AU2001282162A1 - Inhibitors of copper-containing amine oxidases - Google Patents

Description

Inhibitors Of Copper-Containing Amine Oxidases

Field of the Invention

The present invention is in the field of medicinal chemistry and is directed to 1,3,4-oxadiazine compounds and their use as inhibitors of copper-containing amine oxidases (E.C. 1.4.3.6) and enzymes of significant identity thereto. The compounds of the present invention have therapeutic utility as drugs to treat diseases including but not limited to a number of inflammatory conditions and diseases (in particular chronic inflammatory conditions or diseases such as chronic arthritis, inflammatory bowel diseases, and chronic skin dermatoses) as well as diseases related to carbohydrate metabolism and to aberrations in adipocyte differentiation or function and smooth muscle cell function.

Background of the Invention

NAP-1 is a human endothelial cell adhesion molecule that has several unique properties that distinguish it from the other inflammation-related adhesion molecules and these are described as follows. NAP-1 has a unique and restricted expression pattern and mediates lymphocyte binding to vascular endothelium

(Salmi, M., and Jalkanen, S., Science 257:1407-1409 (1992)). Inflammation induces upregulation of NAP-1 to the surface of vascular endothelial cells mediating leukocyte entry to skin, gut and inflamed synovium (Salmi, M., and

Jalkanen, S., Science 257:1407-1409 (1992); Salmi, M., et al, J. Exp. Med

178:2255-2260 (1993); Arvillomi, A, etal.,Eur. J. Immunol. 25:825-833 (1996);

Salmi, M., et al, J. Clin. Invest. 99:2165-2172 (1997)). NAP-1 is rapidly translocated onto vascular endothelium at sites of inflammation. (Salmi, M., and Jalkanen, S., J. Exp. Med. 183:569-519 (1996); J. Exp. Med. 755:589-600

(1997)). Lastly, NAP-1 has a catalytic extracellular domain with a monoamine oxidase activity (Smith, D.J., etal, J. Exp. Med. 188:17-27 (1998)). The cloning and sequencing of the human NAP-1 cDΝA revealed that it encodes a transmembrane protein with homology to a class of enzymes called the copper-containing amine oxidases (E.G. 1.4.3.6). Enzyme assays have shown that VAP-1 possesses a monoamine oxidase (MAO) activity which is present in the extracellular domain of the protein (Smith, D.J., et al, J. Exp. Med. 188:11-21 (1998)). Thus, NAP-1 is an ecto-enzyme. Analysis of the NAP-1 MAO activity showed that NAP-1 belongs to the class of membrane-bound MAO's termed semicarbazide-sensitive amine oxidases (SSAO). These are distinguished from the widely distributed mitochondrial MAO-A and B flavoproteins by amino acid sequence, cofactor, substrate specificity and sensitivity to certain inhibitors. However, certain substrates and inhibitors are common to both SSAO and MAO activities. The mammalian S SAO' s can metabolize various monoamines produced endogenously or absorbed as dietary or xenobiotic substances. They act principally on primary aliphatic or aromatic monoamines such as methylamine or benzylamine (Lyles, G.A., Int. J. Biochem. Cell Biol. 28:259-214 (1996)). Thus, NAP-1 located on the vascular endothelial cell surface can act on circulating primary monoamines with the following reaction pathway.

KΝH.2 + O₂ + H₂O ► RCHO + H₂O₂ + ϊ₃

In human clinical tissue samples, expression of NAP- 1 is induced at sites of inflammation. This increased level of NAP-1 can lead to increased production of H₂O₂ generated from the action of the NAP-1 SSAO extracellular domain on monoamines present in the blood. This generation of H₂O₂ in the localised environment of the endothelial cell can initiate other cellular events. H₂O₂ is a known signalling molecule that can upregulate other adhesion molecules and this increased adhesion molecule expression may lead to enhanced leukocyte trafficking into areas in which NAP-1 is expressed. Preliminary data supporting this has been obtained using an in vitro model in which increased E-Selectin, NCAM-1 and ICAM-1 expression on cultured human umbilical vein endothelial cells (HUNEC) could be observed following addition of purified NAP-1 SSAO protein and benzylamine (an SSAO substrate) to the cell medium. This increase in adhesion molecule expression was less prominent when mutated (enzymatically inactive) NAP-1 SSAO protein was added instead of the native protein.

A number of 1,3,4-oxadiazines are described in the literature (See, for example, Schmitz, e., etal,LiebigsAnn. Chem. (6): 1043 -1046 (1983); Samitov, Y.Y., et al, Zh. Org. Khim. 22(11) :221l-2211 (1986); Potekhin, A.A., et al, Khim. Geterotsikl Soedin. (11): 1461-1468 (1973); Potekhin, A.A., and Zaitsev, B.D., Khim. Geterotsikl. Soedin. 7f3j:301-308 (1971); Ioffe, B.N., andPotekin, A.A., Tetrahedron Lett. (36J:3505-3508 (1967); and Kaneko, Japanese Patent Appl. No. 63256951 (1988)). However, use of these compounds as specific SSAO inhibitors apparently has not been disclosed.

In aqueous solution, 1,3,4-oxadiazines may exist in tautomeric hydrazone form. See, for example, Potekhin, A.A., and Zaitsev, B.D., Khim. Geterotsikl. Soedin. 7(^:301-308 (1971), and Ioffe, B.V., and Potekin, A.A., Tetrahedron Lett. (36)3505-3508 (1967). Takahashi, H, etal, Yakugaku Zasshi 101(12):\\54-\ 156 (1981), report the synthesis of a number of V-alkylaminoephedrines, including N- (isopropylideneamino)-ephedrine (or R,£-(+)-(2-hydroxy-l-methyl-2- phenylethyl)methylhydrazone-2-propanone):

These hydrazone compounds were synthesized to evaluate their effect on the bronchial musculature and were found not to exhibit any significant activity. No mention of a 1,3,4-oxadiazine corresponding to the reported hydrazone appears in this reference.

Grifantini, M., etal,Farmaco, Ed. Sci. 23(3):191-203 (1968), report the synthesis of several alkyl- and acyl-derivatives of N-amino-1-ephedrine and N- amino-d-pseudoephedrine having antidepressant and monoamine oxidase inhibitory properties. Among the compounds disclosed is the hydrazone erythro- (β-hydroxy-α-methylphenethyl)methylhydrazone cyclohexanone, which has the following structure:

The development of specific NAP-1 SSAO inhibitors that modulate NAP-1 activity would be useful for the treatment of chronic inflammatory conditions or diseases such as chronic arthritis, inflammatory bowel diseases, and chronic skin dermatoses, as well as diseases related to carbohydrate metabolism (including diabetes and complications from diabetes), to aberrations in adipocyte differentiation or function and smooth muscle cell function (in particular, athersclerosis), and to various vascular diseases.

Summary of the Invention

The present invention is broadly directed to the use of 1,3,4-oxadiazine compounds of Formula I as inhibitors of the class of copper-containing amine oxidases known as semicarbazide-sensitive amine oxidases (SSAO), including the human SSAO known as Vascular Adhesion Protein-1 (NAP-1). As NAP-1 SSAO inhibitors, compounds of the present invention can function to prevent leukocyte adhesion events mediated through SSAO activity. Compounds of the present invention are therefore useful for treating a number of inflammatory conditions and diseases of connective tissue, skin, and the gastrointestinal, central nervous system, and pulmonary systems, including such conditions as chronic arthritis, inflammatory bowel diseases, and chronic dermatoses. The compounds are also useful for treating diseases related to carbohydrate metabolism (such as diabetes), to aberrations in adipocyte differentiation or function or smooth muscle cell function (such as atherosclerosis and obesity), and to various vascular diseases (such as atheromatous and nonatheromatous ateriosclerosis, ischemic heart disease, and peripheral aterial occlusion). A further aspect of the present invention is to provide a pharmaceutical composition useful for treating disorders responsive to a decrease in SSAO activity, containing an effective amount of a compound of Formula Im^' a mixture with one or more pharmaceutically acceptable carriers or diluents.

A number of compounds useful in the present invention have not been heretofor reported. Thus, the present invention is also directed to novel 1,3,4- oxadiazines of Formula J.

Another embodiment of the present invention is directed to methods for making compounds of Formula J.

Detailed Description of the Embodiments

One aspect of the invention is to use a specific group of 1,3,4- oxadiazine compounds having the general formula J as defined below, for the manufacture of a pharmaceutical preparation for inhibiting a copper-containing amine oxidase.

Another aspect of the invention is to use a specific group of 1,3,4- oxadiazine compounds having the general formula J as defined below, for the manufacture of a pharmaceutical preparation for the treatment of an inflammatory disease or condition, a disease related to carbohydrate metabolism, a disease related to aberrations in adipocyte differentiation or function or smooth muscle cell function, or a vascular disease. A further aspect of the present invention is directed to a method of inhibiting a copper-containing amine oxidase, contacting said amine oxidase with an inhibitory effective amount of a 1,3,4-oxadiazine compound of Formula J:

or a tautomer, isomer, hydrazino alcohol degradation product, or a pharmaceutically acceptable solvate, hydrate, or salt thereof; wherein: R¹ is hydrogen or Ci-C alkyl;

R² is hydrogen, Cι-C₄ alkyl, C₂-C alkenyl, aralkyl, C₂-Cβ alkanoyl, C₃-Cβ alkenoyl, C₇-Cn or aroyl, which is optionally substituted;

R³, R⁴, R⁵, and R⁶, which can be the same or different, are hydrogen, Cι-C alkyl or optionally substituted aryl; or any two of said substituents R³, R⁴, R⁵, and R⁶ are taken together with the carbon atoms to which they are attached to form an optionally substituted carbocyclic or hetercyclic ring; or R² and R³ are taken together with the atoms to which they are attached to form an optionally substituted heterocyclic ring; and R⁷ is hydrogen, Cχ-C₄ alkyl, aryl, substituted aryl, heteroaryl, or aralkyl;

R⁸is Cι-C alkyl, aryl, substituted aryl, heteroaryl, or aralkyl or ⁷ andR⁸ are taken together with the carbon atoms to which they are attached to form an optionally substituted 5-12 membered carbocyclic or heterocyclic ring.

In one embodiment, said contacting occurs in vitro. In another embodiment said contacting occurs in vivo. The present invention is directed to methods of treating or preventing inflammatory diseases or conditions using a 1,3,4-oxadiazine of Formula/:

or a tautomer, isomer, hydrazino alcohol degradation product, isomer, solvate, hydrate, or pharmaceutically acceptable salt thereof; wherein: R¹ is hydrogen or CrC₄ alkyl;

R² is hydrogen, C₁-C₄ alkyl, C₂-C alkenyl, aralkyl, C₂-Cδ alkanoyl, C₃-C6 alkenoyl, or C₇-Cπ aroyl, which is optionally substituted;

R³, R⁴, R⁵, and R⁶, which can be the same or different, are hydrogen, Cι-C₄ alkyl or optionally substituted aryl; or any two of said substituents R³, R⁴, R⁵, and R⁶ are taken together with the carbon atoms to which they are attached to form an optionally substituted carbocyclic or heterocyclic ring; or R² and R³ are taken together with the atoms to which they are attached to form an optionally substituted carbocyclic or heterocyclic ring; and

R⁷ is hydrogen, C C alkyl, aryl, substituted aryl, heteroaryl, or aralkyl; R⁸ is C C₄ alkyl, aryl, substituted aryl, heteroaryl, or aralkyl; or R⁷ and R⁸ are taken together with the carbon atom to which they are attached to form an optionally substituted 5-12 membered carbocyclic or heterocyclic ring.

In one embodiment, the 1,3,4-oxadiazine compounds of Formula /are used to treat or prevent connective tissue inflammatory conditions and diseases. In particular, the compounds can be used to treat such conditions or diseases as rheumatoid arthritis, ankylosing spondylitis, psoriatic arthritis, and osteoarthritis. In another embodiment, the 1,3,4-oxadiazine compounds ofFormula/are used to treat or prevent gastrointestinal inflammatory conditions and diseases, in particular those such as Crohn's disease, ulcerative colitis, and irritable bowel syndrome. In yet another embodiment, the 1,3,4-oxadiazine compounds of Formula/ are used to treat central nervous system inflammatory conditions and diseases, including multiple sclerosis, Alzheimer's disease, and ischaemia-reperfusion injury associated with ischemic stroke.

In another embodiment, the 1,3,4-oxadiazine compounds of Formula/are used to treat or prevent pulmonary inflammatory conditions and diseases. In particular, the compounds can be used to treat or prevent such conditions or diseases as asthma and adult respiratory distress syndrome.

In another embodiment, the 1,3,4-oxadiazine compounds ofFormula/are used to treat or prevent chronic inflammatory skin conditions, especially such inflammatory skin conditions as psoriasis, allegic lesions, lichen planus, and pityriasis rosea.

In yet another embodiment, the 1,3,4-oxadiazine compounds ofFor ula/ are used to treat or prevent diseases related to carbohydrate metabolism and complications thereof, such as diabetes and complications from diabetes, microvascular and macrovascular diseases such as atherosclerosis, vascular retinopathies, and neuropathies such as polyneuropathy, mononeuropathies, and autonomic neuropathy.

In still another embodiment, the 1,3,4-oxadiazine compounds ofFormula/ are used to treat or prevent diseases related to or caused by aberrations in adipocyte differentiation or function, such as atherosclerosis or obesity.

In another embodiment, the 1,3,4-oxadiazine compounds of Formula/are used to treat or prevent diseases related to or caused by aberrations in smooth muscle cell function, such as athersclerosis.

In another embodiment, the 1,3,4-oxadiazine compounds ofFormula/are used to treat or prevent vascular diseases, such as atheromatous and nonatheromatous arteriosclerosis, ischemic heart disease, and Raynaud's Disease and Phenomenon.

Another aspect of the present invention is directed to novel compounds of Formula/, as well as tautomers, or pharmaceutically acceptable solvates, hydrates, or salts thereof, as described above; provided that R³ and R⁴ are not hydrogen or CrC₄ alkyl when R⁷ and/or R⁸ are CrC₄ alkyl or optionally substituted phenyl, or when R⁷ and R⁸ are taken together with the carbon atom to which they are attached for form an unsubstituted C5-G7 cycloalkyl group. The present invention is also directed to pharmaceutical compositions of these novel compounds ofFormula /, as well as to methods of making the novel compounds.

Preferred compounds are those of Formula/ wherein R¹ is hydrogen or C1-C4 alkyl, preferably hydrogen; and R² is hydrogen, C1-C4 alkyl, C₂-C₄alkenyl, C6-C10 ar(Cι-C₄)alkyl, C₂-Cδ alkanoyl, C2-C6 alkenoyl, or benzoyl, any of which may be optionally substituted, and R² is preferably Ci-C₄ alkyl or optionally substituted benzyl. Preferred substituents for the benzyl group of R² are lower alkyl, especially methyl, and nitro, methoxy and halogen, especially chlorine. Especially preferred embodiments of substituted benzyl groups are ?-toluyl, p- mtrobenzyl, -methoxybenzyl, and ^-chlorobenzyl. Suitable values of R¹ are hydrogen, methyl, ethyl, w-propyl, i-propyl, w-butyl, /-butyl, and t-butyl. Suitable values of R² include hydrogen, methyl, ethyl, propyl, isopropyl, benzyl, acetyl, benzoyl, p-toluyl, ?-nitrobenzyl, 7-methoxybenzyl, and -chlorobenzyl.

Preferred compounds ofFormula / also include those compounds wherein R³, R⁴, R⁵ and R⁶ , which can be the same or different, are hydrogen, optionally substituted Cι-C₄ alkyl, or optionally substituted phenyl. Preferred substituents for R³, R⁴, R⁵ and R⁶ are hydrogen and optionally substituted phenyl. Preferred substituted phenyl groups are those substituted with a lower alkyl, especially methyl, or a halogen such as chlorine or fluorine. Especially preferred substituted phenyl groups include o-tolyl, w-tolyl, -tolyl, ^-fluorophenyl and -chlorophenyl. Another group of preferred compounds ofFormula / are those wherein two of said substituents R³, R⁴, R⁵ and R⁶ are taken together to form an optionally substituted 5-12 membered carbocyclic or heterocyclic ring.

The ring formed by two of the substituents R³, R⁴, R⁵ and R⁶ and the carbon atoms to which they are attached is preferably a 5 to 7 membered single ring or a ring to which further rings are condensed {i.e., a ring system). Said 5 to 7 membered ring can be either cis or trans condensed to the oxadiazine ring, and either spiro or fused. The ring can be heterocyclic or carbocyclic and said ring can be saturated or comprise double bonds. The ring or ring system can be unsubstituted or substituted, wherein the substituent can be alkyl, preferably methyl. Preferably, the ring is a saturated carbocyclic ring. Suitable rings include cyclopentane, cyclohexane, 4-methyl-cyclohexane, cycloheptane or a ring included in the adamantane ring system.

In the case where two of the substituents R³, R⁴ R⁵, and R⁶ form a ring, then it is preferred that the two remaining substituents are hydrogen.

Another group of preferred compounds are those of Formula/in whichR² and R³ are taken together to form an optionally substituted heterocyclic ring.

Preferably, the heterocyclic ring formed by the substituents R² and R³ is a 5 to 6 membered nitrogen containing saturated ring. Said ring can be unsubstituted or substituted. According to a preferred embodiment the substituent is alkyl. According to another embodiment, this 5 to 6 membered nitrogen containing ring can be condensed another ring to form a 1,2,3,4- tetrahydroquinoline, 1,2,3,4,-tetrahydroisoquinoline or 2,3-dihydroindole structure. As particularly preferred embodiments can be mentioned piperidine, 1,2,3,4-tetrahydroisoquinoline and 6,7-dimethoxy-l,2,3,4-tetrahydro-isoquinoline.

In the case where R² and R³ together form a heterocyclic ring, then it is preferred that R⁴ is hydrogen.

Preferred compounds also include those ofFormula /in which R⁷ and R⁸, which can be the same or different, are Cι-C alkyl, or Cδ-Cio a^d-G^alkyl. Preferred values of R⁷ and R⁸ include Cι-C₄ alkyl, especially methyl and ethyl. In another group of preferred compounds ofFormula /, R⁷ and R⁸ are taken together with the carbon atoms to which they are attached to form an optionally substituted 5-12 membered carbocyclic or heterocyclic ring. The 5-12 membered ring can be saturated or unsaturated carbocyclic or heterocyclic and said ring can be unsubstituted or substituted. The substituent can be alkyl, aralkyl, or substituted aralkyl. An especially preferred substituent is benzyl. Saturated rings are preferable. A particularly preferable spiro-condensed ring is N- benzylpiperidine.

A preferred subgenus of compounds has Formula la:

or a tautomer, isomer, or a pharmaceutically acceptable solvate, hydrate, or salt thereof, wherein:

R¹² is hydrogen, Cχ-C₄ alkyl or phenyl(Cι-C₃)alkyl;

R¹³ is hydrogen, Cι-C₄ alkyl or phenyl; or R¹⁵ is hydrogen or C C alkyl;

R¹³ and R¹⁵ are taken together with the carbon atoms to which they are attached to form a five to seven membered cycloalkyl ring;

R¹⁴ and R¹⁶ are independently hydrogen or Cι-C alkyl; and

R¹⁷ is C C₄ alkyl, and R¹⁸ is C_x-C₄ alkyl, or R¹⁷ and R¹⁸ are taken together with the carbon atom to which they are attached to form a five or six membered saturated ring optionally including one ring nitrogen (NR¹⁹) where R¹⁹ is hydrogen, CrC alkyl or phenyl(Ci-C₃)alkyl.

Other preferred sub-genuses of the present invention are compounds having either Formula lb or Formula lc: lb lc

or a tautomer, isomer, or a pharmaceutically acceptable solvate, hydrate, or salt thereof, wherein:

R 22 is hydrogen, Cι-C₄ alkyl or benzyl, preferably methyl or benzyl;

R 23 is hydrogen or C₁-C₄ alkyl, preferably hydrogen or methyl;

R 24 is hydrogen or C₁-C alkyl;

R 25 is hydrogen, Ci-C₄ alkyl or phenyl, preferably hydrogen or phenyl;

R 26 is hydrogen or C₁-C alkyl;

R R 2"7 is Cι-C₄ alkyl;

R 28 is Ci-C₄ alkyl; and X is a covalent bond, -CH₂- or -NR¹⁹-, where R¹⁹ is hydrogen, C1-C4 alkyl or benzyl.

Examples of compounds of, and useful in, the present invention include: 9-benzyl-2-methyl-5-oxa-l,2,9-triazaspiro[5.5]undecane;

9-benzyl-2-methyl-4-phenyl-5-oxa-l,2,9-triazaspiro[5.5]-undecane; (3S,4R)-9-benzyl-2,3-dimethyl-4-phenyl-5-oxa-l,2,9-triazaspiro[5.5]undecane; (3R,4S)-2,3 -dimethyl-4-phenyl-5-oxa- 1 ,2-diazaspiro[5.5]undecane; (4aR*,8aS*)-4-methyl-2,2-pentamethylene-3,4,4a,5,6,7,8,8a-octahydro-2H-l,3,4- benzoxadiazine;

(4aR*,8aR*)-2,2,4-trimethyl-3,4,4a,5,6,7,8,8a-octahydro-2H-l,3,4- benzoxadiazine;

(4aR*,8aR*)-4-benzyl-2-ethyl-2-methyl-3,4,4a,5,6,7,8,8a-octahydro-2H-l,3,4- benzoxadiazine; and 2,2-dimethyl-l,2,4a,5-tetrahydro-4H,10H-l,3,4-oxadiazino[4,5-i]isoquinoline; as well as pharmaceutically acceptable salts thereof, including, for example, hydrochloride or dihydrochloride salts.

The term "alkyl" as employed herein by itself or as part of another group refers to both straight and branched chain radicals of up to 12 carbons, such as methyl, ethyl, propyl, isopropyl, butyl, t-butyl, isobutyl, pentyl, hexyl, isohexyl, heptyl, 4,4-dimethylpentyl, octyl, 2,2,4-trimethylpentyl, nonyl, decyl, undecyl, dodecyl. For example, Cι-C alkyl is a straight or branched alkyl and thus can include methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl and isobutyl.

The term "alkenyl" is used herein to mean a straight or branched chain radical of 2-20 carbon atoms, unless the chain length is limited thereto, including, but not limited to, ethenyl, 1-propenyl, 2-propenyl, 2-methyl-l-propenyl, 1- butenyl, 2-butenyl, and the like. Preferably, the alkenyl chain is 2 to 10 carbon atoms in length, more preferably, 2 to 8 carbon atoms in length most preferably from 2 to 4 carbon atoms in length.

The term "aryl" as employed herein by itself or as part of another group refers to monocyclic or bicyclic aromatic groups containing from 6 to 12 carbons in the ring portion, preferably 6-10 carbons in the ring portion, such as phenyl, naphthyl or tetrahydronaphthyl.

The term "aralkyl" as employed herein should be interpreted as any aryl attached to the alkyl, which is a chain of 1 to 6 carbon atoms and which in turn can be straight or branched. Preferably, the chain contains 1 to 3 carbon atoms. A preferred aryl group is phenyl, which can be substituted or unsubstituted. Preferable substituents are lower alkyl (i.e., Ci-C alkyl), especially methyl, or a halogen. As particular preferred embodiments can be mentioned benzyl, p- methylbenzyl, >-chlorobenzyl, 2-phenylethyl and 3-phenylpropyl.

The term "alkanoyl" as employed herein refers to a carbonyl moiety to which is attached any of the above alkyl groups. For example, the term "C₂-Cβ alkanoyl" includes, but is not limited to, ethanoyl, propanoyl, butanoyl, 2-methyl- propanoyl, pentanoyl, hexanoyl. The term "alkenoyl" is used herein to mean a carbonyl moiety to which is attached any of the above alkenyl groups. For example, the term"C₂-C6 alkenoyl" refers to, but is not limited to, ethenoyl, 1-propenoyl, 2-propenoyl, 2-methyl-l- propenoyl, 1-butenoyl, 2-butenoyl, and the like. Preferably, the alkenyl chain is 2 to 10 carbon atoms in length, and more preferably, 2 to 6 carbon atoms in length. The term "carbocyclic ring" as employed herein by itself or as part of another group refers to a monocyclic or bicyclic aromatic ring or ring system containing from 6 to 12 carbons in the ring portion, as defined above, or to any 3- to 9-membered mono- or 7- to 10-membered bicyclic carbon ring system, any ring of which may be saturated or unsaturated. Typical examples include phenyl, naphthyl, and cyclohexyl.

The term "heterocyclic ring" as used herein represents a stable 5- to 7- membered mono- or bicyclic or stable 7- to 12-membered bicyclic heterocyclic ring system any ring of which may be saturated or unsaturated, and which consists of carbon atoms and from one to three heteroatoms selected from the group consisting of N, O and S, and wherein the nitrogen and sulfur heteroatoms may optionally be oxidized, and the nitrogen heteroatom may optionally be quaternized, and including any bicyclic group in which any of the above-defined heterocyclic rings is fused to a benzene ring. Especially useful are rings containing one oxygen or sulfur, one to three nitrogen atoms, or one oxygen or sulfur combined with one or two nitrogen atoms. The heterocyclic ring may be attached at any heteroatom or carbon atom which results in the creation of a stable structure. Examples of such heterocyclic groups include piperidinyl, piperazinyl, N-benzylpiperidine, 2-oxopiperazinyl, 2-oxopiperidinyl, 2-oxopyrrolodinyl, 2- oxoazepinyl, azepinyl, pyrrolyl, 4-piperidonyl, pyrrolidinyl, pyrazolyl, pyrazolidinyl, imidazolyl, imidazolinyl, imidazolidinyl, pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, oxazolyl, oxazolidinyl, isoxazolyl, isoxazolidinyl, morpholinyl, thiazolyl, thiazolidinyl, isothiazolyl, quinuclidinyl, isothiazolidinyl, indolyl, quinolinyl, isoquinolinyl, chromanyl, benzimidazolyl, thiadiazoyl, benzopyranyl, benzothiazolyl, benzo[b]thiophenyl, benzo[2,3-c] 1,2,5-oxadiazolyl, benzoxazolyl, furyl, tetrahydrofuryl, tetrahydropyranyl, thienyl, benzothienyl, thiamorpholinyl, thiamorpholinyl sulfoxide, thiamorpholinyl sulfone, and oxadiazolyl. Morpholino is the same as morpholinyl.

The term "heteroaryl" as employed herein refers to groups having 5 to 14 ring atoms; 6, 10 or 14 B electrons shared in a cyclic array; and containing carbon atoms and 1, 2 or 3 oxygen, nitrogen or sulfur heteroatoms (where examples of heteroaryl groups are: thienyl, benzo[b]thienyl, naphtho[2,3-b]thienyl, thianthrenyl, furyl, pyranyl, isobenzofuranyl, benzoxazolyl, chromenyl, xanthenyl, phenoxathiinyl, 2H-pyrrolyl, pyrrolyl, imidazolyl, pyrazolyl, pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, indolizinyl, isoindolyl, 3H-indolyl, indolyl, indazolyl, purinyl, 4H-quinolizinyl, isoquinolyl, quinolyl, phthalazinyl, naphthyridinyl, quinazolinyl, cinnolinyl, pteridinyl, 4αH-carbazolyl, carbazolyl, β-carbolinyl, phenanthridinyl, acridinyl, perimidinyl, phenanthrolinyl, phenazinyl, isothiazolyl, phenothiazinyl, isoxazolyl, furazanyl and phenoxazinyl groups).

The term "halogen" or "halo" as employed herein by itself or as part of another group refers to chlorine, bromine, fluorine or iodine, with chlorine being preferred.

The term "substituted" unless otherwise provided for herein, refers to one or more groups independently selected from the group consisting of halo, halo (Cj.

6)alkyl, ar(Cχ-6)alkyl, aryl, nitro, Cι-6 alkoxy, and Cχ.6 alkyl as long as the resulting compound is stable. Preferred optional substituents include: halo, ar(Cι-6)alkyl, aryl, and Cι-6 alkyl.

The term "cycloalkyl" as employed herein by itself or as part of another group refers to cycloalkyl groups containing 3 to 9 carbon atoms. Typical examples are cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl and cyclononyl.

The term "hydroxyalkyl" as employed herein refers to any of the above alkyl groups substituted by one or more hydroxyl moieties.

The term "carboxyalkyl" as employed herein refers to any of the above alkyl groups substituted by one or more carboxylic acid moieties. The term "haloalkyl" as employed herein refers to any of the above alkyl groups substituted by one or more chlorine, bromine, fluorine or iodine with fluorine and chlorine being preferred, such as chloromethyl, iodomethyl, trifluoromethyl, 2,2,2-trifluoroethyl, and 2-chloroethyl. The term "haloalkoxy" as used herein refers to any of the above haloalkyl groups bonded to an oxygen atom, such as trifluromethoxy, trichloromethoxy, and the like.

The term "alkoxy" is used herein to mean a straight or branched chain radical of 1 to 20 carbon atoms, unless the chain length is limited thereto, bonded to an oxygen atom, including, but not limited to, methoxy, ethoxy, «-propoxy, isopropoxy, and the like. Preferably the alkoxy chain is 1 to 10 carbon atoms in length, more preferably 1 to 8 carbon atoms in length.

The compounds of the invention will in general exist in equilibrium with their other tautomeric forms. For example, compounds of Formula /may exist in solution as mixtures of ring (Id) and chain (Ie) tautomers:

Id Ie wherein R^R⁸ are as defined above. It is to be understood that all tautomeric forms of the compounds ofFormula/, as well as all possible mixtures thereof, are included within the scope of the present invention. There is evidence that it is the hydrazino alcohol form of the disclosed compounds that binds to NAP-1 and inhibits its SSAO activity. Thus, it is to be further understood that such hydrazino alcohol degradation products of the disclosed compounds are to be included within the scope of the compounds of Formula /when they are used to inhibit NAP-1 SSAO activity and to treat the various NAP-1 mediated diseases and conditions described herein.

Some of the compounds disclosed herein may contain one or more asymmetric centers and may thus give rise to enantiomers, diastereomers, and other stereoisomeric forms. The present invention is also meant to encompass racemic mixtures, resolved forms and mixtures thereof, as well as the individual enantiomers that may be separated according to methods that are well know to those of ordinary skill in the art. When the compounds described herein contain olefinic double bonds or other centers of geometric asymmetry, and unless specified otherwise, it is intended to include both E and Z geometric isomers.

As used herein, the term "stereoisomers" is a general term for all isomers of individual molecules that differ only in the orientation of their atoms in space. It includes enantiomers and isomers of compounds with more than one chiral center that are not mirror images of one another (diastereomers).

The term "asymmetric center" or "chiral center" refers to a carbon atom to which four different groups are attached.

The term "enantiomer" or "enantiomeric" refers to a molecule that is nonsuperimposeable on its mirror image and hence optically active wherein the enantiomer rotates the plane of polarized light in one direction and its mirror image rotates the plane of polarized light in the opposite direction.

The term "racemic" refers to a mixture of equal parts of enantiomers and which is optically inactive. The term "resolution" refers to the separation or concentration or depletion of one of the two enantiomeric forms of a molecule. The phrase "enantiomeric excess" refers to a mixture wherein one enantiomer is present is a greater concentration than its mirror image molecule.

When any variable occurs more than one time in any constituent or in Formula /, its definition on each occurrence is independent of its definition at every other occurrence. Also, combinations of substituents and/or variables are permissible only if such combinations result in stable compounds.

Another aspect of the present invention is directed to methods for preparing compounds ofFormula /. The compounds of the present invention can be prepared by one of the following routes. Synthesis of the compounds of Formula / (compounds ) starts from hydrazino alcohols II and uses ketones IV or ketone equivalents, e.g. acetals V (R⁹ is preferably a methyl or ethyl group), as condensing agents.

Condensations are performed at 20-120 °C, with or without acidic or basic catalysts, or adsorbents of water. Illustrative examples of "acidic catalysts" are hydrochloric, /?-toluenesulfonic, acetic, and tartaric and oxalic acids. An "acidic catalyst" may also include any strongly acid resin ion-exchange resin suitable for non-aqueous catalysis, such as Amberlist^® 15. An illustrative example of "a basic catalyst" is triethylamine. The term "water adsorbent" includes dried magnesium sulfate, silica and molecular sieve 4A.

An alternative procedure for the synthesis of compounds I uses amino alcohols HI and oxaziridines VI (Schmitz, E., etal, LiebigsAnn. Chem. :1043- 1046 (1983)).

Hydrazino alcohols TL are known from the literature or can be prepared following the literature processes by starting from amino alcohol precursors HI (Taguchi, T. et al, J. Org. Chem. 29: 1097-1103 (1964); Takahashi, H, et al, Chem. Pharm. Bull. 39:836-842 (1991); Shen, J.K., etal, J. Chem. Soc, Perkin Trans. 7:2087-2097 (1993); Rosling, A, etal, Heterocycles 45:95-106 (1997); Rosling, A., et al, J. Chem. Res.(S):492 (1998); J Chem. Res. (M):2231 -2250 (1998)). In the cases R³ ≠ R⁴ and R⁵ ≠ R⁶, hydrazino alcohols π are used as single diastereomers. The synthesis of the enantiomers of compounds I starts from enantiomerically pure hydrazino alcohols π, which are known from the literature or can be prepared following the literature processes (Trepanier, D.L., et al, J. Org. Chem. 29:668-672 (1964)). Condensations occur without racemization. Enantiomerically pure products I can also be prepared by standard enantiomer separation techniques from the racemates of I.

For compounds I in which R⁷ ≠ R⁸ and R³ ≠ R⁴ or R⁵ ≠ R⁶, geometric isomerism is possible. Diastereomers formed in condensations can be separated, if necessary, by standard organic separation methods.

The compounds of this invention are useful in the form of acid addition salts. The expression "pharmaceutically acceptable acid addition salt" is intended to apply to any non-toxic organic and inorganic acid addition salts of the base compounds ofFormula /. Illustrative inorganic acids which form suitable salts include hydrochloric, hydrobromic, sulfuric and phosphoric acids. Illustrative organic acids which form suitable salts include acetic, lactic, malonic, succinic, glutaric, fumaric, malic, tartaric, citric, ascorbic, maleic, benzoic, phenylacetic, cinnamic and salicylic acids

Id Ie

Compounds I exist in solution as mixtures of ring (Id) and chain (Ie) tautomers. The equilibria exhibit a strong dependence on the substituents and the solvents used (Dorman, L.C., J. Org. Chem. 29:255-260 (1967); Potekhin, A. A. and Zaitsev, B.D., Chem. Heterocyclic Compounds 7:277-301 (1971); Potekhin, A. A. andBogankova, E.A., Chem. Heterocyclic Compounds 9:1321-1461 (1973); Valters, R.E., et al, Adv. Heterocyclic Chem. 66:1-11 (1996)). On the other hand, crystals of hydrochloride salts of I exist individually in ring form, as proved by solid-state NMR measurements. The present invention provides a method of treating VAP-1 mediated conditions by selectively inhibiting VAP-1 SSAO activity, which method comprises administering to an animal in need thereof a therapeutically effective amount of a compound selected from the class of compounds depicted by Formula /, wherein one or more compounds of Formula /is administered in association with one or more non-toxic, pharmaceutically acceptable carriers and/or diluents and/or adjuvants and if desired other active ingredients.

The compounds of the present invention can be used to treat inflammatory conditions and diseases including but not limited to connective tissue inflammatory conditions and diseases such as ankylosing spondylitis, Reiter's syndrome, psoriatic arthritis, osteoarthritis or degenerative joint disease, rheumatoid arthritis, Sjogren's syndrome, Behcet's syndrome, relapsing polychondritis, systemic lupus erythematosus, discoid lupus erythematosus, systemic sclerosis, eosinophilic fasciitis, polymyositis and dermatomyositis, polymyalgia rheumatica, vasculitis, temporal arteritis, polyarteritis nodosa, Wegener's granulomatosis, mixed connective tissue disease, and juvenile rheumatoid arthritis; gastrointestinal inflammatory conditions and diseases such as Crohn's disease, ulcerative colitis, irritable bowel syndrome (spastic colon), fibrotic conditions of the liver, inflammation of the oral mucosa (stomatitis), and recurrent aphtous stomatitis; central nervous system inflammatory conditions and diseases such as multiple sclerosis, Alzheimer's disease, and ischaemia-reperfusion injury associated with ischemic stroke; pulmonary inflammatory conditions and diseases such as asthma, chronic obstructive pulmonary disease, and adult respiratory distress syndrome; and skin inflammatory conditions and diseases such as contact dermatitis, atopic dermatitis, psoriasis, pityriasis rosea, lichen planus, and pityriasis rubra pilaris. Moreover, the compounds of the invention can be used to treat diseases related to carbohydrate metabolism and complications thereof, such as diabetes and complications of diabetes including, but not limited to microvascular and macrovascular disease such as atherosclerosis, vascular retinopathies, retinopathy, nephropathy and nephrotic syndrome, neuropathies such as polyneuropathy, mononeuropathies, and autonomic neuropathy, and foot ulcers and joint problems, as well as increased risk of infection; diseases related to or caused by aberrations in adipocyte differentiation or function such as atherosclerosis and obesity; and vascular diseases such as atheromatous and nonatheromatous ateriosclerosis, ischemic heart disease including myocardial infarction, peripheral aterial occlusion, thromboangiitis obliterans (Buerger's disease), and Raynaud's disease and phenomenon.

In particular, the present compounds can be used to treat atherosclerosis. It is known that VAP-1 is expressed on adipocytes, smooth muscle cells, endothelial cells and is related to inflammation. Atherosclerotic plaque consists of accumulated intracellular and extracellular lipids, smooth muscle cells, connective tissue, and glycosaminoglycans. The earliest detectable lesion of atherosclerosis is the fatty streak (consisting of lipid-laden foam cells, which are macrophages that have migrated as monocytes from the circulation into the subendothelial layer of the intima), which later evolves into the fibrous plaque (consisting of intimal smooth muscle cells surrounded by connective tissue and intracellular and extracellular lipids). The term "treat inflammation" is intended to include the administration of compounds of the present invention to a subject for purposes, which can include prophylaxis, amelioration, prevention or cure of an inflammatory condition or disease. Such treatment need not necessarily completely ameliorate the inflammatory condition or disease. Further, such treatment can be used in conunction with other traditional treatments for reducing the inflammatory condition known to those of skill in the art.

The compounds of the present invention may be administered in an effective amount within the dosage range of about 0.1 μg kg to about 300 mg/kg, preferably between 1.0 μg/kg to 10 mg/kg body weight. Compounds of the present invention may be administered in a single daily dose, or the total daily dosage may be administered in divided doses of two, three or four times daily.

The pharmaceutical compositions of the present invention can be administered to any animal that can experience the beneficial effects of the compounds of the invention. Foremost among such animals are humans, although the invention is not intended to be so limited.

The pharmaceutical compositions of the present invention can be administered by any means that achieve their intended purpose. For example, administration can be by parenteral, subcutaneous, intravenous, intramuscular, intraperitoneal, or intradermal injections, or by transdermal, buccal, or ocular routes. Alternatively, or concurrently, administration can be by the oral route. Particularly preferred is oral administration. The dosage administered will be dependent upon the age, health, and weight of the recipient, kind of concurrent treatment, if any, frequency of treatment, and the nature of the effect desired. In addition to the pharmacologically active compounds, the pharmaceutical preparations of the compounds can contain suitable pharmaceutically acceptable carriers comprising excipients and auxiliaries that facilitate processing of the active compounds into preparations that can be used pharmaceutically. The pharmaceutical preparations of the present invention are manufactured in a manner that is, itself, known, for example, by means of conventional mixing, granulating, dragee-making, dissolving, or lyophilizing processes. Thus, pharmaceutical preparations for oral use can be obtained by combining the active compounds with solid excipients, optionally grinding the resulting mixture and processing the mixture of granules, after adding suitable auxiliaries, if desired or necessary, to obtain tablets or dragee cores.

Suitable excipients are, in particular, fillers such as saccharides, for example, lactose or sucrose, mannitol or sorbitol, cellulose preparations and/or calcium phosphates, for example, tricalcium phosphate or calcium hydrogen phosphate, as well as binders, such as starch paste, using, for example, maize starch, wheat starch, rice starch, potato starch, gelatin, tragacanth, methyl cellulose, hydroxypropylmethylcellulose, sodium carboxymethylcellulose, and/or polyvinyl pyrrolidone. If desired, disintegrating agents can be added, such as the above-mentioned starches and also carboxymethyl-starch, cross-linked polyvinyl pyrrolidone, agar, or alginic acid or a salt thereof, such as sodium alginate. Auxiliaries are, above all, flow-regulating agents and lubricants, for example silica, talc, stearic acid or salts thereof, such as magnesium stearate or calcium stearate, and/or polyethylene glycol. Dragee cores are provided with suitable coatings, that, if desired, are resistant to gastric juices. For this purpose, concentrated saccharide solutions can be used, which may optionally contain gum arabic, talc, polyvinyl pyrrolidone, polyethylene glycol, and/or titanium dioxide, lacquer solutions and suitable organic solvents or solvent mixtures. In order to produce coatings resistant to gastric juices, solutions of suitable cellulose preparations, such as acetylcellulose phthalate or hydroxypropylmethylcellulose phthalate, are used. Dye stuffs or pigments can be added to the tablets or dragee coatings, for example, for identification or in order to characterize combinations of active compound doses.

Other pharmaceutical preparations that can be used orally include push-fit capsules made of gelatin, as well as soft, sealed capsules made of gelatin and a plasticizer such as glycerol or sorbitol. The push-fit capsules can contain the active compounds in the form of granules that may be mixed with fillers such as lactose, binders such as starches, and/or lubricants such as talc or magnesium stearate and, optionally, stabilizers. In soft capsules, the active compounds are preferably dissolved or suspended in suitable liquids such as fatty oils or liquid paraffin. In addition, stabilizers may be added.

Suitable formulations for parenteral administration include aqueous solutions of the active compounds in water-soluble form, for example water- soluble salts and alkaline solutions. Especially preferred alkaline salts are ammonium salts prepared, for example, with Tris, choline hydroxide, bis-Tris propane, N-methylglucamine, or arginine. In addition, suspensions of the active compounds as appropriate oily injection suspensions can be administered. Suitable lipophilic solvents or vehicles include fatty oils, for example, sesame oil, or synthetic fatty acid esters, for example, ethyl oleate or triglycerides or polyethylene glycol-400 (the compounds are soluble in PEG-400). Aqueous injection suspensions can contain substances that increase the viscosity of the suspension, for example sodium carboxymethyl cellulose, sorbitol, and/or dextran. Optionally, the suspension may also contain stabilizers.

The following examples are illustrative, but not limiting, of the method and compositions of the present invention. Other suitable modifications and adaptations of the variety of conditions and parameters normally encountered and obvious to those skilled in the art are within the spirit and scope of the invention.

Example 1 9-Benzyl-2-methyl-5-oxa-l,2, 9-triazaspiro[5. SJundecane dihydrochloride

The title compound was synthesized using each of the following three synthetic methods.

Method la: To a solution of 2-(Nⁱ-methylhydrazino)ethanol (0.30 g, 3.3 mmol) in dry toluene (10 ml), l-benzylpiperidin-4-one (0.63 g, 3.3 mmol) was added and the reaction mixture was left to stand at room temperature for 24 hours. The toluene solution was decanted from the separated droplets of water and evaporated to dryness. Evaporation was repeated after the addition of dry toluene (10 ml). The pale-yellow oily product was dissolved in ethanol (2 ml) and was converted to the crystalline dihydrochloride salt by using ethanol containing 22% hydrogen chloride (1 ml) and diethyl ether. The crystals were filtered off and recrystallized from ethanol/diethyl ether. ¹³C-NMR (500 MHz, solid state): δ 26.61, (broad), 33.81, 44.1, 52.2, 57.93, 83.44 (C-2), 128.42, 130.0, 133.04. Method lb: To a solution of 2-(V^;-methylhydrazino)ethanol (0.30 g, 3.3 mmol) in dry toluene (10 ml), l-benzylpiperidin-4-one (0.63 g, 3.3 mmol) was added. The reaction mixture was refluxed for 5 hours and then evaporated to dryness. Evaporation was repeated after the addition of dry toluene (10 ml). The pale-yellow oily product was dissolved in ethanol (2 ml) and was converted to the crystalline dihydrochloride salt by using ethanol containing 22% hydrogen chloride (1 ml) and diethyl ether. The crystals were filtered off and recrystallized from ethanol/diethyl ether. ¹³C-NMR: see Method la.

Method lc: To a solution of 2-(N^" -methylhydrazino)ethanol (0.30 g, 3.3 mmol) in dry toluene (10 ml), l-benzylpiperidin-4-one (0.63 g, 3.3 mmol) was added. The reaction mixture was refluxed for 5 hours in a Dean-Stark apparatus and then evaporated to dryness. The oily residue was dissolved in ethanol (2 ml) and was converted to the crystalline dihydrochloride salt by using ethanol containing 22% hydrogen chloride (1 ml) and diethyl ether. The crystals were filtered off and recrystallized from ethanol/diethyl ether. ¹³C-NMR: see

Method la.

Example 2 9-Benzyl-2-methyl-4-phenyl-5-oxa-l,2,9-triazaspiro[5.5]undecane dihydrochloride

The title compound was synthesized using each of the following two synthetic methods.

Method 2a: To a solution of 2-(-V^;-methylhydrazino)-l-phenylethanol

(0.50 g, 3 mmol) in dry toluene (25 ml), l-benzylpiperidin-4-one (0.57 g, 3 mmol) and a catalytic amount (1 drop) of glacial acetic acid were added. The reaction mixture was left to stand at room temperature for 24 hours and then evaporated to dryness. Evaporation was repeated after the addition of dry toluene (10 ml). The pale-yellow oily product was dissolved in ethanol (2 ml) and was converted to the crystalline dihydrochloride salt by using ethanol containing 22% hydrogen chloride (1 ml) and diethyl ether. The crystals were filtered off and recrystallized from ethanol diethyl ether. ¹³C-NMR (500 MHz, solid state): δ 26.61, (broad), 33.81, 44.1, 52.2, 57.93, 83.44 (C-2), 128.42, 130.0, 133.04.

Method 2b: To a solution of 2-(N^/-methylhydrazino)-l-phenylethanol (0.50 g, 3 mmol) in dry toluene (25 ml), l-benzylpiperidin-4-one (0.57 g, 3 mmol) and a catalytic amount (1 drop) of triethylamine were added. The reaction mixture was left to stand at room temperature for 24 hours and then evaporated to dryness. Evaporation was repeated after the addition of dry toluene (10 ml). The pale-yellow oily product was dissolved in ethanol (2 ml) and was converted to the crystalline dihydrochloride salt by using ethanol containing 22% hydrogen chloride (1 ml) and diethyl ether. The crystals were filtered off and recrystallized from ethanol/diethyl ether. ¹³C-NMR: see Method 2a.

Example 3

(3S,4R)-9-Benzyl-2,3-dimethyl-4-phenyl-5-oxa-l,2,9- triazaspiro[5.5]undecane dihydrochloride

The title compound was synthesized using each of the following two synthetic methods.

Method 3a: To a solution of (lR,2S)-iV-aminoeρhedrine (0.30 g, 1.7 mmol) in dry benzene (30 ml), l-benzylpiperidin-4-one (0.31 g, 1.6 mmol) was added. The reaction mixture was left to stand at room temperature for 6 hours, and then evaporated to dryness. The residue was dissolved in 5 ml ethanol containing 22% hydrogen chloride after a few minutes the solution was evaporated to dryness, and the residue was crystallized from an ethanol/diethyl ether mixture. ¹³C-NMR (500 MHz, solid state): δ 4.97, 28.42, 41.01, 46.9, 49.5, 59.57, 71.69, 83.87 (C-2), 129.67.

Method 3b: To a solution of (lR,2S)-N^~-aminoephedrine (0.30 g, 1.7 mmol) in dry benzene (30 ml), l-benzylpiperidin-4-one (0.31 g, 1.6 mmol) was added, followed by a few drops of ethanol containing 22% hydrogen chloride. The reaction mixture was stirred at room temperature for 6 hours, and then evaporated to dryness. The residue was dissolved in 5 ml ethanol containing 22% hydrogen chloride, after a few minutes the solution was evaporated to dryness and the residue was crystallized from an ethanol/diethyl ether mixture. ¹³C-NMR: see Method 3 a.

Example 4 (3T0,4S)-2,3-Dimethyl-4-phenyl-5-oxa-l,2-diazaspiro[5.5]undecane hydrochloride

The title compound was synthesized using each of the following four synthetic methods.

Method 4a: To a solution of (lS,2R)-iV-aminoephedrine (0.30 g, 1.7 mmol) in dry benzene (40 ml), cyclohexanone (0.83 g, 8.5 mmol) was added. The reaction mixture was left to stand at room temperature for 6 hours, and then evaporated to dryness. The residue was dissolved in 5 ml ethanol containing 22% hydrogen chloride, after a few minutes the solution was evaporated to dryness and the semisolid residue was crystallized from an ethanol/diethyl ether mixture. ¹³C- NMR (500 MHz, solid state): δ 4.28, 24.0 (broad), 38.25, 45.05, 58.98, 70.53, 87.5 (C-2), 129.67.

Method 4b: To a solution of (lS,2R)-7V-aminoephedrine (0.30 g, 1.7 mmol) in dry benzene (40 ml) cyclohexanone (0.83 g, 8.5 mmol) and a catalytic amount (some crystals) of 7-toluenesulfomc acid were added. The reaction mixture was left to stand at room temperature for 6 hours, and then evaporated to dryness. The residue was dissolved in 5 ml ethanol containing 22% hydrogen chloride, after a few minutes the solution was evaporated to dryness and the semisolid residue was crystallized from an ethanol/diethyl ether mixture. ¹³C- NMR: see Method 4a.

Method 4c: To a solution of (lS,2R)-iV-aminoephedrine (0.30 g, 1.7 mmol) in dry benzene (40 ml), cyclohexanone (0.83 g, 8.5 mmol) and Amberlist^® 15 ion-exchange resin (0.1 g) were added. The reaction mixture was stirred at room temperature for 5 hours, the ion-exchange resin was then filtered off and the filtrate was evaporated to dryness. The residue was dissolved in 5 ml ethanol containing 22% hydrogen chloride, after a few minutes the solution was evaporated to dryness and the semisolid residue was crystallized from an ethanol/diethyl ether mixture. ¹³C-NMR: see Method 4a.

Method 4d: To a solution of (lS,2R)-N-aminoephedrine (0.30 g, 1.7 mmol) in dry methylene chloride (25 ml), cyclohexanone (0.83 g, 8.5 mmol) and anhydrous magnesium sulfate (5 g) were added. The reaction mixture was stirred at room temperature for 10 hours, the magnesium sulfate was then filtered off and the filtrate was evaporated to dryness. The residue was dissolved in 5 ml ethanol containing 22% hydrogen chloride, after a few minutes the solution was evaporated to dryness and the semisolid residue was crystallized from an ethanol/diethyl ether mixture. ¹³C-NMR: see Method 4a.

Example 5

(4άR*, 8aS *)-4-Methyl-2,2-pentamethylene-3, 4, 4a, 5, 6, 7, 8, 8a-octahydro-2R-

1,3,4-benzoxadiazine hydrochloride

The title compound was synthesized using each of the following three synthetic methods.

Method 5a: To a solution of l-oxa-2-azaspiro[2.5]octane (0.60 g, 5.3 mmol) in diethyl ether (20 ml), a solution of ezs-2-(methylamino)cyclohexanol (0.68 g, 5.3 mmol) in diethyl ether (5 ml) was added. The reaction mixture was stirred at room temperature for 30 minutes and then evaporated to dryness. The residue was dissolved in 5 ml ethanol containing 22% hydrogen chloride, after a few minutes the solution was evaporated to dryness and the semisolid residue was crystallized from an ethanol/diethyl ether mixture. ¹³C-NMR (500 MHz, solid state): δ 24.01 (broad), 42.6, 60.1, 65.9, 86.86 (C-2).

Method 5b: To a solution of cis-2-(JV^/-methylhydrazino)cyclohexanol (0.43 g, 3 mmol) in dry benzene (40 ml), cyclohexanone (1.47 g, 15 mmol) and molecular sieve 4A (8 g) were added. The reaction mixture was stirred at room temperature for 10 hours, the molecular sieve was then filtered off and the filtrate was evaporated to dryness. The residue was dissolved in 5 ml ethanol containing 22% hydrogen chloride, after a few minutes the solution was evaporated to dryness and the semisolid residue was crystallized from an ethanol/diethyl ether mixture. ¹³C-NMR: see Method 5a.

Method 5c: To a solution of cz^'5-2-(N^/-methylhydrazino)cyclohexanol (0.43 g, 3 mmol) in dry toluene (40 ml), cyclohexanone (1.47 g, 15 mmol) and silica gel (0.035-0.07 mm, 2 g) were added. The reaction mixture was stirred at room temperature for 8 hours, the silica gel was then filtered off and the filtrate was evaporated to dryness. The residue was dissolved in 5 ml ethanol containing 22%o hydrogen chloride, after a few minutes the solution was evaporated to dryness and the semisolid residue was crystallized from an ethanol/diethyl ether mixture. ¹³C-NMR: see Method 5a.

Example 6

(4aR*,8άR*)-2,2,4-Trimethyl-3,4,4a,5,6,7,8,8a- ctahydro-2K-l,3,4- benzoxadiazine hydrochloride

The title compound was synthesized using each of the following two synthetic methods. Method 6a: A solution of trαw5-2-(-V^/-methylhydrazino)cyclohexanol

(0.35 g, 2.4 mmol) in dry acetone (40 ml) was left to stand at room temperature for 6 hours. The solution was then evaporated to dryness and 5 ml ethanol containing 22% hydrogen chloride was added. After a few minutes, the solution was evaporated to dryness and the residue was recrystallized from an ethanol diethyl ether mixture. ¹³C-NMR (500 MHz, solid state): δ 21.2, 25.2, 27.6, 31.5, 42.3, 68.5, 74.3, 88.46 (C-2).

Method 6b: A solution of a mixture of trans-2-(N^l- methylhydrazino)cyclohexanol (0.35 g, 2.4 mmol) in dry acetone (40 ml) and a catalytic amount of ethanol containing 22% hydrogen chloride (1 drop) was left to stand at room temperature for 72 hours. The solution was then evaporated to dryness and the residue was recrystallized from a methanol/diethyl ether mixture. ¹³C-NMR: see Method 6a.

Example 7 (4aR*,8aR*H-Benzyl-2-ethyl-2methyl-3,4,4a,5,6,7,8,8a- ctahydro-2R-

1,3,4-benzoxadiazine hydrochloride

Method 7a: To a solution of frαrø-2-(iV¹-benzylhydrazino)cyclohexanol (0.66 g, 3 mmol) in 2-butanone (25 ml), a catalytic amount of oxalic acid was added. The reaction mixture was left to stand at room temperature for 24 hours and then evaporated to dryness. The pale-yellow oily product was dissolved in methanol (2 ml) and was converted to the crystalline dihydrochloride salt by using ethanol containing 22% hydrogen chloride (1 ml) and diethyl ether. The crystals were filtered off and recrystallized from methanol/diethyl ether. ¹³C-NMR (500 MHz, solid state): δ 7.98, 16.9, 23.4, 26.2, 30.1, 59.9, 67.2, 90.49 (C-2), 128.1, 139.3.

Example 8

2,2-Dimethyl-l,2,4a,5-tetrahydro-4B.,10R-l,3,4-oxadiazino[4,5- bβsoquinoline hydrochloride

The title compound was synthesized using each of the following three synthetic methods.

Method 8a: To a solution of 2-amino-l,2,3,4-tetrahydroisoquinoline 3- methanol (0.53 g, 3 mmol) in 2,2-dimethoxypropane (25 ml), a catalytic amount of p-toluenesulfonic acid was added. The reaction mixture was left to stand at room temperature for 24 hours and then evaporated to dryness. The pale-yellow oily product was dissolved in methanol (2 ml) and was converted to the crystalline dihydrochloride salt by using ethanol containing 22% hydrogen chloride (1 ml) and diethyl ether. The crystals were filtered off and recrystallized from methanol/diethyl ether. ¹³C-NMR (500 MHz, solid state): δ 15.1, 20.7, 27.8, 56.14, 63.0, 89.90 (C-2), 127.4, 130.1. Method 8b: To a solution of 2-ammo-l,2,3,4-tetrahydroisoquinoline 3- methanol (0.53 g, 3 mmol) in dry acetone (25 ml), a catalytic amount of L-tartaric acid (a few crystals) was added. The reaction mixture was left to stand at room temperature for 24 hours and then evaporated to dryness. The pale-yellow oily product was dissolved in methanol (2 ml) and was converted to the crystalline dihydrochloride salt by using ethanol containing 22% hydrogen chloride (1 ml) and diethyl ether. The crystals were filtered off and recrystallized from methanol/diethyl ether. ¹³C-NMR: see Method 8a.

Method 8c: 2-Amino-l,2,3,4-tetrahydroisoquinoline 3-methanol hydrochloride (0.64 g, 3 mmol) was suspended in dry acetone (40 ml). The reaction mixture was stirred at room temperature for 36 hours and then evaporated to dryness. The semisolid residue crystallized on treatment with methanol/diethyl ether. The crystals were filtered off and recrystallized from metharidl diethyl ether. ^ϋC-NMR: see Method 8a.

Example 9 t' «* 2-[l-methyl-2-(4-pyridylmethylene)hydrazino]-l-cycIohexanoI

To a solution of trans 2-(l-methylhydrazino)-l-cyclohexanol (0.43 g, 3 mmol) in dry methanol (15 ml) 4-pyridinecarboxaldehyde (0.33 g, 3 mmol) was added. The reaction mixture was left to stand at room temperature for 2 hours then evaporated in vacou. The oily residue was crystallized on treatment with a mixture of n-hexane and diethyl ether. The separated crystals were filtered off and recrystallized from a mixture of diisopropyl ether and ethyl acetate. The physical data are given in Table 3.

1H NMR (400 MHz, CDC1₃) δ 1.20-1.45 (4H, om, (CH₂)₄), 1.77 (2H, m, (CH₂)₄),

1.86 (1Η, m (CH₂)₄), 2.14 (1Η, m (CH₂)₄), 2.99 (3Η, s, NCH₃), 3.10 (2H, m, NCH),

3.96 (IH, m, OCH), 7.06 (1Η, s, N=CH), 7.36 (m, 2Η, C5H ), 8.47 (m, 2H,

CsHtN).

¹³C NMR (100.6 MHz, CDC1₃) δ 24.7, 25.4, 29.2, 33.9, 36.8, 71.6, 73.7, 119.9

(N=C), 127.2, 150.2. Table 1. Physical data of the synthesized racemic compounds

Example 10

In Vitro Inhibition of VAP-1 SSAO Activity

VAP-1 SSAO activity was measured using the coupled colourimetric method essentially as described for monoamine oxidase and related enzymes (Holt, A., et al, Anal Biochem. 244:314-392 (1997)). Recombinant human VAP-1

SSAO expressed in Chinese Hamster Ovary (CHO) cells was used as a source of

VAP-1 SSAO for activity measurements. Native CHO cells have negligible SSAO activity. These cells and their culture have previously been described (Smith, D. J., et al. , J. Exp. Med. 188:11-21 (1998)). A cell lysate was prepared by suspending approximately 3.6 x 10⁸ cells in 25ml lysis buffer (150mMNaCl, lOmMTris-Base pH 7.2, 1.5 mM MgCl₂, 1% NP40, 1% Aprotinin, and ImM PMSF) and incubating at 4°C overnight on a rotating table. The lysate was clarified by centrifugation at 21200 g for 30 min at 4°C and the supernatant used directly in the assay. The VAP-1 SSAO assay was performed in 96 well microtitre plates as follows. To each well was added a predetermined amount of inhibitor if required. The amount of inhibitor varied in each assay but was generally at a final concentration of between 10 nM and 2.5 mM. Controls lacked inhibitor. The inhibitor was in a total volume of 20 :1 in water. The following reagents were then added. 0.2M potassium phosphate buffer pH 7.6 to a total reaction volume of 200μl, 45 μl of freshly made chromogenic solution containing ImM 2,4- dichlorophenol, 500 μM 4-aminoantipyrine and 4 :g/ml horseradish peroxidase and an amount of CHO cell lysate containing VAP-1 SSAO that caused a change of 0.6 A₄₉₀ per h. This was within the linear response range of the assay. The plates were incubated for 30 min at 37°C and the background absorbance measured at 490 nm using a Wallac Victor II multilabel counter. To initiate the enzyme reaction 20 μl 1 OmM benzylamine (final concentration = ImM) was added and the plate incubated for 1 h at 37°C. The increase in absorbance, reflecting VAP-1 SSAO activity, was measured at 490nm. Inhibition was presented as percent inhibition compared to control after correcting for background absorbance. Example 11 Comparison of VAP-1 SSAO activity versus total human MAO activity

Human MAO was prepared from human liver by homegenising liver samples 1 :25 (w/v) in ice-cold potassium phosphate buffer (0.2 M, pH 7.6) with a hand held Ten Broeck homogeniser. After centrifugation at 1000 g and 4°C for 15 min the supernatant was carefully withdrawn and used as the source of MAO. Total MAO activity was measured in a similar way as for VAP-1 SSAO except that 2,4-dichlorophenol was replaced by ImM vanillic acid. To each well was added a predetermined amount of inhibitor if required. The amount of inhibitor varied in each assay but was generally at a final concentration of between 10 nM and 2.5 mM. Controls lacked inhibitor. The inhibitor was in a total volume of 20 :1 in water. The following reagents were then added. 0.2 M potassium phosphate buffer pH 7.6 for a total reaction volume of 300 μl, 50 μl of freshly made chromogenic solution (as above) and 50 μl of MAO preparation. The plates were incubated for 30 min at 37°C and the background absorbance measured at 490 nm using a Wallac Victor II multilabel counter. To initiate the enzyme reaction 20 μl of 5 mM tyramine (final concentration 0.5 mM) was added and the plate incubated for 1 h at 37°C. The increase in absorbance, reflecting MAO activity, was measured at 490nm. Inhibition was presented as percent inhibition compared to control after correcting for background absorbance. Clorgyline and pargyline (inhibitors of MAO-A and -B respectively) at 0.5 μM were added to some wells as positive controls for MAO inhibition.

The ability of compounds of Examples 1 to 8 to inhibit VAP-1 SSAO activity with specificity for VAP-1 SSAO over human MAO is shown in Table 3. The results indicate that the compounds of the invention (or their hydrazino alcohol degradation products) are specific inhibitors of human VAP-1 SSAO activity, and are more potent inhibitors of VAP-1 SSAO than previously known inhibitors of VAP-1 SSAO such as semicarbazide. The compounds of the present invention are therefore expected to have therapeutic utility in the treatment of diseases and conditions in which the the SSAO activity of the human adhesion molecule VAP-1 plays a role.

Table 3

Having now fully described this invention, it will be understood to those of ordinary skill in the art that the same can be performed within a wide and equivalent range of conditions, formulations, and other parameters without affecting the scope of the invention or any embodiment thereof. All patents and publications cited herein are fully incorporated by reference herein in their entirety.

Claims (55)

Whatls Claimed Is:

1. Use of an oxadiazine compound ofFormula /:

/

or a tautomer, isomer, hydrazino alcohol degradation product, or a pharmaceutically acceptable solvate, hydrate, or salt thereof; wherein: R¹ is hydrogen or Ci-C alkyl;

R² is hydrogen, C₁-C alkyl, C₂-C alkenyl, aralkyl, C₂-C6 alkanoyl, C₃-C₆ alkenoyl, or C₇-Cn aroyl which is optionally substituted;

R³, R⁴, R⁵, and R⁶, which can be the same or different, are hydrogen, C C alkyl or optionally substituted aryl; or any two of said substituents R³, R⁴, R⁵, and R⁶ are taken together with the carbon atoms to which they are attached to form an optionally substituted carbocyclic or hetercyclic ring; or R² and R³ are taken together with the atoms to which they are attached to form an optionally substituted carbocyclic or heterocyclic ring; and R⁷ is hydrogen, Ci-C₄ alkyl, aryl, substituted aryl, heteroaryl, or aralkyl; R⁸ is Ci- C alkyl, aryl, substituted aryl, heteroaryl, or aralkyl; or R⁷ and R⁸ are taken together with the carbon atoms to which they are attached to form an optionally substituted 5-12 membered carbocyclic or heterocyclic ring, for the manufacture of a pharmaceutical preparation for inhibiting copper-containing amine oxidase.

2. The use of a compound as defined in claim 1 for the manufacture of a pharmaceutical preparation for the treatment of an inflammatory disease or condition, a disease related to carbohydrate metabolism, a disease related to aberrations in adipocyte differentiation or function or smooth muscle cell function, or a vascular disease.

3. The use of claim 1 or 2, wherein R² is benzyl substituted with alkyl, nitro, methoxy, or halogen.

4. The use of claim 3, wherein R² is benzyl substituted at the para position with methyl, nitro, methoxy, or chlorine.

5. The use of claim 1 or 2, wherein two of R³, R⁴, R⁵ and R⁶ are taken together with the carbon atoms to which they are attached to form a 5-7 membered carbocyclic or heterocyclic ring.

6. The use of claim 5, wherein R⁴ and R⁶ are taken together with the carbon atoms to which they are attached to form a 5-7 membered carbocyclic or heterocyclic ring, and R³ and R⁵ are each hydrogen.

7. The use of claim 6, wherein said 5-7 membered ring is selected from the group consisting of cyclopentane, cyclohexane, 4-methyl-cyclohexane, and cycloheptane.

8. The use of claim 1 or 2, wherein R² and R³ are taken together with the carbon atoms to which they are attached to form an optionally substituted heterocyclic ring.

9. The use of claim 8, wherein the substituents R² and R³ are taken together to form a 5 to 6 membered, saturated, nitrogen-containing heterocyclic ring which is optionally substituted with alkyl.

10. The use of claim 8, wherein R² and R³ are taken together to form an optionally substituted heterocyclic ring selected from the group consisting of 1,2,3,4-tetrahydroquinoline, 1,2,3,4, -tetrahydroisoquinoline, 2,3-dihydroindole, piperidine, and 6,7-dimethoxy-l,2,3,4-tetrahydro-isoquinoline.

11. The use of claim 1 or 2, wherein R⁷ and R⁸ are taken together to form an optionally substituted carbocyclic or heterocyclic ring.

12. The use of claim 11, wherein said carbocyclic or heterocyclic ring is substituted with alkyl, aralkyl, or substituted aralkyl.

13. The use of claim 12, wherein said carbocyclic or heterocyclic ring is N-benzylpiperidine.

14. The use of claim 2, wherein said inflammatory disease or condition is a connective tissue inflammatory disease or condition.

15. The use of claim 14, wherein said connective tissue inflammatory disease or condition is selected from the group consisting of ankylosing spondylitis, Reiter's syndrome, psoriatic arthritis, osteoarthritis or degenerative joint disease, rheumatoid arthritis, Sjδgren's syndrome, Behcet's syndrome, relapsing polychondritis, systemic lupus erythematosus, discoid lupus erythematosus, systemic sclerosis, eosinophilic fasciitis, polymyositis and dermatomyositis, polymyalgia rheumatica, vasculitis, temporal arteritis, polyarteritis nodosa, Wegener's granulomatosis, mixed connective tissue disease, and juvenile rheumatoid arthritis.

16. The use of claim 2, wherein said inflammatory disease or condition is a gastrointestinal inflammatory disease or condition.

17. The use of claim 16, wherein said gastrointestinal inflammatory disease or condition is selected from the group consisting of Crohn's disease, ulcerative colitis, irritable bowel syndrome (spastic colon), fibrotic conditions of the liver, inflammation of the oral mucosa (stomatitis), and recurrent aphtous stomatitis.

18. The use of claim 2, wherein said inflammatory disease or condition is a central nervous system inflammatory disease or condition.

19. The use of claim 18, wherein said central nervous system inflammatory disease or condition is selected from the group consisting of multiple sclerosis, Alzheimer's disease, and ischaemia-reperfusion injury associated with ischemic stroke.

20. The use of claim 2, wherein said inflammatory disease or condition is a pulmonary inflammatory disease or condition.

21. The use of claim 20, wherein said pulmonary inflammatory disease or condition is selected from the group consisting of asthma, chronic obstructive pulmonary disease, and adult respiratory distress syndrome.

22. The use of claim 2, wherein said inflammatory disease or condition is a skin inflammatory disease or condition.

23. The use of claim 22, wherein said skin inflammatory disease or condition is selected from the group consisting of contact dermatitis, atopic dermatitis, psoriasis, pityriasis rosea, lichen planus, and pityriasis rubra pilaris.

24. The use of claim 2, wherein said disease related to carbohydrate metabolism is selected from the group consisting of diabetes, atherosclerosis, vascular retinopathies, retinopathy, nephropathy, nephrotic syndrome, polyneuropathy, mononeuropathies, autonomic neuropathy, foot ulcers, joint problems, and increased risk of infection.

25. The use of claim 2, wherein said disease related to aberrations in adipocyte differentiation or function or smooth muscle cell function is selected from the group consisting of atherosclerosis and obesity.

26. The use of claim 2, wherein said vascular disease is selected from the group consisting of atheromatous ateriosclerosis, nonatheromatous ateriosclerosis, ischemic heart disease, peripheral aterial occlusion, thromboangiitis obliterans (Buerger's disease), and Raynaud's disease and phenomenon.

27. The use of claim 1 or 2, wherein said compound of Formula /is selected from the group consisting of:

9-benzyl-2-methyl-5 -oxa- 1 ,2, 9-triazaspiro [5.5 jundecane,

9-benzyl-2-methyl-4-phenyl-5-oxa-l,2,9-triazaspiro[5.5]-undecane,

(3S,4R)-9-benzyl-2,3-dimethyl-4-phenyl-5-oxa-l,2,9-triazaspiro[5.5]undecane, (3R,4S)-2,3-dimethyl-4-phenyl-5-oxa-l,2-diazaspiro[5.5]undecane,

(4aR*,8aS*)-4-methyl-2,2-pentamethylene-3,4,4a,5,6,7,8,8a-octahydro-2H-l,3,4- benzoxadiazine,

(4aR*,8aR*)-2,2,4-trimethyl-3,4,4a,5,6,7,8,8a-octahydro-2H-l,3,4- benzoxadiazine, (4aR*,8aR*)-4-benzyl-2-ethyl-2methyl-3,4,4a,5,6,7,8,8a-octahydro-2H-l,3,4- benzoxadiazine,

2,2-dimethyl-l,2,4a,5-tetrahydro-4H,10H-l,3,4-oxadiazino[4,5-δ]isoquinoline, and 2,3-dimethyl-4-phenyl-5-oxa-l,2-diazaspiro[5.5]undecane; or a pharmaceutically acceptable salt thereof.

28. The use of claim 1 or 2, wherein said compound ofFormula / is (3S,4R)-9-benzyl-2,3-dimethyl-4-phenyl-5-oxa-l,2,9-triazaspiro[5.5]undecane, (3R,4S)-2,3-dimethyl-4-phenyl-5-oxa-l,2-diazaspiro[5.5]undecane, or a pharmaceutically acceptable salt thereof.

29. A method of inhibiting a copper-containing amine oxidase, comprising contacting said amine oxidase with an inhibitory effective amount of a 1,3,4-oxadiazine compound of Formula /as defined in any of the claims 1 to 28.

30. The method of claim 29, wherein said contacting occurs in vitro.

31. The method of claim 29, wherein said contacting occurs in vivo.

32. A method of treating an inflammatory disease or condition, a disease related to carbohydrate metabolism, a disease related to aberrations in adipocyte differentiation or function or smooth muscle cell function, or a vascular disease, comprising administering to an animal in need or such treatment or prevention an effective amount of an oxadiazine compound of Formula / as defined in any on of the claims 1 to 28.

33. A compound of Formula /:

or a tautomer, isomer, or a pharmaceutically acceptable solvate, hydrate, or salt thereof, wherein:

R¹ is hydrogen, or (Ci-G alkyl;

R² is hydrogen, C C₄ alkyl, C₂-C₄ alkenyl, C₆-C₁₀ ar(d-C₄)aιkyl, C₂-C₆ alkanoyl, C₂-C₆ alkenoyl, or benzoyl, any of which may be optionally substituted with Ci-C₄ alkyl, nitro, methoxy or halogen;

R³, R⁴, R⁵, and R⁶, which can be the same or different, are hydrogen, or Ci-C alkyl or Cβ-Cio aryl, either of which is optionally substituted with Ci-C alkyl or halogen; or two of said substituents R³, R⁴, R⁵ and R⁶ are taken together with the carbon atoms to which they are attached to form a 5 to 12 membered carbocyclic or heterocyclic ring optionally substituted with Ci-C₄ alkyl or halogen; or R² and R³ are taken together with the atoms to which they are attached to form a 5 to 12 membered carbocyclic or heterocyclic ring optionally substituted with alkyl or halogen; and R⁷ is hydrogen, Cι-C₄ alkyl, Cβ-Cw aryl, substituted C₆-C₁₀ aryl, heteroaryl, or C6-C₁₀ ar(Ci-C₄)alkyl;

R⁸ is Cι-C₄ alkyl, C₆-Cι₀ aryl, substituted C₆-C₁₀ aryl, heteroaryl, or C₆-C₁₀ ar(Cι-C₄)alkyl; or R⁷ and R⁸ are taken together with the carbon atoms to which they are attached to form a 5-12 membered carbocyclic or heterocyclic ring optionally substituted with Ci-Cβ alkyl, or Cβ-Cio provided that R³ and R⁴ are not hydrogen or C₁-C₄ alkyl when R⁷ and/or

R⁸ are C1-C4 alkyl or optionally substituted phenyl, or when R⁷ and R⁸ are taken together with the carbon atom to which they are attached to form an unsubstituted

C5-C₇ cycloalkyl group.

34. The compound of claim 33, wherein R² is benzyl substituted with alkyl, nitro, methoxy, or halogen.

35. The compound of claim 34, wherein R² is benzyl substituted at the para position with methyl, nitro, methoxy, or chlorine.

36. The compound of claim 33, wherein two of R³, R⁴, R⁵ and R⁶ are taken together with the carbon atoms to which they are attached to form a 5-7 membered carbocyclic or heterocyclic ring.

37. The compound of claim 36, wherein R⁴ and R⁶ are taken together with the carbon atoms to which they are attached to form a 5-7 membered carbocyclic or heterocyclic ring, and R³ and R⁵ are each hydrogen.

38. The compound of claim 37, wherein said 5-7 membered ring is selected from the group consisting of cyclopentane, cyclohexane, 4-methyl- cyclohexane, and cycloheptane.

39. The compound of claim 33, wherein R² and R³ are taken together with the carbon atoms to which they are attached to form an optionally substituted heterocyclic ring.

40. The compound of claim 39, wherein the substituents R² andR³ are taken together to form a 5 to 6 membered, saturated, nitrogen-containing heterocyclic ring which is optionally substituted with alkyl.

41. The compound of claim 39, wherein R² and R³ are taken together to form an optionally substituted heterocyclic ring selected from the group consisting of 1,2,3,4-tetrahydroquinoline, 1,2,3,4,-tetrahydroisoquinoline, 2,3- dihydroindole, piperidine, and 6,7-dimethoxy-l,2,3,4-tetrahydro-isoquinoline.

42. The compound of claim 33, wherein R⁷ and R⁸ are taken together to form an optionally substituted carbocyclic or heterocyclic ring.

43. The compound of claim 42, wherein said carbocyclic or heterocyclic ring is substituted with alkyl, aralkyl, or substituted aralkyl.

44. The compound of claim 43, wherein said carbocyclic or heterocyclic ring is N-benzylpiperidine.

45. A compound of claim 33, which is selected from the group consisting of:

9-benzyl-2-methyl-5 -oxa- 1,2, 9-triazaspiro [5.5 ]undecane,

9-benzyl-2-methyl-4-phenyl-5-oxa-l,2,9-triazaspiro[5.5]-undecane, (3S,4R)-9- benzyl-2,3-dimethyl-4-phenyl-5-oxa-l,2,9-triazaspiro[5.5]undecane,

(4aR*,8aS*)-4-methyl-2,2-pentamethylene-3,4,4a,5,6,7,8,8a-octahydro-2H-l,3,4- benzoxadiazine,

(4aR*,8aR*)-2,2,4-trimethyl-3,4,4a,5,6,7,8,8a-octahydro-2H-l,3,4- benzoxadiazine, (4aR*,8aR*)-4-benzyl-2-ethyl-2methyl-3,4,4a,5,6,7,8,8a-octahydro-2H-l,3,4- benzoxadiazine, and

2,2-dimethyl-l,2,4a,5-tetrahydro-4H,10H-l,3,4-oxadiazino[4,5-έ]isoquinoline; or a pharmaceutically acceptable salt thereof.

46. A pharmaceutical composition comprising a compound of any one of claims 33-45 and a pharmaceutically acceptable carrier or diluent.

47. A compound of any one of the claims 33-45 for therapeutical use.

48. A process for preparing a 1,3,4-oxadiazine compound of claim 33, comprising: reacting a hydrazino alcohol ofFormula II:

with a ketone ofFormula TV:

IV to form a 1,3,4-oxadiazine ofFormula I:

I or a tautomer, isomer, solvate, hydrate, or pharmaceutically acceptable salt thereof, wherein:

R¹ is hydrogen, or (Ci-C₄)alkyl; R² is hydrogen, C1-C4 alkyl, C₂-C₄ alkenyl, C₆-Cι₀ C₂-C₆ alkanoyl, C₂-C6 alkenoyl, or benzoyl, any of which may be optionally substituted with CrC₄ alkyl, nitro, methoxy or halogen;

R³, R⁴, R⁵, and R⁶, which can be the same or different, are hydrogen, or C:ι-C₄ alkyl or Cβ-Cw aryl, either of which is optionally substituted with Ci-C₄ alkyl or halogen; or two of said substituents R³, R⁴, R⁵ and R⁶ are taken together with the carbom atoms to which they are attached to form a 5 to 12 membered carbocyclic or heterocyclic ring optionally substituted with C1-C4 alkyl or halogen; or R² and R³ are taken together with the atoms to which they are attached to form a 5 to 12 membered carbocyclic or heterocyclic ring optionally substituted . with Ci-C₆ alkyl or halogen; and

R⁷is hydrogen, Ci-C₄ alkyl, Cβ-Cio aryl, substituted C6-Cio aryl, heteroaryl, or Cβ-Cio ar(C₁-C₄)alkyl; R⁸ is C1-C4 alkyl, C6-C₁₀ aryl, substituted Cβ-Cio aryl, heteroaryl, or C6-C₁₀ ar(Cι-C4)alkyl; or R⁷ and R⁸ are taken together with the carbon atoms to which they are attached to form a 5-12 membered carbocyclic or heterocyclic ring optionally substituted with Ci-C₆ alkyl, or Cβ-Cio ar(Cι-C4)alkyl.

49. A process for preparing a 1,3,4-oxadiazine compound of claim 33, comprising: reacting a hydrazino alcohol of formula II:

with an acetal ofFormula V:

V to form a 1 1,3,4-oxadiazone ofFormula I:

' or a tautomer, isomer, solvate, hydrate, or pharmaceutically acceptable salt thereof, wherein:

R¹ is hydrogen, or (C₁-C₄)alkyl;

R² is hydrogen, Ci-C₄ alkyl, C₂-C₄ alkenyl, Cβ-Cio ar(Cι-C )alkyl, C₂-C₆ alkanoyl, C₂-Cδ alkenoyl, or benzoyl, any of which may be optionally substituted with C₁-C4 alkyl, nitro, methoxy or halogen;

R³, R⁴, R⁵, and R⁶, which can be the same or different, are hydrogen, or -C4 alkyl or Cβ-Cio aryl, either of which is optionally substituted with C C4 alkyl or halogen; or two of said substituents R³, R⁴, R⁵ and R⁶ are taken together with the carbom atoms to which they are attached to form a 5 to 12 membered carbocyclic or heterocyclic ring optionally substituted with C₁-C₄ alkyl or halogen; or R² and R³ are taken together with the atoms to which they are attached to form a 5 to 12 membered carbocyclic or heterocyclic ring optionally substituted with C Cδ alkyl or halogen; and

R⁷ is hydrogen, C₁-C₄ alkyl, C6-C₁₀ aryl, substituted C₆-Cι₀ aryl, heteroaryl, or C6-C₁₀ ar(C₁-C₄)alkyl; R⁸ is Ci-C4 alkyl, C6-C₁₀ aryl, substituted C₆-Cιo aryl, heteroaryl, or C6-C₁₀ ar(Ci-C₄)alkyl; or R⁷ and R⁸ are taken together with the carbon atoms to which they are attached to form a 5-12 membered carbocyclic or heterocyclic ring optionally substituted with C Cβ alkyl, or C₆-C₁₀ ar(Ci-C₄)alkyl.

50. The process of claim 48 or claim 49, wherein said reacting is done in the presence of an acid or base catalyst.

51. The process of claim 48 or claim 49, wherein said reacting is done in the presence of an adsorbent of water.

52. The process of claim 50, wherein said acidic catalyst is hydrochloric, -toluenesulfonic, acetic, tartaric or oxalic acid.

53. The process of claim 50, wherein said acidic catalyst is an acid ion- exchange resin suitable for non-aqueous catalysis.

54. The process of claim 50, wherein said basic catalyst is triethylamine.

55. A process for preparing a 1,3,4-oxadiazine compound of claim 33, comprising: reacting an amino alcohol ofFormula HI:

III with an oxaziridine ofFormula VI:

VI to form a 1,3,4-oxadiazine ofFormula I:

I or a tautomer, isomer, solvate, hydrate, or pharmaceutically acceptable salt thereof, wherein:

R¹ is hydrogen, or (Ci-C₄)alkyl;

R² is hydrogen, Ci-C4 alkyl, C₂-C alkenyl, Cβ-Cio ar(Cι-C4)alkyl, C₂-C₆ alkanoyl, C₂-C6 alkenoyl, or benzoyl, any of which may be optionally substituted with C1-C4 alkyl, nitro, methoxy or halogen;

R³, R⁴, R⁵, and R⁶, which can be the same or different, are hydrogen, or Ci-C₄ alkyl or Cβ-Cio aryl, either of which is optionally substituted with Ci-C₄ alkyl or halogen; or two of said substituents R³, R⁴, R⁵ and R⁶ are taken together with the carbom atoms to which they are attached to form a 5 to 12 membered carbocyclic or heterocyclic ring optionally substituted with C₁-C₄ alkyl or halogen; or R² and R³ are taken together with the atoms to which they are attached to form a 5 to 12 membered carbocyclic or heterocyclic ring optionally substituted with Ci-Cβ alkyl or halogen; and R⁷ is hydrogen, C1-C4 alkyl, C₆-C₁₀ aryl, substituted C₆-Cιo aryl, heteroaryl, or C₆-C₁₀ ar(Cι-C4)alkyl; R⁸ is Ci-C alkyl, C₆-Cιo aryl, substituted C₆-Cιo aryl, heteroaryl, or Cβ-Cio ar(Cι-C₄)alkyl; or R⁷ and R⁸ are taken together with the carbon atoms to which they are attached to form a 5-12 membered carbocyclic or heterocyclic ring optionally substituted with Ci-C₆ alkyl, or C₆-C₁₀ ar(Ci-C4)alkyl.