylcarbonyl)amino]-2- pyridinecarboxamide

4-Methyl-l-naphthalenecarbonyl chloride (80 mg, 0.39 mmol) was added to a solution of 3-amino-N-(cyclohexylmethyl)pyridine-2-carboxamide (61 mg, 0.26 mmol) and DMAP (64 mg, 0.52 mmol) in CH₂CI₂ (10 mL) at 0 °C. The mixture was stirred overnight at room temperature, quenched with saturated NaHCO₃ (5 mL), and extracted with EtOAc (3x50 mL). The combined oranic phase was washed with brine (2x10 mL) and dried with sodium sulphate. After filtration and concentration, the crude products were purifed by MPLC using hexane/EtOAc (4:1) on Siθ₂ to provide the title compound as a white solid (96 mg, 92 %). 1H NMR (400 MHz, CD₃OD) δ 0.88 - 1.05 (m, 2 H), 1.09 - 1.34 (m, 3 H), 1.52 - 1.68 (m, 2 H), 1.68 - 1.81 (m, 4 H), 2.76 (s, 3 H), 3.18 (d, J=6.83 Hz, 2 H), 7.39 - 7.50 (m, 1 H), 7.54 - 7.65 (m, 3 H), 7.80 (d, J=7.23 Hz, 1 H), 8.06 - 8.18 (m, 1 H), 8.36 (dd, J=4.49, 1.56 Hz, 1 H) ,8.43 - 8.50 (m, 1 H), 9.29 (dd, J=8.59, 1.56 Hz, 1 H). MS (ESI) (M+H)⁺ 402.0

Example 9

N-(Cyclohexylmefhyl)-3-[(4-methoxy-l-naphthalenylcarbonyl)amino]-l-oxide-2- pyridinecarboxamide

Step A. N-(Cyclohexylmethyl)-3-[(4-methoxy- 1 -naphthalenylcarbonyl)amino]- 1 -oxide-2- pyridinecarboxamide

Following the procedure for Step A in Example 1, N-(cyclohexylmethyl)-3-[(4-methoxy-l- naphthalenylcarbonyl)amino]-2-pyridinecarboxamide (76 mg, 0.18 mmol, see Step B for its preparation) in CH2CI2 (10 mL) was treated with 3-chloroperoxybenzoic acid (122 mg, 0.543 mmol) . The crude product was purified by reverse phase HPLC using 30-80% MeCN/H₂O to provide the title compound as a white solid (15 mg, 19 %). 1H NMR (400 MHz, CD₃OD) δ 0.93 - 1.07 (m, 2 H), 1.13 - 1.30 (m, 3 H), 1.51 - 1.60 (m, 1 H), 1.62 - 1.82 (m, 5 H), 3.25 (d, J=6.64 Hz, 2 H), 4.08 (s, 3 H), 7.01 (d, J=8.20 Hz, 1 H), 7.47 - 7.65 (m, 3 H), 7.91 (d, J=8.20 Hz, 1 H), 8.18 (dd, J=6.44, 0.98 Hz, 1 H), 8.27 - 8.35 (m, 1 H), 8.48 - 8.56 (m, 1 H), 9.02 (dd, J=8.89, 1.07 Hz, 1 H). MS (ESI) (M+H)⁺ 434.0.

Step B. N-(Cyclohexylmethyl)-3-[(4-methoxy-l -naphthalenylcarbonyl)amino]-2- pyridinecarboxamide

Following the procedure for Step C in Example 8, 3-amino-N-(cyclohexylmethyl)pyridine- 2-carboxamide (60 mg, 0.26 mmol) was treated with 4-methoxy-l-naphthalenecarbonyl chloride (71 mg, 0.32 mmol) in CH₂C1₂ (10 mL) in the presence of DMAP (64 mg, 0.52 mmol). The crude products were purifed by MPLC using hexane/EtOAc (4:1) on Siθ₂ to provide the title compound as a white solid (76 mg, 70 %). 1H NMR (400 MHz, CD₃OD) δ 0.90 - 1.04 (m, 2 H), 1.14 - 1.34 (m, 3 H), 1.60 (d, J=3.51 Hz, 2 H), 1.69 - 1.81 (m, 4 H), 3.20 (d, J=7.03 Hz, 2 H), 4.08 (s, 3 H), 7.02 (d, J=8.20 Hz, 1 H), 7.44 - 7.64 (m, 3 H, 7.93 (d, J=8.01 Hz, 1 H), 8.28 - 8.40 (m, 2 H), 8.51 (d, J=8.40 Hz, 1 H), 9.27 (dd, J=8.59, 1.37 Hz, 1 H). MS (ESI) (M+H)⁺ 418.0.

Example 10

N-(Cyclohexylmethyl)-3-[(4-methoxy-l-naphthalenylcarbonyl)amino]-l-oxide-2- pyridinecarboxamide

Following the procedure for Step A in Example 1, N-(cyclohexylmethyι)-3-[(4-methoxy-l- naphthalenylcarbonyl)amino]-2-pyridinecarboxamide (76 mg, 0.18 mmol, see Step B for its preparation) in CH₂CI₂ (10 mL) was treated with 3-chloroperoxybenzoic acid (122 mg, 0.543 mmol) . The crude product was purified by reverse phase HPLC using 30-80% MeCN/H₂O to provide the title compound as a white solid (15 mg, 19 %). Η NMR (400 MHz, CD₃OD) δ 0.93 - 1.07 (m, 2 H), 1.13 - 1.30 (m, 3 H), 1.51 - 1.60 (m, 1 H), 1.62 - 1.82 (m, 5 H), 3.25 (d, J=6.64 Hz, 2 H), 4.08 (s, 3 H), 7.01 (d, J=8.20 Hz, 1 H), 7.47 - 7.65 (m, 3 H), 7.91 (d, J=8.20 Hz, 1 H), 8.18 (dd, J=6.44, 0.98 Hz, 1 H), 8.27 - 8.35 (m, 1 H), 8.48 - 8.56 (m, 1 H), 9.02 (dd, J=8.89, 1.07 Hz, 1 H). MS (ESI) (M+H)⁺ 434.0. Anal. Calcd for C₂₅H₂₇N₃O₄ + 0.1 MeOH (436.71): C, 69.03; H, 6.32; N, 9.62. Found: C, 69.04; H 6.25; N, 9.45. Step B. N-(Cyclohexylmethyl)-3-[(4-methoxy-l-naphthalenylcarbonyl)amino]-2- pyridinecarboxamide

Following the procedure for Step C in Example 9, 3-amino-N-(cyclohexylmethyl)pyridine- 2-carboxamide (60 mg, 0.26 mmol) was treated with 4-methoxy-l-naphthalenecarbonyl chloride (71 mg, 0.32 mmol) in CH₂C1₂ (10 mL) in the presence of DMAP (64 mg, 0.52 mmol). The crude products were purifed by MPLC on silica gel using hexane/EtOAc (4:1) to provide the title compound as a white solid (76 mg, 70 %). Η NMR (400 MHz, CD₃OD) δ 0.90 - 1.04 (m, 2 H), 1.14 - 1.34 (m, 3 H), 1.60 (d, J=3.51 Hz, 2 H), 1.69 - 1.81 (m, 4 H), 3.20 (d, J=7.03 Hz, 2 H), 4.08 (s, 3 H), 7.02 (d, J=8.20 Hz, 1 H), 7.44 - 7.64 (m, 3 H, 7.93 (d, J=8.01 Hz, 1 H), 8.28 - 8.40 (m, 2 H), 8.51 (d, J=8.40 Hz, 1 H), 9.27 (dd, J=8.59, 1.37 Hz, 1 H). MS (ESI) (M+H)⁺ 418.0.

Claims

What is claimed is:

1. A compound of formula I or a pharmaceutically acceptable salt thereof, diastereomers, enantiomers, or mixtures thereof:

I wherein: m is selected from 0, 1 and 2; n is selected from 0, 1, 2, 3, 4 and 5; R¹ is independently selected from halogen, cyano, amino, nitro, Ci-δalkylamino, diCi-_όalkylamino, acetylamino, hydroxyl, Ci-βalkoxy,

halogenated Cι_-6alkoxy,

Cι_-6alkenyl, and halogenated Ci-βalkyl; R is selected from C_6-ioaryl and C2-ιoheterocyclyl; wherein said Cό-ioaryl and C₂- _loheterocyclyl used in defining R² is optionally substituted by one or more groups selected from halogen, halogenated Cι_-6alkyl, Ci-βalkyl, cyano, nitro, Cι_-6alkoxy, halogenated .

₆alkoxy, hydroxy, hydroxy-Cι.₆alkyl, amino, Ci-_όalkoxy-Ci-ealkyl, Cι_-6alkylcarbonyl, Ci. _όalkoxycarbonyl, Cι.₆alkylamino, diCi-_όalkyl-amino, amino-Cι-6alkyl, C₃.₆cycloalkyl, C₂. όheteroaryl, heteroaryl-Cι_-6alkyl, C_δ-ioaryl, and C_6-ιoaryl-Cι.₆alkyl; and R³ is selected from hydrogen and Ci-βalkyl; R⁴ is selected from Cι.₆alkyl, C₃. ₇cycloalkyl, C_4-7cycloalkenyl, C_ό-io ryl, C₂-₆heterocyclyl-amino, C₂-₆heterocyclyloxy- amino and C2-₆heterocyclyl; wherein said Cι.₆alkyl, C_3-7cycloalkyl, C_4-7cycloalkenyl, C_6- loaryl, C2-6heterocyclyl-amino, C₂-₆heterocyclyloxy-amino and C2_-6heterocyclyl used in defining R⁴ is optionally substituted by one or more groups selected from halogen, halogenated Ci^alkyl, Ci-βalkyl, cyano, nitro, Cι.₆alkoxy, halogenated Cι.₆alk;oxy, hydroxy, hydroxy-Cι.₆alkyl, amino, Cι.₆alko y-Cι.₆alkyl, Cι_-6alkylcarbonyl, Ci.

₆alkoxycarbonyl, Cι.₆alkylamino, diCι.₆alkyl-amino, amino-Cι_-6alkyl, C_3-6cycloalkyl, C₂- ₆heteroaryl, heteroaryl-Cι_-6alkyl, C_ό-io ryl, and Cβ-ioaryl-Ci-όalkyl; or

is C₂. _loheterocyclyl, which is optionally substituted by one or more groups selected from halogen, halogen substituted Cι_-6alkyl, C^ancyl, cyano, nitro, Cι_-6alkoxy, halogenated . ₆alkoxy, hydroxy, hydroxy-Cι.₆alkyl, amino, Cι.₆alkoxy-Cι-6alkyl, Cι.₆alkylcarbonyl, C . ₆alkoxycarbonyl, Cι.₆alkylamino, diCi-ealkyl-amino, amino-Cι_-6alkyl, C_3-6cycloalkyl, C₂- ₆heteroaryl, heteroaryl-Cι.₆alkyl, Cβ-ioaryl, and C₆-ioaryl-Ci.6a.kyl.

2. A compound as claimed in claim 1, wherein m is selected from 0, 1 and 2; n is selected from 0, 1, 2, 3 and 4; R¹ is independently selected from halogen, cyano, amino, nitro, acetylamino, hydroxyl, Cι_-3alkoxy, Cι_-3alkyl, halogenated Cι- alkoxy, and halogenated Cι_-3alkyl; R² is selected from C_6-ιoaryl and C₂-ιoheterocyclyl, wherein said C_ό-ioaryl and C2- loheterocyclyl used in defining R² is optionally substituted by one or more groups selected from halogen, halogenated Cι_-3alkyl, Cι_-3alkyl, nitro, Cι_-3alkoxy, halogenated Cι_-3alkoxy, hydroxy, hydroxy-Ci_-3alkyl, amino, Cι.₃alkoxy-Cι.₃alkyl, C₂-₅heterocyclyl-Cι_-3alkyl, d. όalkoxycarbonyl, Cι_-3alkylamino, diCι_-3alkyl-amino, and amino-Cι_-3alkyl; and R³ is selected from hydrogen and Cι-6 alkyl; R⁴ is selected from Ci.₆alkyl, C₃. ^• _/cycloalkyl, C₂-₆heterocyclyl-amino, C_2-6heterocyclyloxy-amino, and C_2-6 heterocyclyl; wherein said Cι.₆alkyl, C_3- cycloalkyl, C₂-₆heterocyclyl-amino, C₂-6heterocyclyloxy-amino, and C2-₆ heterocyclyl used in defining R⁴ is optionally substituted by one or more groups selected from halogen, halogenated Cι. alkyl, Cι_-3alkyl, nitro, Cι_-3alkoxy, halogenated Ci. ₃alkoxy, hydroxy, hydroxy-Cι.₃alkyl, amino, Cι_-3alkoxy-Cι_-3alkyl, Cι.₆alkoxycarbonyl, Ci. / (^CH ₂)-R

₃alkylamino, diCι_-3alkyl-amino, and amino-Cι.₃alkyl; or R ^³ is selected from azepanyl, pyrrolyl, pyrrolinyl, pyrrolidinyl, imidazolyl, imidazolidinyl, pyrazolyl, pyrazolinyl, pyrazolidinyl, isoxazolidinyl, triazolyl, morpholinyl, piperidinyl, fhiomorpholinyl, pyridazinyl, piperazinyl, triazinyl or l,4-dioxa-8-azaspiro[4.5]decan-8-yl; wherein said azepanyl, pyrrolyl, pyrrolinyl, pyrrolidinyl, imidazolyl, imidazolidinyl, pyrazolyl, pyrazolinyl, pyrazolidinyl, isoxazolidinyl, trazolyl, morpholinyl, piperidinyl, thiomorpholinyl, piperazinyl, triazinyl and l,4-dioxa-8-azaspiro[4.5]decan-8-yl are optionally substituted by one or more groups selected from halogen, halogenated Cι.₃alkyl, Cι_-3alkyl, nitro, Cι.₃alkoxy, halogenated Cι_-3alkoxy, hydroxy, hydroxy-Cι. alkyl, amino, Cι.₃alkoxy-Cι.₃alkyl, Cι_-6alkoxycarbonyl, Cι_-3alkylamino, diCι- alkyl-amino, and amino- Cι_-3alkyl.

3. A compound as claimed in claim 1, wherein m is selected from 0 and 1 ; n is selected from 0, 1, 2, 3 and 4; R¹ is independently selected from halogen, amino, nitro, acetylamino, hydroxyl, . alkoxy, Cι.₃alkyl, halogenated Cι. alkoxy, and halogenated Cι_-3alkyl; R is selected from phenyl, naphthyl, pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, thienyl, furyl, pyrrolyl, imidazolyl, thiazolyl, oxazolyl, pyrazolyl, isothiazolyl, isoxazolyl, 1,2,3-triazolyl, tetrazolyl, 1,2,3-thiadiazolyl, 1,2,3-oxadiazolyl, 1,2,4-triazolyl, 1,2,4- thiadiazolyl, 1,2,4-oxadiazolyl, 1,3,4-triazolyl, 1,3,4-thiadiazolyl, and 1,3,4 oxadiazolyl, indolyl, indolinyl, quinolinyl, tetrahydroquinolinyl, isoquinolinyl, tetrahydroisoquinolinyl, 1,4-benzodioxanyl, coumarin, dihydrocoumarinyl, 2,3-dihydrobenzofuranyl, 1,2- benzisoxazolyl, 1,3-benzodioxolyl, 2,3-dihydro-l,4-benzodioxinyl, 3,4-dihydro-2H-l,5- benzodioxepinyl, 4H-l,3-benzodioxinyl, benzofuranyl, benzothiophenyl, benzoxazolyl, benzthiazolyl, benzimidazolyl, benztriazolyl, thioxanthinyl, carbazolyl, carbolinyl, acridinyl, pyrolizidinyl, and quinolizidinyl that are optionally substituted by one or more groups selected from halogen, hydroxy, methyl, methoxy, amino, trifluoromethyl, trifluoromethoxy, methoxyme hyl, lH-l,2,3-triazolylmethyl and lH-pyrazolylmethyl; R is selected from hydrogen and Cι.₆ alkyl; and R⁴ is selected from

cyclopentylhydroxyamino, O-cyclobutylhydroxyamino, O-cyclopropylhydroxyamino, and Cι.₃alkyl that are optionally substituted by one or more groups selected from halogen, amino, aminomethyl, 2-aminoethyl, hydroxy, hydroxylmethyl, methyl and ethyl.

4. A compound as claimed in claim 3, wherein R is selected from

that are optionally substituted with one or more groups selected from halogen, methyl, methoxy, hydroxyl, methoxymethyl, lH-l,2,3-triazolylmethyl and 1H-1,2- diazolylme hyl.

5. A compound as claimed in claim 1, wherein m is 1; n is selected from 0, 1, 2, and 3; R¹ is independently selected from halogen, amino, nitro, acetylamino, hydroxyl, . ₃alkoxy, Cι.₃alkyl, halogenated Cι_-3alkoxy, and halogenated Cι.₃alkyl; R² is selected from phenyl, naphthyl, pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, thienyl, furyl, pyrrolyl, imidazolyl, thiazolyl, oxazolyl, pyrazolyl, isothiazolyl, isoxazolyl, 1,2,3-triazolyl, tetrazolyl, 1,2,3-thiadiazolyl, 1,2,3-oxadiazolyl, 1,2,4-triazolyl, 1,2,4- thiadiazolyl, 1,2,4-oxadiazolyl, 1,3,4-triazolyl, 1,3,4-thiadiazolyl, and 1,3,4 oxadiazolyl, indolyl, indolinyl, quinolinyl, tetrahydroquinolinyl, isoquinolinyl, tetrahydroisoquinolinyl, 1,4-benzodioxanyl, coumarin, dihydrocoumarinyl, 2,3-dihydrobenzofuranyl, 1,2- benzisoxazolyl, 1,3-benzodioxolyl, 2,3-dihydro-l,4-benzodioxinyl, 3,4-dihydro-2Η-l,5- benzodioxepinyl, 4H-l,3-benzodioxinyl, benzofuranyl, benzothiophenyl, benzoxazolyl, benzthiazolyl, benzimidazolyl, benztriazolyl, thioxanthinyl, carbazolyl, carbolinyl, acridinyl, pyrolizidinyl, and quinolizidinyl that are optionally substituted by one or more groups selected from halogen, hydroxy, methyl, methoxy, amino, trifluoromefhyl, trifluoromethoxy, methoxymethyl, lH-l,2,3-triazolylmefhyl, IH-pyrazolylmethyl; and

selected from azetidinyl, azepanyl, isoxazolidinyl, morpholinyl, piperazinyl, piperidinyl, pyrrolidinyl, and l,4-dioxa-8-azaspiro[4.5]decan-8- yl that were optionally substituted with one or more groups selected from halogen, cyano, nitro, methyl, ethyl, hydroxy, hydroxy-methyl, hydroxy-ethyl, amino-methyl, amino-ethyl, methoxy-methyl, methoxy-phenyl, ethoxycarbonyl, tert-butoxycarbonyl, diphenyl-methyl, morpholinyl-eth-2-yl, piperidinyl-methyl and pyridinyl.

6. A compound as claimed in claim 5,

selected from

7. A compound as claimed in claim 5 or 6, R² is selected from

that are optionally substituted with one or more groups selected from halogen, methyl, methoxy, hydroxyl, methoxymethyl, lH-l,2,3-triazolylmethyl and IH- pyrazolylmethyl.

A compound as claimed in any one of claims 1-7, wherein R² is selected from

optionally substituted with one or more groups selected from halogen, methyl, methoxy, hydroxyl, methoxymethyl, lH-l,2,3-triazolylmefhyl and IH-pyrazolylmethyl.

9. A compound selected from:

N-(Cyclobutylmethyl)-3-[(l-naphthalenylcarbonyl)amino]-l-oxide-2- pyridinecarboxamide; N-(Cyclobutylmethyl)-3-[[(4-methyl-l-naphthalenyl)carbonyl]amino]-l-oxide-2- pyridihecarboxamide;

N-(Cyclobutylmethyl)-3-[[(4-methoxy-l-naphthalenyl)carbonyl]amino]-l-oxide-2- pyridinecarboxamide;

3-[(l-Naphthalenylcarbonyl)amino]-N-[(tetrahydro-2H-pyran-4-yl)methyl]-l-oxide-2- pyridinecarboxamide;

3-[[(4-Methyl-l-naphthalenyl)carbonyl]amino]-N-[(tetrahydro-2Η-pyran-4-yl)methyl]-l- oxide-2-pyridinecarboxamide;

3-[[(4-Methoxy- 1 -naphthalenyl)carbonyl]amino]-N-[(tetrahydro-2H-pyran-4-yl)methyl]- 1 - oxide-2 -pyridinecarboxamide; N-(Cyclohexylmethyl)-3 -[( 1 -naphthalenylcarbonyl)amino]- 1 -oxide-2- pyridinecarboxamide;

N-(Cyclohexylmethyl)-3 - [(4-mefhyl- 1 -naphthalenylcarbonyl)amino]- 1 -oxide-2- pyridinecarboxamide;

N-(Cyclohexylmethyl)-3-[(4-methoxy- 1 -naphthalenylcarbonyl)amino]- 1 -oxide-2- pyridinecarboxamide;

N-(Cyclohexylmethyl)-3-[(4-methoxy- 1 -naphthalenylcarbonyl)amino]- 1 -oxide-2- pyridinecarboxamide; and pharmaceutically acceptable salts thereof.

10. A compound according to any one of claims 1-9 for use as a medicament.

11. The use of a compound according to any one of claims 1-9 in the manufacture of a medicament for the therapy of pain.

12. The use of a compound according to any one of claims 1-9 in the manufacture of a medicament for the therapy of functional gastrointestinal disorders.

13. The use of a compound according to any one of claims 1 -9 in the manufacture of a medicament for the treatment of irritable bowel syndrome.

14. The use of a compound according to any one of claims 1-9 in the manufacture of a medicament for the treatment of anxiety, cancer, multiple sclerosis, Parkinson's disease,

Huntington's chorea, Alzheimer's disease, and cardiavascular disorders.

15. A pharmaceutical composition comprising a compound according to any one of claims 1-9 and a pharmaceutically acceptable carrier.

16. A method for the therapy of functional gastrointestinal disorders in a warm-blooded animal, comprising the step of administering to said animal in need of such therapy a therapeutically effective amount of a compound according to any one of claims 1-9.

17. A method for the therapy of irritable bowel syndrome in a warm-blooded animal, comprising the step of administering to said animal in need of such therapy a therapeutically effective amount of a compound according to any one of claims 1-9.

18. A method for preparing a compound of formula I,

I comprising the step of reacting a compound of formula II,

II with mCPB A, in the presence of a solvent such as CH₂CI₂, wherein: m is selected from 0, 1 and 2; n is selected from 0, 1, 2, 3, 4 and 5; R¹ is independently selected from halogen, cyano, amino, nitro, Cι.₆alkylamino, diCι_-6alkylamino, acetylamino, hydroxyl, Ci-βalkoxy, Cι_-6alkyl, halogenated Cu_όalkoxy, ^alkenyl, and halogenated C_1-6alkyl; R² is selected from C_6-ιoaryl and C₂-ιoheterocyclyl; wherein said C_6-1oaryl and C₂- _loheterocyclyl used in defining R² is optionally substituted by one or more groups selecte from halogen, halogenated Cι.₆alkyl, Cι_-6alkyl, cyano, nitro, Cι_-6alkoxy, halogenated C_\. ₆alkoxy, hydroxy, hydroxy-Ci-δalkyl, amino, Cι_-6alkoxy-Cι.₆alkyl, Cι_-6alkylcarbonyl, Ci. ₆alkoxycarbonyl, Ci-ealkylamino, diCi-_όalkyl-amino, amino-Cι_-6alkyl, C₃.₆cycloalkyl, C₂. _όheteroaryl, heteroaryl-Ci_-6alkyl, Cβ-ioaryl, and C_ό-ioaryl-Ci-ealkyl; and R³ is selected from hydrogen and Cι_-6alkyl; R⁴ is selected from Cι_-6alkyl, C₃. cycloalkyl, C_4-7cycloalkenyl, C_6-ιoaryl, C_2-6heterocyclyl-amino, C_2-6heterocyciyloxy- amino and C₂-₆heterocyclyl; wherein said Cι.₆alkyl, C_3-7cycloalkyl, C_4-7cycloalkenyl, C₆. _loaryl, C₂-₆heterocyclyl-amino, C₂-₆heterocyclyloxy-amino and C₂-₆heterocyclyl used in defining R⁴ is optionally substituted by one or more groups selected from halogen, halogenated Ci-βalkyl, C^aUcyl, cyano, nitro, Cι.₆alkoxy, halogenated Cι.₆alkoxy, hydroxy, hydroxy-Ci-_όalkyl, amino, Cι.₆alkoxy-Cι gall y 1, Ci-βalkylcarbonyl, Ci. ₆alkoxycarbonyl, Cι.₆alkylamino, diCi-όalkyl-amino, amino-Cι.₆alkyl, C₃.₆cycloalkyl, C₂- / (CH₂)-R*

_όheteroaryl, heteroaryl-Ci-βalkyl, Cβ-ioaryl, and Ca-io ryl-Ci-_όalkyl; or R° is C2- loheterocyclyl, which is optionally substituted by one or more groups selected from halogen, halogen substituted C^aUcyl, C^aUcyl, cyano, nitro, Cι_-6alkoxy, halogenated Ci ₆alkoxy, hydroxy, hydroxy-Cι-₆alkyl, amino, d-βalkoxy-Ci-όalkyl, Cι.₆alkylcarbonyl, C_\. ₆alkoxycarbonyl, Cι_-6alkylamino, diCι.6alkyl-amino, amino-Cι.6alkyl, C_3-6cycloalkyl, d- ₆heteroaryl, heteroaryl-Ci_-6alkyl, C_6-ιoaryl, and C_6-ιoaryl-Cι_-6alkyl.