`
`(19) World Intellectual Property Organization
`International Bureau
`
`(43) International Publication Date
`16 January 2003 (16.01.2003)
`
` (10) International Publication Number
`
`WO 03/004498 Al
`
`(51) International Patent Classification’:
`A61K 31/4985, A61P 3/10
`
`C0O7D 487/04,
`
`(74) Common Representative: MERCK & CO., INC.; 126
`East Lincoln Avenue, Rahway, NJ 07065-0907 (US).
`
`(21) International Application Number:©PCT/US02/21349
`(81) Designated States (national): AE, AG, AL, AM,AT, AU,
`AZ, BA, BB, BG, BR, BY, BZ, CA, CH, CN, CO, CR, CU,
`CZ, DE, DK, DM, DZ, EC, EE, ES, FI, GB, GD, GE, GH,
`GM,HR,HU,ID,IL,IN,IS, JP, KE, KG, KR, KZ, LC, LK,
`LR, LS, LT, LU, LV, MA, MD, MG, MK, MN, MW, Mx,
`MZ, NO, NZ, OM, PH, PL, PT, RO, RU, SD, SE, SG,SI,
`SK, SL, TJ, TM, TN, TR, TT, TZ, UA, UG, US, UZ, VN,
`YU, ZA, ZM, ZW.
`
`(22) International Filing Date:
`
`5 July 2002 (05.07.2002)
`
`(25) Filing Language:
`
`(26) Publication Language:
`
`English
`
`English
`
`(30) Priority Data:
`60/303 ,474
`
`6 July 2001 (06.07.2001)
`
`US
`
`(71) Applicant (for all designated States except US): MERCK
`& CO., INC. [US/US]; 126 East Lincoln Avenue, Rahway,
`NJ 07065-0907 (US).
`
`(72) Inventors; and
`(75) Inventors/Applicants (for US only): EDMONDSON,
`Scott, D. [US/US]; 126 East Lincoln Avenue, Rahway, NJ
`07065-0907 (US). FISHER, Michael, H. [US/US]; 126
`East Lincoln Avenue, Rahway, NJ 07065-0907 (US). KIM,
`Dooseop [KR/US]; 126 East Lincoln Avenue, Rahway,
`NJ 07065-0907 (US). MACCOSS, Malcolm [GB/US];
`126 East Lincoln Avenue, Rahway, NJ 07065-0907 (US).
`PARMEE, Emma, R. [GB/US]; 126 East Lincoln Av-
`enue, Rahway, NJ 07065-0907 (US). WEBER, Ann,
`E.
`[US/US]; 126 East Lincoln Avenue, Rahway, NJ
`07065-0907 (US). XU, Jinyou [CN/US]; 126 East Lincoln
`Avenue, Rahway, NJ 07065-0907 (US).
`
`(84) Designated States (regional): ARIPO patent (GH, GM,
`KE, LS, MW, MZ, SD, SL, SZ, TZ, UG, ZM, ZW),
`Eurasian patent (AM, AZ, BY, KG, KZ, MD, RU, TJ, TM),
`European patent (AT, BE, BG, CH, CY, CZ, DE, DK, EE,
`ES, FI, FR, GB, GR, IE, IT, LU, MC, NL, PT, SE, SK,
`TR), OAPIpatent (BF, BJ, CE, CG, CI, CM, GA, GN, GQ,
`GW, ML, MR, NE, SN, TD, TG).
`
`Published:
`
`with international search report
`before the expiration of the time limit for amending the
`claims and to be republished in the event of receipt of
`amendments
`
`For two-letter codes and other abbreviations, refer to the "Guid-
`ance Notes on Codes andAbbreviations" appearing at the begin-
`ning ofeach regular issue ofthe PCT Gazette.
`
`BETA-AMINO TETRAHYDROIMIDAZO (1, 2-A) PYRAZINES AND TETRAHYDROTRIOAZOLO (4, 3-A)
`(54) Title:
`PYRAZINES AS DIPEPTIDYL PEPTIDASE INHIBITORS FOR THE TREATMENT OR PREVENTION OF DIABETES
`
`/004498Al
`
`2 (57) Abstract: The present invention is directed to compoundswhichare inhibitors ofthe dipeptidyl peptidase-[V enzyme ("DP-IV
`
`inhibitors") and which are useful in the treatment or prevention of diseases in which the dipeptidyl peptidase-[V enzymeis involved,
`such as diabetes and particularly type 2 diabetes. The invention is also directed to pharmaceutical compositions comprising these
`compoundsandthe use of these compounds and compositionsin the prevention or treatment of such diseases in which the dipeptidyl
`
`S peptidase-IV enzymeis involved.
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`BETA-AMINO TETRAHYDROIMIDAZO (1,2-A) PYRAZINES AND TETRAHYDROTRIAZOLO (4,3~-A)
`PYRAZINES AS DIPEPTIDYL PEPTIDASE INHIBITORS FOR THE TREATMENT OR PREVENTION
`OF DIABETES
`
`5
`
`BACKGROUND OF THE INVENTION
`
`10
`
`15
`
`Diabetes refers to a disease process derived from multiple causative
`factors and characterized by elevated levels of plasma glucose or hyperglycemia in the
`fasting state or after administration of glucose during an oral glucose tolerancetest.
`Persistent or uncontrolled hyperglycemia is associated with increased and premature
`morbidity and mortality. Often abnormal glucose homeostasis is associated both
`directly and indirectly with alterations of the lipid, lipoprotein and apolipoprotein
`metabolism and other metabolic and hemodynamic disease. Therefore patients with
`Type 2 diabetes mellitus are at especially increased risk of macrovascular and
`microvascular complications, including coronary heart disease, stroke, peripheral
`vascular disease, hypertension, nephropathy, neuropathy, and retinopathy. Therefore,
`therapeutical control of glucose homeostasis, lipid metabolism and hypertension are
`critically important in the clinical management and treatment of diabetes mellitus.
`There are two generally recognized forms of diabetes. In type 1
`diabetes, or insulin-dependent diabetes mellitus IDDM), patients producelittle or no
`insulin, the hormone which regulates glucose utilization. In type 2 diabetes, or
`noninsulin dependent diabetes mellitus (NIDDM),patients often have plasmainsulin
`levels that are the same or even elevated compared to nondiabetic subjects; however,
`these patients have developedaresistance to the insulin stimulating effect on glucose
`and lipid metabolism in the main insulin-sensitive tissues, which are muscle, liver and
`adipose tissues, and the plasma insulin levels, while elevated, are insufficient to
`overcome the pronouncedinsulin resistance.
`Insulin resistance is not primarily due to a diminished numberof
`insulin receptors but to a post-insulin receptor binding defect that is not yet
`understood. This resistance to insulin responsiveness results in insufficient insulin
`activation of glucose uptake, oxidation and storage in muscle and inadequate insulin
`repression oflipolysis in adipose tissue and of glucose production and secretion in the
`liver.
`
`20
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`30
`
`The available treatments for type 2 diabetes, which have not changed
`substantially in many years, have recognized limitations. While physical exercise and
`reductions in dietary intake of calories will dramatically improve the diabetic
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`condition, compliance with this treatment is very poor because of well-entrenched
`sedentary lifestyles and excess food consumption, especially of foods containing high
`amounts of saturated fat. Increasing the plasma level of insulin by administration of
`sulfonylureas (e.g. tolbutamide and glipizide) or meglitinide, which stimulate the
`pancreatic B—cells to secrete more insulin, and/or by injection of insulin when
`sulfonylureas or meglitinide becomeineffective, can result in insulin concentrations
`high enoughto stimulate the very insulin-resistant tissues. However, dangerously low
`levels of plasma glucose can result from administration of insulin or insulin
`secretagogues (sulfonylureas or meglitinide), and an increased level of insulin
`resistance due to the even higher plasma insulin levels can occur. The biguanides
`increase insulin sensitivity resulting in some correction of hyperglycemia. However,
`the two biguanides, phenformin and metformin, can induce lactic acidosis and
`nausea/diarrhea. Metformin has fewer side effects than phenformin and is often
`prescribed for the treatment of Type 2 diabetes.
`Theglitazones(i.e. 5-benzylthiazolidine-2,4-diones) are a more
`recently described class of compounds with potential for ameliorating many
`symptomsof type 2 diabetes. These agents substantially increase insulin sensitivity in
`muscle,liver and adipose tissue in several animal models of type 2 diabetes resulting
`in partial or complete correction of the elevated plasma levels of glucose without
`occurrence of hypoglycemia. The glitazones that are currently marketed are agonists
`of the peroxisomeproliferator activated receptor (PPAR), primarily the PPAR-gamma
`subtype. PPAR-gammaagonism is generally believed to be responsible for the
`improved insulin sensititization that is observed with the glitazones. Newer PPAR
`agonists that are being tested for treatment of Type II diabetes are agonists of the
`alpha, gammaor delta subtype, or a combination of these, and in many cases are
`chemically different from the glitazones(i.e., they are not thiazolidinediones).
`Serious side effects (e.g. liver toxicity) have occurred with someof the glitazones,
`such as troglitazone.
`Additional methodsoftreating the disease arestill under investigation.
`New biochemical approachesthat have been recently introduced orare still under
`developmentinclude treatment with alpha-glucosidase inhibitors(e.g. acarbose) and
`protein tyrosine phosphatase-1B (PTP-1B) inhibitors.
`Compoundsthat are inhibitors of the dipeptidyl peptidase-IV ("DP-IV"
`or "DPP-IV") enzymeare also under investigation as drugs that may be useful in the
`treatment of diabetes, and particularly type 2 diabetes. See for example WO
`-2-
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`97/40832, WO 98/19998, U.S. Patent No. 5,939,560, Bioorg. Med. Chem. Lett., 6(10),
`1163-1166 (1996); and Bioorg. Med. Chem. Lett., 6(22), 2745-2748 (1996). The
`usefulness of DP-IV inhibitors in the treatment of type 2 diabetes is based on the fact
`that DP-IV in vivo readily inactivates glucagon like peptide-1 (GLP-1) and gastric
`inhibitory peptide (GIP). GLP-1 and GIP are incretins and are produced when foodis
`consumed. Theincretins stimulate production of insulin. Inhibition of DP-IV leads to
`decreased inactivation of the incretins, and this in turn results in increased
`effectiveness of the incretins in stimulating production of insulin by the pancreas.
`DP-IV inhibition therefore results in an increased level of serum insulin.
`
`Advantageously, since the incretins are produced by the body only when food is
`consumed, DP-IV inhibition is not expected to increase the level of insulin at
`inappropriate times, such as between meals, which can lead to excessively low blood
`sugar (hypoglycemia). Inhibition of DP-IV is therefore expected to increase insulin
`without increasing the risk of hypoglycemia, which is a dangerousside effect
`associated with the use of insulin secretagogues.
`DP-IV inhibitors also have other therapeuticutilities, as discussed
`herein. DP-IV inhibitors have not been studied extensively to date, especially for
`utilities other than diabetes. New compoundsare needed so that improved DP-IV
`inhibitors can be found for the treatment of diabetes and potentially other diseases and
`
`10
`
`15
`
`20
`
`conditions.
`
`SUMMARY OF THE INVENTION
`
`The present inventionis directed to compounds whichare inhibitors of
`the dipeptidyl peptidase-IV enzyme("DP-IV inhibitors") and which are useful in the
`treatment or prevention of diseases in which the dipeptidyl peptidase-IV enzymeis
`involved, such as diabetes and particularly type 2 diabetes. The invention is also
`directed to pharmaceutical compositions comprising these compoundsandthe use of
`these compounds and compositions in the prevention or treatment of such diseases in
`which the dipeptidyl peptidase-IV enzymeis involved.
`
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`DETAILED DESCRIPTION OF THE INVENTION
`
`The present invention is directed to compoundsof the formulaI:
`
`anAJLN=N
`
`NH, O
`
`wherein:
`Ar is phenyl which is unsubstituted or substituted with 1-5 of R3, wherein R3 is
`independently selected from the group consisting of:
`(1)
`halogen,
`(2)
`C1-6alkyl, which is linear or branched and is unsubstituted or
`
`substituted with 1-5 halogens,
`OC}1-6alkyl, which is linear or branched and is unsubstituted or
`
`substituted with 1-5 halogens, and
`CN;
`
`(3)
`
`(4)
`
`X is selected from the group consisting of:
`(1)
`N, and
`(2)
`CR2;
`
`RI and R2 are independently selected from the group consisting of:
`(1)
`hydrogen,
`(2)
`CN,
`(3)
`C1-10alkyl, which is linear or branched and which is unsubstituted or
`
`substituted with 1-5 halogens or phenyl, which is unsubstituted or
`substituted with 1-5 substituents independently selected from halogen,
`CN, OH, R4, OR4, NHSO9R4, SO2R4, CO2H, and CO2C1-¢alkyl,
`wherein the CO2C1-galkylis linear or branched,
`
`(4)
`
`phenyl which is unsubstituted or substituted with 1-5 substituents
`independently selected from halogen, CN, OH, R4, OR4, NHSO2R4,
`SOR4, CO2H, and CO2C1-¢alkyl, wherein the CO2C1-6alkylis
`
`linear or branched, and
`
`-4-
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`(6)
`
`a 5- or 6-membered heterocycle which maybe saturated or unsaturated
`comprising 1-4 heteroatoms independently selected from N, S and O,
`the heterocycle being unsubstituted or substituted with 1-3 substituents
`independently selected from oxo, OH,halogen, Cj-6alkyl, and
`OC -6alkyl, wherein the Cy-¢galkyl and OC1-¢alkyl are linear or
`
`branched and optionally substituted with 1-5 halogens;
`
`R4 is Cy-6alkyl, which is linear or branched and which is unsubstituted or substituted
`
`with 1-5 groups independently selected from halogen, CO2H, and
`CO2C1-6alkyl, wherein the CO2C1-6alkyl is linear or branched,
`
`and pharmaceutically acceptable salts thereof and individual diastereomers thereof.
`
`5
`
`10
`
`An embodimentof the present invention includes compoundsof the
`15=formula Ja:
`
`anAJkN=N
`
`NH, O
`
`wherein X, Ar and R! are defined herein;
`and pharmaceutically acceptable salts and individual diastereomersthereof.
`
`la
`
`20
`
`the formula Ib:
`
`Another embodimentof the present invention includes compounds of
`
`NH, O
`
`wrANNN
`
`25
`
`wherein Ar and R! are definedherein;
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`and pharmaceutically acceptable salts and individual diastereomers thereof.
`
`Another embodiment of the present invention includes compounds of
`
`the formulaIc:
`
`NHs O
`
`wrNANen
`One
`
`10
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`15
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`20
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`25
`
`Ic
`wherein Ar, R! and R2 are defined herein;
`and pharmaceutically acceptable salts thereof and individual diastereomers thereof.
`
`In the present invention it is preferred that Ar is phenyl whichis
`unsubstituted or substituted with 1-5 substitutents which are independently selected
`from the group consisting of:
`(1)
`fluoro,
`(2)
`bromo, and
`(3)
`CF3.
`
`In the present invention it is more preferred that Ar is selected from the
`group consistingof:
`(1)
`phenyl,
`(2)
`2-fluorophenyl,
`(3)
`3,4-difluorophenyl,
`(4)
`2,5-difluorophenyl,
`(5)
`2,4,5-trifluoropheny]l,
`(6)
`2-fluoro-4-(triflouromethyl)phenyl, and
`(7)
`4-bromo-2,5-difluorophenyl.
`
`In the present invention it is preferred that R!is selected from the
`group consistingof:
`(1)
`
`hydrogen, and
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`(2)
`
`Cy-¢alkyl, which is linear or branched and whichis
`
`unsubstituted or substituted with phenyl or 1-5 fluoro.
`
`In the present inventionit is more preferred that R! is selected from the
`group consisting of:
`hydrogen,
`(1)
`(2)—methyl,
`(3)
`ethyl,
`(4)
`CF3,
`(5)
`CH2CF3,
`(5)
`CF2CF3
`
`10
`
`(6)
`(7)
`
`phenyl, and
`benzyl.
`
`In the present invention it is more preferred that R!is selected from the
`group consisting of:
`(1)
`(2)
`(3)
`(4)
`
`hydrogen,
`methyl,
`ethyl,
`CF3, and
`
`(5)
`
`CH2CF3.
`
`In the present invention it is even more preferred that R1 is hydrogen
`
`or CF3,
`
`In the present inventionit is preferred that R2 is selected from:
`(1)
`hydrogen,
`(2)
` Cy-Galkyl, whichis linear or branched and whichis
`
`(3)
`
`unsubstituted or substituted with 1-5 fluoro,
`phenyl, which is unsubstituted or substituted with 1-3
`substituents independently selected from fluoro, OCH3, and
`OCF3.
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`In the present invention it is more preferred that R2is selected from the
`group consisting of:
`(1)
`(2)
`(3)
`(4)
`(5)
`
`hydrogen,
`methyl,
`ethyl,
`C3,
`CH2CF3,
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`(5)
`
`(6)
`(7)
`(8)
`(9)
`(10)
`
`CF2CF3
`
`phenyl,
`(4-methoxy)phenyl,
`(4-trifluoromethoxy)phenyl,
`4-fluorophenyl, and
` 3,4-difluorophenyl.
`
`In the present invention it is even more preferred that R2 is CF3 or
`
`CF2F3.
`
`In the present inventionit is preferred that R3 is F, Br or CF3.
`
`The compoundsof the present invention may contain one or more
`asymmetric centers and can thus occur as racemates and racemic mixtures, single
`enantiomers, diastereomeric mixtures and individual diastereomers. The compounds
`of the instant invention have one asymmetric center at the beta carbon atom.
`Additional asymmetric centers may be present depending upon the nature of the
`various substituents on the molecule. Each such asymmetric center will
`independently produce two optical isomers and it is intended thatall of the possible
`optical isomers and diastereomers in mixtures and as pureor partially purified
`compoundsare included within the ambit of this invention. The presentinvention is
`meant to comprehendall such isomeric forms of these compounds.
`Someof the compounds described herein contain olefinic double
`bonds, and unless specified otherwise, are meant to include both E and Z geometric
`isomers.
`_
`
`Someof the compounds described herein may exist as tautomers,
`which havedifferent points of attachment of hydrogen accompanied by one or more
`double bondshifts. For example, a ketone and its enol form are keto-enol tautomers.
`
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`Theindividual tautomers as well as mixtures thereof are encompassed with
`compoundsof the present invention.
`Formula I showsthe structure of the class of compounds without
`preferred stereochemistry. Formula Ia shows the preferred sterochemistry at the
`carbon atom that is attached to the amine group of the beta amino acid from which
`these compoundsare prepared.
`The independent syntheses of these diastereomers or their
`chromatographic separations may be achieved as knownin the art by appropriate
`modification of the methodology disclosed herein. Their absolute stereochemistry
`may be determined bythe x-ray crystallography of crystalline products or crystalline
`intermediates which are derivatized, if necessary, with a reagent containing an
`asymmetric center of known absolute configuration.
`If desired, racemic mixtures of the compounds may be separated so
`that the individual enantiomers are isolated. The separation can be carried out by
`methods well knownin the art, such as the coupling of a racemic mixture of
`compounds to an enantiomerically pure compound to form a diastereomeric mixture,
`followed by separation of the individual diastereomers by standard methods, such as
`fractional crystallization or chromatography. The coupling reaction is often the
`formation of salts using an enantiomerically pure acid or base. The diasteromeric
`derivatives may then be converted to the pure enantiomers by cleavage of the added
`chiral residue. The racemic mixture of the compoundscan also be separated directly
`by chromatographic methodsutilizing chiral stationary phases, which methods are
`well knownin theart.
`Alternatively, any enantiomer of a compound maybe obtained by
`stereoselective synthesis using optically pure starting materials or reagents of known
`configuration by methods well knownin theart.
`The term "pharmaceutically acceptable salts" refers to salts prepared
`from pharmaceutically acceptable non-toxic bases or acids including inorganic or
`organic bases and inorganic or organic acids. Salts derived from inorganic bases
`include aluminum, ammonium,calcium, copper, ferric, ferrous, lithium, magnesium,
`manganic salts, manganous, potassium, sodium, zinc, and the like. Particularly
`preferred are the ammonium,calcium, magnesium, potassium, and sodium salts. Salts
`in the solid form may exist in more than onecrystal structure, and mayalso be in the
`form of hydrates. Salts derived from pharmaceutically acceptable organic non-toxic
`bases include salts of primary, secondary, and tertiary amines, substituted amines
`-9-
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`including naturally occurring substituted amines, cyclic amines, and basic ion
`exchange resins, such as arginine, betaine, caffeine, choline, N,N~-dibenzylethylene-
`diamine, diethylamine, 2-diethylaminoethanol, 2-dimethylaminoethanol,
`ethanolamine, ethylenediamine, N-ethyl-morpholine, N-ethylpiperidine, glucamine,
`glucosamine, histidine, hydrabamine, isopropylamine, lysine, methylglucamine,
`morpholine, piperazine, piperidine, polyamine resins, procaine, purines, theobromine,
`triethylamine, trimethylamine, tripropylamine, tromethamine,andthelike.
`Whenthe compoundofthe present invention is basic, salts may be
`prepared from pharmaceutically acceptable non-toxic acids, including inorganic and
`organic acids. Such acids include acetic, benzenesulfonic, benzoic, camphorsulfonic,
`citric, ethanesulfonic, fumaric, gluconic, glutamic, hydrobromic, hydrochloric,
`isethionic, lactic, maleic, malic, mandelic, methanesulfonic, mucic, nitric, pamoic,
`pantothenic, phosphoric, succinic, sulfuric, tartaric, p-toluenesulfonic acid, and the
`like. Particularly preferred are citric, hydrobromic, hydrochloric, maleic, phosphoric,
`sulfuric, fumaric, and tartaric acids.
`It will be understoodthat, as used herein, references to the compounds
`of Formula I are meantto also include the pharmaceutically acceptable salts.
`As appreciated by those of skill in the art, halo or halogen as used
`herein are intended to include fluoro, chloro, bromo and iodo. Similarly, C{-g, as in
`Cy-galkyl is defined to identify the group as having 1, 2, 3, 4, 5, 6, 7 or 8 carbonsin a
`linear or branched arrangement, such that C1-galkyl specifically includes methyl,
`
`ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, tert-butyl, pentyl, hexyl, heptyl and
`octyl. Likewise, Co, as in Coalkyl is defined to identify the presence of a direct
`covalent bond. A group which is designated as being independently substituted with
`substituents may be independently substituted with multiple numbers of such
`substituents. The term "heterocycle" as used herein is intended to include 5- or
`6-membered ring systems which are within the following listing: benzimidazolyl,
`benzodioxanyl, benzofuranyl, benzopyrazolyl, benzothiadiazolyl, benzotriazolyl,
`benzothiophenyl, benzoxadiazolyl, benzoxazolyl, carbazolyl, carbolinyl, chromanyl,
`cinnolinyl, furanyl, imidazolyl, indolinyl, indolyl, indolazinyl, indazolyl,
`isobenzofuranyl, isoindolyl, isoquinolyl, isothiazolyl, isoxazolyl, naphthyridinyl,
`oxadiazolyl, oxazolyl, pyrazinyl, pytazolyl, pytidopyridinyl, pyridazinyl, pyridyl,
`pyrimidyl, pyrrolyl, quinazolinyl, quinolinyl, quinoxalinyl, tetrazolyl, thiadiazolyl,
`thiazolidinyl, thiazolyl, thienyl, triazolyl, azetidinyl, 1,4-dioxanyl, hexahydroazepinyl,
`piperazinyl, piperidinyl, pyrrolidinyl, morpholinyl, thiomorpholinyl,
`-10-
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`dihydrobenzimidazolyl, dihydrobenzofuranyl, dihydrobenzothiophenyl,
`dihydrobenzoxazolyl, dihydrofuranyl, dihydroimidazolyl, dihydroindolyl,
`dibydroisooxazolyl, dihydroisothiazolyl, dihydrooxadiazolyl, dihydrooxazolyl,
`dihydropyrazinyl, dihydropyrazolyl, dihydropyridinyl, dihydropyrimidinyl,
`dihydropyrrolyl, dihydroquinolinyl, dihydrotetrazolyl, dihydrothiadiazolyl,
`dihydrothiazolyl, dihydrothienyl, dihydrotriazolyl, dihydroazetidinyl,
`methylenedioxybenzoyl, tetrahydrofuranyl, tetrahydroimidazolyl,
`tetrahydroisoquinolinyl, and tetrahydrothieny].
`Exemplifying the invention is the use of the compoundsdisclosed in
`the Examples and herein.
`Specific compounds within the present invention include a compound
`which selected from the group consisting of the compoundsdisclosed in the following
`Examples and pharmaceutically acceptable salts thereof and individual diastereomers
`thereof.
`
`The subject compoundsare useful in a methodof inhibiting the
`dipeptidyl peptidase-IV enzymein a patient such as a mammalin need of such
`inhibition comprising the administration of an effective amount of the compound.
`The present invention is directed to the use of the compoundsdisclosed herein as
`inhibitors of dipeptidyl peptidase-IV enzymeactivity.
`In addition to primates, such as humans,a variety of other mammals
`can be treated according to the method of the present invention. For instance,
`mammals including, but not limited to, cows, sheep, goats, horses, dogs, cats, guinea
`pigs, rats or other bovine, ovine, equine, canine, feline, rodent or murine species can
`be treated. However, the method can also be practiced in other species, such as avian
`species (e.g., chickens).
`The present invention is further directed to a methodfor the
`manufacture of a medicamentfor inhibiting dipeptidyl peptidase-[TV enzymeactivity
`in humans and animals comprising combining a compoundof the present invention
`with a pharmaceutical carrier or diluent.
`The subject treated in the present methods is generally a mammal,
`preferably a human being, male or female, in whom inhibition of dipeptidyl peptidase-
`IV enzymeactivity is desired. The term "therapeutically effective amount" meansthe
`amountof the subject compoundthatwill elicit the biological or medical response of
`a tissue, system, animal or humanthat is being sought by the researcher, veterinarian,
`medical doctor or other clinician.
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`The term "composition" as used herein is intended to encompass a
`product comprising the specified ingredients in the specified amounts, as well as any
`product which results, directly or indirectly, from combination of the specified
`ingredients in the specified amounts. Such term in relation to pharmaceutical
`composition, is intended to encompass a product comprising the active ingredient(s),
`andthe inert ingredient(s) that make up the carrier, as well as any product which
`results, directly or indirectly, from combination, complexation or aggregation of any
`two or more of the ingredients, or from dissociation of one or more of the ingredients,
`or from other types of reactions or interactions of one or more ofthe ingredients.
`Accordingly, the pharmaceutical compositions of the present invention encompass
`any composition made by admixing a compoundofthe present invention and a
`pharmaceutically acceptable carrier. By “pharmaceutically acceptable" it is meant the
`carrier, diluent or excipient must be compatible with the other ingredients of the
`formulation and notdeleterious to the recipient thereof.
`The terms "administration of" and or "administering a" compound
`should be understood to mean providing a compoundofthe invention or a prodrug of
`a compoundofthe invention to the individual in need of treatment.
`Theutility of the compounds in accordance with the present invention
`as inhibitors of dipeptidyl peptidase-[V enzymeactivity may be demonstrated by
`methodology knownin the art. Inhibition constants are determined as follows. A
`continuous fluorometric assay is employed with the substrate Gly-Pro-AMC,whichis
`cleaved by DP-IV to release the fluorescent AMC leaving group. The kinetic
`parameters that describe this reaction are as follows: Ky = 50 UM; Keat = 75 si:
`Kea/Km = 1.5x 10°M"s". A typical reaction contains approximately 50 pM enzyme,
`50 uM Gly-Pro-AMC,and buffer (100 mM HEPES, pH 7.5, 0.1 mg/ml BSA)in a
`total reaction volume of 100 wl. Liberation of AMC is monitored continuously in a
`96-well plate fluorometer using an excitation wavelength of 360 nm and an emission
`wavelength of 460 nm. Under these conditions, approximately 0.8 uM AMCis
`produced in 30 minutes at 25 degrees C. The enzymeused in these studies was
`soluble (transmembrane domain and cytoplasmic extension excluded) humanprotein
`producedin a baculovirus expression system (Bac-To-Bac, Gibco BRL). The kinetic
`constants for hydrolysis of Gly-Pro-AMC and GLP-1 were foundto be in accord with
`literature values for the native enzyme. To measure the dissociation constants for
`compounds,solutions of inhibitor in DMSO were added to reactions containing
`enzyme andsubstrate (final DMSO concentration is 1%). All experiments were
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`conducted at room temperature using the standard reaction conditions described
`above. To determine the dissociation constants (Kj), reaction rates were fit by non-
`linear regression to the Michaelis-Menton equation for competitive inhibition. The
`errors in reproducing the dissociation constants are typically less than two-fold.
`In particular, the compoundsof the following examples hadactivity in
`inhibiting the dipeptidyl peptidase-IV enzyme in the aforementioned assays, generally
`with an IC50 of less than about 1 uM. Sucha result is indicative of the intrinsic
`
`activity of the compoundsin use as inhibitors the dipeptidyl peptidase-IV enzyme
`activity.
`
`Dipeptidyl peptidase-[IV enzyme (DP-IV)is a cell surface protein that
`has been implicated in a wide range of biological functions. Jt has a broad tissue
`distribution (intestine, kidney, liver, pancreas, placenta, thymus, spleen, epithelial
`cells, vascular endothelium, lymphoid and myeloid cells, serum), and distinct tissue
`and cell-type expression levels. DP-IV is identical to the T cell activation marker
`CD26, and it can cleave a numberof immunoregulatory, endocrine, and neurological
`peptides in vitro. This has suggested a potential role for this peptidase in a variety of
`disease processes in humansorother species.
`Accordingly, the subject compoundsare useful in a methodfor the
`prevention or treatment of the following diseases, disorders and conditions.
`
`Type II Diabetes and Related Disorders: It is well established that the incretins GLP-1
`and GIP are rapidly inactivated in vivo by DP-IV. Studies with DP-IV’?-deficient
`mice and preliminary clinical trials indicate that DP-IV inhibition increases the steady
`state concentrations of GLP-1 and GIP, resulting in improved glucose tolerance. By
`analogy to GLP-1 and GIP,it is likely that other glucagon family peptides involved in
`glucose regulation are also inactivated by DP-IV (eg. PACAP, glucagon).
`Inactivation of these peptides by DP-IV mayalso play a role in glucose homeostasis.
`The DP-IV inhibitors of the present invention therefore have utility in
`the treatment of type I diabetes and in the treatment and prevention of the numerous
`conditions that often accompany TypeII diabetes, including metabolic syndrome X,
`reactive hypoglycemia, and diabetic dyslipidemia. Obesity, discussed below, is
`another condition that is often found with Type II diabetes that may respond to
`treatment with the compoundsof this invention.
`The following diseases, disorders and conditions are related to Type 2
`diabetes, and therefore may be treated, controlled or in some cases prevented, by
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`treatment with the compoundsof this invention: (1) hyperglycemia, (2) low glucose
`tolerance, (3) insulin resistance, (4) obesity, (5) lipid disorders, (6) dyslipidemia,
`(7) hyperlipidemia, (8) hypertriglyceridemia, (9) hypercholesterolemia,
`(10) low
`HDLlevels, (11) high LDL levels, (12) atherosclerosis and its sequelae, (13)
`vascular restenosis, (14) irritable bowel syndrome, (15) inflammatory boweldisease,
`including Crohn’s disease and ulcerative colitis, (16) other inflammatory conditions,
`(17) pancreatitis, (18) abdominal obesity, (19) neurodegenerative disease, (20)
`retinopathy, (21) nephropathy, (22) neuropathy, (23) Syndrome X, (24) ovarian
`hyperandrogenism (polycystic ovarian syndrome), and other disorders where insulin
`resistance is a component.
`
`Obesity: DP-IV inhibitors may be useful for the treatment of obesity. This is based
`on the observed inhibitory effects on food intake and gastric emptying of GLP-1 and
`GLP-2. Exogenous administration of GLP-1 in humanssignificantly decreases food
`intake and slows gastric emptying (Am.J. Physiol. 277, R910-R916 (1999)). ICV
`administration of GLP-1 in rats and mice also has profound effects on food intake
`(Nature Medicine 2, 1254-1258 (1996)). This inhibition of feeding is not observed in
`GLP-1R‘””mice, indicating that these effects are mediated through brain GLP-1
`receptors. By analogy to GLP-1, it is likely that GLP-2 is also regulated by DP-IV.
`ICV administration of GLP-2 also inhibits food intake, analogousto the effects
`observed with GLP-1 (Nature Medicine 6, 802-807 (2000)).
`
`Growth Hormone Deficiency: DP-IV inhibition may be useful for the treatment of
`growth hormone deficiency, based on the hypothesis that growth-hormonereleasing
`factor (GRF), a peptide that stimulates release of growth hormone from the anterior
`pituitary, is cleaved by the DP-IV enzymein vivo (WO 00/56297). The following
`data provide evidence that GRF is an endogenous substrate:
`(1) GRF is efficiently
`cleaved in vitro to generate the inactive product GRF[3-44] (BBA 1122, 147-153
`(1992));
`(2) GRF is rapidly degraded in plasma to GRF[3-44]; this is prevented by
`the DP-IV inhibitor diprotin A; and (3) GRF[3-44] is f