US007964607B2

(12) United States Patent (10) Patent No.: US 7.964,607 B2 Verhoest et al. (45) Date of Patent: Jun. 21, 2011

(54) PYRAZOLO3,4-DIPYRIMIDINE FOREIGN PATENT DOCUMENTS COMPOUNDS EP 1460.077 9, 2004 WO 02085904 10, 2002 (75) Inventors: Patrick Robert Verhoest, Old Lyme, CT WO 2004037176 5, 2004 (US); Caroline Proulx-Lafrance, Ledyard, CT (US) OTHER PUBLICATIONS Wunder et al., Mol. Pharmacol., vol. 28, No. 6, (2005), pp. 1776 (73) Assignee: Pfizer Inc., New York, NY (US) 1781. van der Staay et al., Neuropharmacology, vol. 55 (2008), pp. 908 (*) Notice: Subject to any disclaimer, the term of this 918. patent is extended or adjusted under 35 U.S.C. 154(b) by 562 days. Primary Examiner — Susanna Moore (74) Attorney, Agent, or Firm — Jennifer A. Kispert; (21) Appl. No.: 12/118,062 Michael Herman (22) Filed: May 9, 2008 (57) ABSTRACT (65) Prior Publication Data The invention provides PDE9-inhibiting compounds of For US 2009/OO3OOO3 A1 Jan. 29, 2009 mula (I), Related U.S. Application Data (I) O (60) Provisional application No. 60/917.333, filed on May R 11, 2007. H N N N (51) Int. Cl. R3 N CO7D 487/04 (2006.01) WS M A 6LX3/59 (2006.01) s' N N A61 P 25/28 (2006.01) R N (52) U.S. Cl...... 514/262.1; 54.4/262 / (58) Field of Classification Search ...... 544/262: R 51.4/262.1 See application file for complete search history. and pharmaceutically acceptable salts thereof, wherein R. R. (56) References Cited RandR areas defined herein. Pharmaceutical compositions containing the compounds of Formula I, and uses thereof in U.S. PATENT DOCUMENTS treating neurodegenerative and cognitive disorders, such as 2003. O139427 A1 7/2003 Castelhano et al...... 514,2611 Alzheimer's disease and Schizophrenia, are also provided. 2004/0176361 A1 9/2004 Fujio et al...... 514,224.2 2004/0259870 Al 12/2004 Feng et al...... 514,229.2 13 Claims, No Drawings US 7,964,607 B2 1. 2 PYRAZOLO3,4-DIPYRIMIDINE 47:1081-1092 (2004). Inhibition of PDE9 has been shown to COMPOUNDS increase LTP. Hendrix, BMC Pharmacol., 5(Supp. 1):55 (2005). RELATED APPLICATION Accordingly, there is a need for PDE9 inhibitors that are effective in treating conditions that may be regulated or nor This application claims the benefit under 35 U.S.C. S 119 malized by inhibition of PDE9. (e) of U.S. provisional application Ser. No. 60/917.333, filed May 11, 2007. SUMMARY OF THE INVENTION FIELD OF THE INVENTION 10 The present invention is directed to compounds of Formula (I), This invention relates to a series of novel compounds that are selective inhibitors of phosphodiesterase type 9 (“PDE9). More particularly, the invention relates to pyra (I) Zolo3,4-dipyrimidinone compounds for use in the treatment 15 O R and prevention of neurodegenerative diseases and other dis H eases and disorders influenced by modulation of PDE9. n N N BACKGROUND OF THE INVENTION R3 WSls M N s N N Cyclic nucleotides cyclic guanosine monophosphate R N (cGMP) and cyclic adenosine monophosphate (cAMP) are / important second messengers and thus are central to the con R trol and regulation of a multitude of cellular events, both physiological and pathophysiological, in a wide variety of 25 Organs. and pharmaceutically acceptable salts thereof, wherein R. R. Cyclic GMP is formed from GTP by the catalytic reaction R, and R are as defined herein. of guanylyl cyclase (GC), which is activated by nitric oxide The present invention is also directed to compositions con (NO). Cyclic GMP in turn activates cGMP-dependent protein taining a compound of Formula (I), or a pharmaceutically kinases (cGK), which mediate localized and global signaling. 30 acceptable salt thereof, and a pharmaceutically acceptable A variety of physiological processes in the cardiovascular, vehicle, carrier or diluent, and optionally further comprising nervous and immune systems are controlled by the a second pharmaceutical agent. NO/cGMP pathway, including ion channel conductance, gly The present invention is further directed to a method of cogenolysis, cellular apoptosis, and Smooth muscle relax inhibiting PDE9 in a mammal in need of such inhibition, ation. In blood vessels, relaxation of vascular Smooth muscles 35 comprising the step of administering to the mammala PDE9 leads to vasodilation and increased blood flow. inhibiting amount of a) a compound of Formula I, or a phar The phosphodiesterase (PDE) enzyme family hydrolyses maceutically acceptable salt thereof, or b) a pharmaceutical cGMP and cAMP. The PDE9 enzyme has been identified as a composition comprising a compound of Formula I, or a phar novel member of the PDE enzyme family that selectively maceutically acceptable salt thereof, and a pharmaceutically hydrolyses cGMP over cAMP. See Fisher et al., J. Biol. 40 Chem., 273 (25), 15559-15564 (1998). PDE9 has been found acceptable vehicle, carrier or diluent. to be present in a variety of human tissues, namely the testes, The present invention is further directed to a method of brain, Small intestine, skeletal muscle, heart, lung, thymus treating a neurodegenerative disease in a mammal in need of and spleen, as well as in Smooth muscle cells within the Such treatment, comprising the step of administering to the human vasculature of a variety of tissues. 45 mammalatherapeutically effective amount of a compound of Recent studies have directly implicated dysfunction of Formula I, or a pharmaceutically acceptable salt thereof. NO/cGMP/cGK signaling in Alzheimer's disease. For The present invention is further directed to a method of example, disruption of Long Term Potentiation (LTP), a promoting neurorestoration in a mammal in need of Such physiological correlate of learning and memory, by amy neurorestoration, comprising the step of administering to the loid-fi peptide was shown to result from a malfunction of 50 mammalatherapeutically effective amount of a compound of NO/cGMP signaling. Puzzo et al., J. Neurosci., 25(29):6887 Formula I, or a pharmaceutically acceptable salt thereof. 6897 (2005). Moreover, in rats showing deficits in memory The present invention is still further directed to a method of tasks due to depletion in forebrain acetylcholinesterase improving cognitive deficits and treating cognitive impair (which is associated with Alzheimer's disease), administra ment in a mammal in need of such improvement or treatment, tion of a nitric oxide mimetic increased GC activity and 55 comprising the step of administering to the mammal athera reversed the cognitive deficits in memory tasks. Bennett et al., peutically effective amount of a compound of Formula I, or a Neuropsychopharmacology, 32:505-513 (2007). It is there pharmaceutically acceptable salt thereof. fore believed that therapeutic agents capable of enhancing the With the foregoing and other advantages and features of the GC/NO/cGMP/cGK signaling cascade may be useful as a invention that will become hereinafter apparent, the nature of new approach to the treatment of Alzheimer's disease and 60 the invention may be more clearly understood by reference to other neurodegenerative disorders. the following detailed description of the invention and the By reducing or preventing the hydrolysis of c(GMP by appended claims. PDE9, PDE9 inhibitors elevate the intracellular level of cGMP, thus enhancing or prolonging its effects. It has been DETAILED DESCRIPTION OF THE INVENTION found that an increase incGMP concentration in rats leads to 65 improvement in learning and memory in Social and object The present invention comprises novel selective PDE9 recognition tests. See, e.g., Boess et al., Neuropharmacology, inhibitors of Formula (I),

US 7,964,607 B2 15 16 The term “aryl' is also intended to include the partially hydro 3-bipyrazinyl), pyridopyridinyl, pyrrolopyrazolyl, dihydro genated derivatives of Such ring systems, e.g. 1.2.3,4-tetrahy pyrrolopyrazolyl (e.g. dihydropyrrolo 1.2-bipyrazolyl), dronaphthyl. quinazolinyl (also known as “1,3-benzodiazinyl'), quinolinyl The term “aryloxy' denotes an aryl radical bonded to an (also known as "1-benzazinyl), isoquinolinyl (also known as oxygen atom that is attached to a core structure. Such as 5 “2-benzazinyl'), quinolizinyl, quinolyl, isoquinolyl, quinox benzyloxy. alinyl, dithianaphthalenyl, thienofuranyl (e.g. thieno3.2-b The term "cycloalkyl denotes a saturated monocyclic or furanyl), and the like. bicyclic cycloalkyl group. Examples of cycloalkyl groups Examples of 3-fused ring heteroaryls include acridinyl, include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, diazaanthryl, triaZaphenanthrene, carbazolyl, carbolinyl, cycloheptyl, cyclooctyl, and the like. 10 furocinnolinyl, perimidinyl, phenanthridinyl, phenanthroli The term “halogen' or “halo represents chlorine, bro nyl, phenazinyl, phenothiazinyl, phenoxathiinyl, phenoxazi mine, fluorine and iodine atoms and radicals. The term “haloalkyl refers to an alkyl or cycloalkyl sub nyl, thianthrenyl, Xanthenyl, and the like. stituent wherein at least one hydrogen radical is replaced with The term "heterocycloalkyl denotes a saturated monocy a halogen radical. Where more than one hydrogen is replaced 15 clic or polycyclic cycloalkyl group, in which at least one of with halogen, the halogens may be the same or different. the carbon atoms is replaced with a heteroatom such as nitro Examples of haloalkyl radicals include trifluoromethyl, 2.2, gen, oxygen or Sulfur. If the heterocycle contains more than 2-trifluoroethyl, 4.4,4-trifluorobutyl, 4.4-difluorocyclohexyl, one heteroatom, the heteroatoms may be the same or differ chloromethyl, dichloromethyl, trichloromethyl, 1-bromoet ent. The heterocycloalkyl radicals may be bonded via a car hyl, and the like. bon atom or a heteroatom. Examples of heterocycloalkyl The term “haloalkoxy” refers to an alkoxy radical in which groups include aZetidinyl, dioxacyclohexyl, 1,3-dioxolanyl. at least one hydrogen radical is replaced with a halogen radi imidazolidinyl, morpholinyl, piperazinyl, piperidinyl, pyra cal. Where more than one hydrogen is replaced with halogen, Zolidinyl, pyrrolidinyl, tetrahydrofuranyl, tetrahydropyranyl. the halogens may be the same or different. Examples of tetrahydrothiopyranyl, thiazanyl, and the like. haloalkoxy radicals include difluoromethoxy, trifluo 25 A cyclic group may be bonded to another group in more romethoxy, 2.2.2-trifluoroethoxy, chloromethoxy, bro than one way. If no particular bonding arrangement is speci momethoxy, and the like. fied, then all possible arrangements are intended. For The term "heteroarylas used herein includes heterocyclic example, the term "pyridyl includes 2-, 3- or 4-pyridyl (2-, unsaturated ring systems containing one or more heteroatoms 3-, or 4-pyridinyl). Such as nitrogen, oxygen, and Sulfur. If the heteroaryl group 30 The term “mammal’ means animals including, for contains more than one heteroatom, the heteroatoms may be example, dogs, cats, cows, sheep, goats, horses and humans. the same or different. The heteroaryl radicals may be bonded Preferred mammals include humans. via a carbon atom or a heteroatom. The term "heteroaryl' is The term “oxo' means a carbonyl group formed by the also intended to include the partially hydrogenated deriva combination of a carbon atom and an oxygen atom. tives of Such ring systems. Examples of heteroaryl groups 35 The term “patient' includes both human and non-human include furanyl (also known as “furyl'), imidazolinyl, imida patients. Zolyl (also known as “1,3-diazolyl), indolyl, oxadiazolyl, The phrase “pharmaceutically acceptable' indicates that oxazinyl, oxazolyl, isoxazolyl pyranyl, pyrazinyl (also the designated carrier, vehicle, diluent, and/or salt is generally known as “1,4-diazinyl), pyrazolyl (also known as “1,2- chemically and/or physically compatible with the otheringre diazolyl), pyrazolinyl, pyrazyl, pyridazinyl (also known as 40 dients comprising the formulation, and physiologically com “1,2-diazinyl'), pyridyl (also known as pyridinyl), pyrimidi patible with the recipient thereof. nyl (also known as “1,3 diazinyl' and “pyrimidyl'), pyrrolyl, The term “salts' refers to both organic and inorganic salts thiadiazinyl, thiadiazolyl, thiatriazolyl, thiazolyl, isothiaz of a compound of Formula (I). Such salts can be prepared in olyl, thienyl, thiofuranyl (also known as “thiophenyl), thi situ during the final isolation and purification of a compound, opyranyl, triazinyl, triazolyl, and the like. 45 or by separately reacting a compound, prodrug or stereoiso The term "heteroaryl also embraces radicals in which 2 or mer of Formula (I) with a suitable organic or inorganic acid or 3 rings are fused together, wherein at least on Such ring base and isolating the salt thus formed. Representative contains a heteroatom as a ring atom, including radicals anionic salts include hydrobromide, hydrochloride, hydroio wherein (a) a heterocycloalkyl ring is fused with an aryl or dide, Sulfate, bisulfate, nitrate, acetate, trifluoroacetate, heteroaryl ring, or (b) a cycloalkyl ring is fused with a het 50 oxalate, besylate, palmitate, pamoate, malonate, Stearate, lau eroaryl ring. Examples of 2-fused ring heteroaryls include rate, malate, borate, benzoate, lactate, phosphate, hexafluo benzodioxinyl, dihydrobenzodioxinyl, benzofuranyl, dihy rophosphate, benzene Sulfonate, tosylate, formate, citrate, drobenzofuranyl, isobenzofuranyl, benzimidazolyl, ben maleate, fumarate. Succinate, tartrate, naphthylate, mesylate, Zothiadiazolyl, tetrahydrobenzothiadiazolyl, benzothiazolyl, glucoheptonate, lactobionate and laurylsulphonate salts and benzothienyl (also known as “benzothiophenyl.” “thionaph 55 the like. Representative cationic salts include Sodium, potas thenyl, and “benzothiofuranyl), benzoxazinyl, dihydroben sium, calcium, and magnesium salts and the like. See gener Zoxazinyl, benzoxazolyl, chromanyl, isochromanyl, chrome ally, e.g., Berge, et al., J. Pharm. Sci., 66, 1-19 (1977). nyl, cinnolinyl (also known as “1,2-benzodiazinyl), A salt of a compound of Formula (I) may be readily pre imidazopyridinyl (e.g. imidazol-2-alpyridinyl orimidazo4. pared by mixing together Solutions of a compound of Formula 5-cpyridinyl), indazolyl, indolinyl, isoindolinyl, indolizinyl, 60 (I) and the desired acid or base, as appropriate. The salt may indolyl, isoindolyl, naphthyridinyl, Oxathiolopyrrolyl, pte precipitate from solution and be collected by filtration or may ridinyl, pthalazinyl, purinyl (also known as “imidazo[4,5-d be recovered by evaporation of the solvent. pyrimidinyl), pyranopyrrolyl pyrazoloazepinyl, tetrahydro The term “radical denotes a group of atoms that behaves pyrazoloazepinyl (e.g. tetrahydropyrazolo 1.5-aaZepinyl), as a single reactant in a chemical reaction, e.g., an organic pyrazolopyridinyl, tetrahydropyrazolopyridinyl (e.g. tetrahy 65 radical is a group of atoms that imparts characteristic prop dropyrazolo 1.5-alpyridinyl), pyrazolopyrimidinyl (e.g. erties to a compound containing it, or which remains pyrazolo 3,4-dipyrimidinyl), pyridopyrazinyl (e.g. pyrido2. unchanged during a series of reactions or transformations. US 7,964,607 B2 17 18 The symbol ' ' represents a covalent bond. metabolism or hydrolysis) during its residence time in the The phrase “reaction-inert solvent' or “inert solvent' body. A discussion of the preparation and use of prodrugs is refers to a solvent, or mixture of solvents, that does not provided by Higuchi & Stella, “Prodrugs as Novel Delivery interact with starting materials, reagents, intermediates or Systems”, Vol. 14 of the A.C.S. Symposium Series, and in products in a manner that adversely affects their desired prop “Bioreversible Carriers in Drug Design, ed. Edward B. erties. Roche, American Pharmaceutical Association and Pergamon The terms “treat,” “treating,” “treated” or “treatment” as Press, 1987. All prodrugs of the various compounds of For used herein includes preventative (e.g., prophylactic), pallia mula (I) are within the scope of the present invention. tive or curative uses or results. The present invention also embraces isotopically-labeled 10 compounds of Formula (I) that are identical to those recited The compounds of Formula (I) may contain asymmetric or herein, but for the fact that one or more atoms are replaced by chiral centers and, therefore, exist in different stereoisomeric an atom having an atomic mass or mass number different forms. Those skilled in the art will appreciate that, unless from the atomic mass or mass number usually found in otherwise specified, all stereoisomers (e.g., enantiomers and nature. Examples of isotopes that can be incorporated into diastereoisomers, and racemic mixtures thereof) of the novel 15 compounds of Formula (I) include isotopes of hydrogen, compounds and intermediates described, illustrated and/or carbon, nitrogen, oxygen, phosphorus, fluorine, and chlorine, discussed herein are within the scope of the claimed inven Such as 2H, *H, 13C, 14C, 15N, 18O, 17O, 3P. 32P 35S, F and tion. In addition, unless otherwise specified, the present Cl, respectively. The compounds of Formula (I), and phar invention embraces all geometric and positional isomers. The maceutically acceptable salts thereof, that contain the afore (3S4S) enantiomer of the core pyrrolidinyl configuration is mentioned isotopes and/or other isotopes of the other atoms preferred. are within the scope of the instant invention. Diasteriomeric mixtures can be separated into their indi Certain isotopically-labeled compounds of Formula (I), for vidual diastereomers on the basis of their physical chemical example those into which radioactive isotopes such as Hand differences by methods well-known to those of ordinary skill Care incorporated, are useful in drug and/or substrate tissue in the art, Such as by chromatography and/or fractional crys 25 distribution assays. Tritiated, i.e., H and C, isotopes are tallization. Enantiomers can be separated by converting the particularly preferred for their ease of preparation and detect enantiomeric mixture into a diasteriomeric mixture by reac ability. Furthermore, substitution with heavier isotopes such tion with an appropriate optically active compound (e.g., as deuterium, i.e., H. may afford certain therapeutic advan alcohol), separating the diastereomers and converting (e.g., tages resulting from greater metabolic stability, for example, hydrolyzing) the individual diastereomers to the correspond 30 increased in vivo half-life, or reduced dosage requirements ing pure enantiomers. Additional methods include resolution and, hence, may be preferred in some circumstances. Isoto of racemic mixtures using chiral salts, as well as chiral chro pically-labeled compounds of Formula (I), and pharmaceuti matography. cally acceptable salts thereof, can be generally prepared by Those skilled in the art will further recognize that the carrying out analogous procedures to those disclosed in the compounds of Formula (I) can exist in crystalline form as 35 Schemes and/or in the Examples below, by substituting a hydrates wherein molecules of water are incorporated within readily available isotopically-labeled reagent for a non-iso the crystal structure thereof and as solvates wherein mol topically labeled reagent. ecules of a solvent are incorporated therein. All such hydrate The invention also includes pharmaceutical compositions and Solvate forms are considered part of this invention. comprising an amount of a compound of Formula (I), or a Practitioners will appreciate that certain compounds of 40 pharmaceutically acceptable salt of the compound, and Formula (I) may exist as tautomeric isomers, i.e., that equi optionally a pharmaceutically acceptable vehicle, carrier or librium exists between two isomers which are in rapid equi diluent. In a preferred embodiment, the pharmaceutical com librium with each other. A common example of tautomerism position is of an amount effective at inhibiting the enzyme is keto-enol tautomerism, i.e., PDE9 in a mammal. In another preferred embodiment, the 45 mammal is a human. The present invention includes the use of a combination of a PDE9 inhibitor compound as provided in Formula (I) and one or more additional pharmaceutically active agent(s). If a combination of active agents is administered, then they may s be administered sequentially or simultaneously, in separate dosage forms or combined in a single dosage form. Accord -O ingly, the present invention also includes pharmaceutical O H compositions comprising an amount of: (a) a first agent com prising a compound of Formula (I) or a pharmaceutically The degree to which one tautomer is present over the other 55 acceptable salt of the compound; (b) a second pharmaceuti depends upon various factors, including Substitution pattern cally active agent; and (c) a pharmaceutically acceptable car and solvent type. Other examples in accordance with the rier, vehicle or diluent. present invention will be recognized by those skilled in the Various pharmaceutically active agents may be selected for art. All tautomeric forms of Formula (I) are included within use in conjunction with the compounds of Formula (I), the scope of the invention unless otherwise specified. 60 depending on the disease, disorder, or condition to be treated. The present invention also includes prodrugs of the com Pharmaceutically active agents that may be used in combina pounds of the invention. The term “prodrug” refers to a drug tion with the compositions of the present invention include, precursor which, following administration, releases the drug without limitation: in vivo via a chemical or physiological process (e.g., upon (i) acetylcholinesterase inhibitors, such as donepezil being brought to physiological pH or through enzymatic 65 hydrochloride (E2020, ARICEPT, MEMAC), physostigmine activity). The prodrug may itself be biologically active, or salicylate (ANTILIRIUM), physostigmine sulfate (ES may be converted to a biologically active compound (e.g. by ERINE), metrifonate, neostigmine, pyridostigmine (MESTI US 7,964,607 B2 19 20 NON), ambenonium (MYTELASE), demarcarium, tolterodine (DETROL), oxybutynin (DITROPAN, LYRINEL Debio992 (also known as ZT-1), rivastigmine (EXELON). XL, OXYTROL), penthienate bromide, propantheline (PRO ladostigil (also known as TV3326), NP-0361, galantamine BANTHINE), cyclizine, imipramine hydrochloride (TOF hydrobromide (RAZADYNE, RIMINYL, NIVALIN), RANIL), imipramine maleate (SURMONTIL), lofepramine, tacrine (COGNEX), Velnacrine maleate, memoquin, desipramine (NORPRAMIN), doxepin (SINEQUAN, huperzine A (HUP-A), phenserine, and edrophonium (EN ZONALON), trimipramine (SURMONTIL), and glycopyr LON, TENSILON); rolate (ROBINUL): (ii) amyloid-fi (or fragments thereof). Such as ABs con (viii) anticonvulsants, such as carbamazepine (TEGRE jugated to pan HLA DR-binding epitope (PADRE), ACC TOL, CARBATROL), oxcarbazepine (TRILEPTAL), pheny 001, ACI-01, ACI-24, AN-1792, Affitope AD-01, CAD106, 10 toin sodium (PHENYTEK), fosphenytoin (CEREBYX, and V-950: PRODILANTIN), divalproex sodium (DEPAKOTE), gabap (iii) antibodies to amyloid-3 (or fragments thereof). Such as entin (NEURONTIN), pregabalin (LYRICA), topirimate bapineuzumab (also known as AAB-001), AAB-002, ACI (TOPAMAX), valproic acid (DEPAKENE), valproate 01-Ab7, BAN-2401, intravenous Ig (GAMMAGARD), sodium (DEPACON), 1-benzyl-5-bromouracil, progabide, LY2062430 (humanized m266), PF-04360365 (also known 15 beclamide, and primidone (MYSOLINE): as RN-1219), RN-6G, R-1450, ACU-5A5, huC091, and those (ix) antipsychotics, such as lurasidone (also known as disclosed in International Patent Publication Nos WOO4/ SM-13496), aripiprazole (ABILIFY), chlorpromazine 032868, WO05/025616, WO06/036291, WO06/069081, (THORAZINE), haloperidol (HALDOL), flupentixol WO06/118959, in US Patent Publication Nos US2003/ decanoate (DEPIXOL, FLUANXOL), reserpine (SER 0073655, US2004/0192898, US2005/0048049, US2005/ PLAN), pimozide (ORAP), fluphenazine decanoate, 0.019328, in European Patent Publication Nos EP0994728 fluphenazine hydrochloride, prochlorperazine (COMPRO). and 1257584, and in U.S. Pat. No. 5,750,349; asenapine, loxapine (LOXITANE), mesoridazine, molindone (iv) amyloid-lowering or -inhibiting agents (including (MOBAN), perphenazine, thioridazine, thiothixine, trifluop those that reduce amyloid accumulation and fibrillization) erazine (STELAZINE), clozapine (CLOZARIL), norclozap Such as bisnorcymserine (also known as BNC), pioglitaZone, 25 ine (ACP-104), risperidone (RISPERDAL), paliperidone PBT2, flurbiprofen (ANSAID, FROBEN) and its R-enanti (INVEGA), melperone, olanzapine (ZYPREXA), quetiapine omer tarenflurbil (also known as MPC-7869; FLURIZAN), (SEROQUEL), sertindole, sulpiride (MERESA, DOG nitroflurbiprofen, fenoprofen (FENOPRON, NALFON), ibu MATYL, SULPITIL), amisulpride, ziprasidone (GEODON), profen (ADVIL, MOTRIN, NUROFEN), ibuprofen lysinate, blonanserin (LONASEN), and bifeprunox; meclofenamic acid, meclofenamate sodium (MECLOMEN), 30 (x) calcium channel blockers such as nilvadipine (ESCOR, indomethacin (INDOCIN), diclofenac Sodium NIVADIL), amlodipine (NORVASC, ISTIN, AMLODIN), (VOLTAREN), diclofenac potassium, Sulindac (CLINO felodipine (PLENDIL), nicardipine (CARDENE), nifedipine RIL), Sulindac sulfide, diflunisal (DOLOBID), naproxen (ADALAT, PROCARDIA), MEM 1003 and its parent com (NAPROSYN), naproxen sodium (ANAPROX, ALEVE), pound nimodipine (NIMOTOP), nisoldipine (SULAR), insulin-degrading enzyme (also known as insulysin), the 35 nitrendipine, lacidipine (LACIPIL, MOTENS), lercanidipine gingko biloba extract EGb-761 (ROKAN, TEBONIN), tra (ZANIDIP), diltiazem (CARDIZEM), verapamil (CALAN, miprosate (NC-758, CEREBRIL, ALZHEMED), eprodisate VERELAN), and enecadin (also known as NS-7); (NC-503, FIBRILLEX, KIACTA), compound W (3,5-bis(4- (xi) catechol O-methyltransferase (COMT) inhibitors, nitrophenoxy)benzoic acid), NGX-96992, neprilysin (also such as tolcapone (TASMAR), entacapone (COMTAN), and known as neutral endopeptidase (NEP)), scyllo-inositol (also 40 tropolone; known as scyllitol, ELND005, AZD-103), atorvastatin (LIPI (xii) central nervous system stimulants, such as caffeine, TOR), simvastatin (ZOCOR), KLVFF-(EEX)3, and RAGE phenmetrazine, phendimetrazine, pemoline, fencamfamine (receptor for advanced glycation end-products) inhibitors; (GLUCOENERGAN, REACTIVAN), fenethylline (CAP (v) alpha-adrenergic receptor agonists, such as clonidine TAGON), pipradol (MERETRAN), deanol (also known as (CATAPRES), metaraminol (ARAMINE), methyldopa (AL 45 dimethylaminoethanol), methylphenidate (DAYTRANA), DOMET, DOPAMET, NOVOMEDOPA), tizanidine methylphenidate hydrochloride (RITALIN), dexmeth (ZANAFLEX), phenylephrine (also known as neosyneph ylphenidate (FOCALIN), amphetamine (alone or in combi rine), methoxamine, cirazoline, guanfacine (INTUNIV), nation with other CNS stimulants, e.g. ADDERALL (am lofexidine, xylazine, modafinil (PROVIGIL), adrafinil, and phetamine aspartate, amphetamine Sulfate, armodafinil (NUVIGIL); 50 dextroamphetamine Saccharate, and dextroamphetamine Sul (vi) beta-adrenergic receptor blocking agents (beta block fate)), dextroamphetamine sulfate (DEXEDRINE, DEX ers), such as carteolol, esmolol (BREVIBLOC), labetalol TROSTAT), methamphetamine (DESOXYN), lisdexamfe (NORMODYNE, TRANDATE), oxprenolol (LARACOR, tamine (VYVANSE), and benzphetamine (DIDREX): TRASACOR), pindolol (VISKEN), propanolol (IN (xiii) corticosteroids, such as prednisone (STERAPRED, DERAL), sotalol (BETAPACE, SOTALEX, SOTACOR), 55 DELTASONE), prednisolone (PRELONE), predisolone timolol (BLOCADREN, TIMOPTIC), acebutolol (SEC acetate (OMNIPRED, PRED MILD, PRED FORTE), pred TRAL PRENT), nadolol (CORGARD), metoprolol tartrate nisolone sodium phosphate (ORAPRED ODT), methylpred (LOPRESSOR), metoprolol succinate (TOPROL-XL), nisolone (MEDROL); methylprednisolone acetate (DEPO atenolol (TENORMIN), butoxamine, and SR 59230A MEDROL), and methylprednisolone sodium succinate (Sanofi); 60 (A-METHAPRED, SOLU-MEDROL); (vii) anticholinergics, such as amitniptyline (ELAVIL, (xiv) dopamine receptor agonists, such as apomorphine ENDEP), butriptyline, benztropine mesylate (COGENTIN), (APOKYN), bromocriptine (PARLODEL), cabergoline trihexyphenidyl (ARTANE), diphenhydramine (DOSTINEX), dihydrexidine, dihydroergocryptine, (BENADRYL), orphenadrine (NORFLEX), hyoscyamine, fenoldopam (CORLOPAM), lisuride (DOPERGIN), per atropine (ATROPEN), scopolamine (TRANSDERM 65 golide (PERMAX), piribedil (TRIVASTAL, TRASTAL), SCOP), scopolamine methylbromide (PARMINE), dicyclo pramipexole (MIRAPEX), quinpirole, ropinirole (REQUIP), verine (BENTYL, BYCLOMINE, DIBENT DILOMINE, and rotigotine (NEUPRO); US 7,964,607 B2 21 22 (XV) dopamine receptor antagonists, such as tetrabenazine (XXiv) muscarinic receptor (particularly M1 Subtype) ago (NITOMAN, XENAZINE), 7-hydroxyamoxapine, droperi nists, such as bethanechol chloride (DUVOID, URECHO dol (INAPSINE, DRIDOL, DROPLETAN), domperidone LINE), pilocarpine (SALAGEN), NGX267, arecoline, (MOTILIUM), L-741742, L-745870, raclopride, SCH L-687306, L-689660, furtrethonium iodide (FURAMON, 23390, ecopipam, SKF-83566, and metoclopramide FURANOL), furtrethonium benzensulfonate, furtrethonium (REGLAN); p-toluenesulfonate, McN-A-343, oxotremorine, and carba (Xvi) dopamine reuptake inhibitors such as nomifensine chol (CARBASTAT, MIOSTAT, CARBOPTIC); maleate (MERITAL), vanoxerine (also known as GBR (XXV) nicotinic receptor agonists, such as epibatidine, 12909) and its decanoate ester DBL-583, and amineptine; ABT-089, ABT-594, AZD-0328, R4996 (also known as (Xvii) gamma-amino-butyric acid (GABA) receptor ago 10 MEM-63908), TC-5619, and EVP-6124; nists, such as baclofen (LIORESAL, KEMSTRO), pentobar (XXvi) neuroprotective drugs such as 2.3.4.9-tetrahydro bital (NEMBUTAL), progabide (GABRENE), and clom 1H-carbazol-3-one oxime, AL-108, ACD3480 (also known ethiazole; as TC-1734), bis(4-3-D-glucopyranosyloxybenzyl)-2-f-D- (Xviii) immunomodulators such as glatirameracetate (also 15 glucopyranosyl-2-isobutyltartrate (also known as dactylorhin known as copolymer-1; COPAXONE), MBP-8298 (synthetic B or DHB), Xaliproden (XAPRILA), dimeboline hydrochlo myelin basic protein peptide), dimethyl fumarate, fingolimod ride (DIMEBON), disufenton (NXY-059, CEROVIVE), (also known as FTY720), roquinimex (LINOMIDE), lacqui arundic acid (ONO-2506, PROGLIA, CEREACT), citicoline nimod (also known as ABR-215062 and SAIK-MS), ABT (also known as cytidine 5'-diphosphocholine), edaravone 874 (human anti-IL-12 antibody), rituximab (RITUXAN), (RADICUT), AEOL-10150, AGY-94.806 (also known as alemtuzumab (CAMPATH), daclizumab (ZENAPAX), and SA-450 and Msc-1), granulocyte-colony simulating factor natalizumab TSABRI): (AX-200), BAY-387271 (also known as KN-387271), DP (xix) immunosuppressants such as methotrexate (TREX b99, HF-0220 (17-B-hydroxyepiandrosterone), HF-0420 ALL, RHEUMATREX), mitoxantrone (NOVANTRONE), (also known as oligotropin), pyridoxal 5'-phosphate (also mycophenolate mofetil (CELLCEPT), mycophenolate 25 known as MC-1), microplasmin, S-18986, piclozotan (also sodium (MYFORTIC), azathioprine (AZASAN, IMURAN), known as SUN-N4057), NP0311 12, L-seryl-L-methionyl-L- mercaptopurine (PURI-NETHOL), cyclophosphamide alanyl-L-lysyl-L-glutamyl-glycyl-L-valine, and SUN (NEOSAR, CYTOXAN), chlorambucil (LEUKERAN), N8075; cladribine (LEUSTATIN, MYLINAX), alpha-fetoprotein, (XXvii) norepinephrine (noradrenaline) reuptake inhibi etanercept (ENBREL), and 4-benzyloxy-5-((5-undecyl-2H 30 tors, such as atomoxetine (STRATTERA), doxepin pyrrol-2-ylidene)methyl)-2,2'-bi-1H-pyrrole (also known as (APONAL, ADAPIN, SINEQUAN), nortriptyline (AVEN PNU-156804); TYL, PAMELOR, NORTRILEN), amoxapine (ASENDIN, (XX) interferons, including interferon beta-1a (AVONEX, DEMOLOX, MOXIDIL), reboxetine (EDRONAX, VES REBIF) and interferon beta-1b (BETASERON, TRA), viloxazine (VIVALAN), maprotiline (DEPRILEPT, BETAFERON); 35 LUDIOMIL, PSYMION), bupropion (WELLBUTRIN), and (xxi) levodopa (or its methyl or ethyl ester), alone or in radaxafine; combination with a DOPA decarboxylase inhibitor (e.g. car (xxviii) other PDE9 inhibitors, such as BAY 73-6691 and bidopa (SINEMET, CARBILEV. PARCOPA, V1512), those disclosed in US Patent Publication NoS US2003/ benserazide (MADOPAR), C.-methyldopa, monoflurometh 0195205, US2004/0220186, US2006/011 1372, and US2006/ yldopa, difluoromethyldopa, brocresine, or m-hydroxyben 40 0106035: Zylhydrazine); (xxix) other phosphodiesterase (PDE) inhibitors, including (xxii) N-methyl-D-aspartate (NMDA) receptor antago (a) PDE1 inhibitors (e.g. vinpocetine (CAVINTON, CERAC nists, such as memantine (NAMENDA, AXURA, EBIXA), TIN, INTELECTOL) and those disclosed in U.S. Pat. No. amantadine (SYMMETREL), acamprosate (CAMPRAL), 6,235.742), (b) PDE2 inhibitors (e.g. erythro-9-(2-hydroxy besonprodil (also known as PD-196,860 or CI-1041), ket 45 3-nonyl)adenine (EHNA), BAY 60-7550, and those amine (KETALAR), delucemine (also known as NPS 1506), described in U.S. Pat. No. 6,174,884), (c) PDE4 inhibitors dexanabinol (also known as HU-211), dextromethorphan, (e.g. rolipram, Ro 20-1724, ibudilast (KETAS), piclamilast dextrorphan, traxoprodil (also known as CP-101,606), (also known as RP73401), CDP840, cilomilast (ARIFLO), himantane, idantadol (also known as V-3381), lancicemine roflumilast, tofimilast, oglemilast (also known as GRC 3886), (also known as AR-R 15896), levorphanol (DROMORAN), 50 tetomilast (also known as OPC-6535), lirimifast, theophyl methadone, (DOLOPHINE), neramexane (also known as line (UNIPHYL, THEOLAIR), arofylline (also known as MRZ 2/579), perzinfotel, phencyclidine, tianeptine LAS-31025), doxofylline, RPR-122818, or mesembrine), (STABLON), dizocilpine (also known as MK-801), ibogaine, and (d) PDE5 inhibitors (e.g. sildenafil (VIAGRA, REVA voacangine, tiletamine, riluzole (RILUTEK), aptiganel TIO), tadalafil (CIALIS), wardenafil (LEVITRA, (CERESTAT), gavestinel, and remacimide: 55 VIVANZA), udenafil, avanafil, dipyridamole (PERSAN (xxiii) monoamine oxidase (MAO) inhibitors, such as sel TINE), E-4010, E-4021, E-8010, Zaprinast, PF489791, egiline (EMSAM), selegiline hydrochloride (I-deprenyl, UK-357903, DA-8159, and those disclosed in International ELDEPRYL, ZELAPAR), dimethylselegilene, brofaromine, Patent Applications WO05/0496.16, WO06/120552, and phenelzine (NARDIL), tranylcypromine (PARNATE), WO07/122466); moclobemide (AURORIX, MANERIX), befloxatone, safina 60 (XXX) quinolines, such as quinine (including its hydrochlo mide (also known as PNU-151774E), isocarboxazid (MAR ride, dihydrochloride, Sulfate, bisulfate and gluconate salts), PLAN), nialamide (NIAMID), rasageline (AZILECT), ipro chloroquine, hydroxychloroquine (PLAQUENIL), meflo niazide (MARSILID, IPROZID, IPRONID), iproclozide, quine (LARIAM), and amodiaquine (CAMOQUIN, FLA toloxatone (HUMORYL, PERENUM), bifemelane, desox VOQUINE): ypeganine, harmine (also known as telepathine or banaster 65 (xxxi) B-secretase inhibitors, such as WY-25105, (+)- ine), harmaline, linezolid (ZYVOX, ZYVOXID), and par phenserine tartrate (POSIPHEN), LSN-2434074 (also known gyline (EUDATIN, SUPIRDYL); as LY-2434074), PNU-33312, KMI-574, SCH-745966, Ac US 7,964,607 B2 23 24 rER (N-acetyl-D-arginyl-L-arginine), loxistatin (also aphasia), Gerstmann-Stratissler-Scheinker disease, glau known as E64d), and CA074Me: coma, Huntington's disease (chorea), HIV-associated (xxxii)y-secretase inhibitors, such as LY-411.575, LY-685, dementia, hyperkinesias, Kennedy's disease, Korsakoffs 458, ELAN-G, ELAN-Z, 4-chloro-N-2-ethyl-1 (S)-(hy syndrome (amnesic-confabulatory syndrome), Krabbe's dis droxymethyl)butylbenzenesulfon-amide: ease, Lewy body dementia, logopenic progressive aphasia, (xxxiii) serotonin (5-hydroxytryptamine) 1A (5-HT) Machado-Joseph disease (spinocerebellar ataxia type 3). receptor antagonists. Such as spiperone, levo-pindolol, BMY multiple Sclerosis, multiple system atrophy (olivopontocer 7378, NAD-299, S(-)-UH-301, NAN 190, WAY 100635, ebellaratrophy), myasthenia gravis, Parkinson's disease, Pel lecozotan (also known as SRA-333): izaeus-Merzbacher disease, Pick's disease, pre-senile (xxxiv) serotonin (5-hydroxytryptamine) 6 (5-HT) recep 10 dementia (mild cognitive impairment), primary lateral scle tor antagonists, such as mianserin (TORVOL, BOLVIDON, rosis, primary progressive aphasia, radiation-induced demen NORVAL), methiothepin (also known as metitepine), tia, RefSum's disease (phytanic acid storage disease), Sand ritanserin, ALX-1161, ALX-1175, MS-245, LY-483.518 (also hoff disease, Schilder's disease, Schizophrenia, semantic known as SGS518), MS-245, Ro 04-6790, RO 43-68544, Ro dementia, senile dementia, Shy-Drager syndrome, spinocer 63-0563, RO 65-71.99, Ro 65-7674, SB-399885, SB-214111, 15 ebellar ataxias, spinal muscular atrophies, Steele-Richard SB-258510, SB-271046, SB-357134, SB-699929, son-Olszewski disease (progressive Supranuclear palsy), SB-271046, SB-742457 and PRX-07034; tabes dorsalis, tardive dyskinesia, Vascular amyloidosis, and (XXXV) serotonin (5-HT) reuptake inhibitors such as ala vascular dementia (multi-infarct dementia). proclate, citalopram (CELEXA, CIPRAMIL), escitalopram Preferably the neurodegenerative disease or disorder is (LEXAPRO, CIPRALEX), clomipramine (ANAFRANIL), Alzheimer's disease. duloxetine (CYMBALTA), femoxetine (MALEXIL), fenflu Other conditions and disorders associated with PDE9 that ramine (PONDIMIN), norfenfluramine, fluoxetine may be treated or controlled by the methods of the present (PROZAC), fluvoxamine (LUVOX), indalpine, milnacipran invention include disorders of the urogenital system Such as (IXEL), paroxetine (PAXIL SEROXAT), sertraline sexual dysfunction, attention deficit disorder (ADD), atten (ZOLOFT, LUSTRAL), trazodone (DESYREL, MOLI 25 tion deficit hyperactivity disorder (ADHD), diabetes, cardio PAXIN), venlafaxine (EFFEXOR), Zimelidine (NORMUD, vascular disorders or diseases such as systemic hypertension, ZELMID), bici fadine, desvenlafaxine (PRISTIQ), bra pulmonary hypertension, congestive heart failure, coronary sofensine, and tesofensine; artery disease, atherosclerosis, stroke, thrombosis, conditions (XXXvi) trophic factors, such as nerve growth factor (NGF), of reduced blood vessel patency (e.g. post-percutaneous basic fibroblast growth factor (bFGF), neurotrophin-3 (NT 30 transluminal coronary angioplasty), peripheral vascular dis 3), brain-derived neurotrophic factor (BDNF), and glial-de ease, renal disease, angina (including stable, unstable, and rived neurotrophic factor (GDNF), and agents that stimulate variant (Prinzmetal) angina), and any condition where local production of trophic factors, such as propentofylline, improved blood flow leads to improved end organ function. idebenone, and AIT-082 (NEOTROFIN); and the like. The present invention also relates to methods for promot The invention also includes methods of inhibiting PDE9 in 35 ing neurorestoration and functional recovery in patients Suf a mammal comprising administering to the mammal in need fering from traumatic or non-traumatic injury to the brain, of such inhibition a PDE9 inhibiting amount of: (a) a com spinal cord or peripheral nerves. Traumatic brain injuries pound of Formula (I), or a pharmaceutically acceptable salt include both closed head injuries (in which the skull is not thereof, or (b) a pharmaceutical composition comprising a broken) and open, or penetrating, head injuries (in which an compound of Formula (I), or a pharmaceutically acceptable 40 object pierces the skull and breaches the dura mater), wherein salt thereof, in a pharmaceutically acceptable vehicle, carrier Sudden trauma (e.g., accidents, falls, assaults) causes damage or diluent; either alone or in combination with a second agent to the brain tissue by tearing, stretching, bruising, or Swelling. as described above. Causes of non-traumatic brain injuries include aneurism, The invention also includes methods of treating conditions stroke, meningitis, oxygen deprivation due to anoxia, mediated by PDE9 inhibition in a mammal comprising 45 hypoxia, or ischemia, brain tumor, infection (e.g. encephali administering to the mammal in need of Such treatment a tis), poisoning, Substance abuse, and the like. The present therapeutically effective amount of: (a) a compound of For invention is useful for the treatment of cognitive impairment mula (I), or a pharmaceutically acceptable salt thereof, or (b) and cognitive dysfunction resulting from brain injuries as a pharmaceutical composition comprising a compound of well as from neurodegenerative diseases and disorders. Formula (I), or a pharmaceutically acceptable salt thereof, in 50 The present invention also relates to methods for prevent a pharmaceutically acceptable vehicle, carrier or diluent; ing the above-described conditions in a mammal, including either alone or in combination with a second agent described human, comprising the steps of administering to the mammal above. an amount of: (a) a compound of Formula (I), or a pharma Conditions that may be treated, controlled or prevented by ceutically acceptable salt thereof, or (b) a pharmaceutical the methods of the present invention include diseases and 55 composition comprising a compound of Formula (I), or a disorders associated with neurodegeneration Such as: Alex pharmaceutically acceptable salt thereof, in a pharmaceuti ander disease, Alper's disease, Alzheimer's disease, amyo cally acceptable vehicle, carrier or diluent; either alone or in trophic lateral Sclerosis (ALS; also known as Lou Gehrig's combination with a second agent as described above, as part disease or motor neuron disease), ataxia-telangiectasia, Bat of an appropriate dosage regimen designed to prevent said ten disease (also known as Spielmeyer-Vogt-Sjogren-Batten 60 condition. disease), Binswanger's dementia (Subcortical arteriosclerotic The present invention also relates to methods for improv encephalopathy), bipolar disorders, bovine Spongiform ing cognitive deficits, including deficits in perception, con encephalopathy (BSE), Canavan disease, chemotherapy-in centration, learning, memory, communication, reasoning, duced dementia, Cockayne syndrome, corticobasal degenera and problem-solving. tion, Creutzfeldt-Jakob disease, depression, Down syndrome, 65 The appropriate dosage regimen, the amount of each dose frontotemporal lobar degeneration (including frontotemporal administered and the intervals between doses of the com dementia, semantic dementia, and progressive nonfluent pound will depend, among others, upon the compound of US 7,964,607 B2 25 26 Formula (I) of this invention being used, the type of pharma sulfate or mixtures thereof. In the case of capsules and tablets, ceutical compositions being used, the characteristics of the the dosage forms may further comprise buffering agents. Subject being treated and the type and severity of the condi Solid dosage forms may be formulated as modified release tions to be treated. In general, an effective dose for com and pulsatile release dosage forms containing excipients such pounds of Formula (I) or pharmaceutically acceptable salts as those detailed above for immediate release dosage forms thereof, is in the range of from about 0.1 mg to about 3,500 mg together with additional excipients that act as release rate per day. For a normal adult human having a body mass of modifiers, these being coated on and/or included in the body about 70 kg, a dosage in the range of from about 0.01 mg to of the device. Release rate modifiers include, but are not about 50 mg per kg body mass is typically sufficient, and limited to, hydroxypropylmethyl cellulose, methyl cellulose, 10 sodium carboxymethylcellulose, ethyl cellulose, cellulose preferably from about 0.2 to 2.5 mg per kg, in single or acetate, polyethylene oxide, Xanthan gum, ammoni divided doses daily. Administration may be in single (e.g., omethacrylate copolymer, hydrogenated castor oil, carnauba once daily) or multiple doses or via constant infusion. wax, paraffin wax, cellulose acetate phthalate, hydroxypro Some variability in the general dosage range may be pylmethyl cellulose phthalate, methacrylic acid copolymer required depending upon the age and mass of the Subject 15 and mixtures thereof. Modified release and pulsatile release being treated, the intended route of administration, the par dosage forms may contain one or a combination of release ticular compound being administered, and the like. The deter rate modifying excipients. mination of dosage ranges and optimal dosages for a particu The pharmaceutical compositions of the invention may lar mammalian subject is within the ability of a skilled person further comprise fast dispersing or dissolving dosage formu having benefit of the instant disclosure. lations (FDDFs). The terms dispersing or dissolving as used The compounds of Formula (I) may be administered by a herein to describe FDDFs are dependent upon the solubility variety of conventional routes of administration, including of the drug Substance used i.e., where the drug Substance is oral, buccal, Sublingual, ocular, topical (e.g., transdermal), insoluble, a fast dispersing dosage form may be prepared, and parenteral (e.g., intravenous, intramuscular, or Subcutane where the drug Substance is soluble, a fast dissolving dosage ous), rectal, intracisternal, intravaginal, intraperitoneal, intra 25 form may be prepared. vesical, local (e.g., powder, ointment, or drop), nasal and/or Solid compositions of a similar type may also be employed inhalation dosage forms or using a “flash' formulation, i.e., as fillers in Soft or hard filled gelatin capsules using Such allowing the medication to dissolve in the mouth without the excipients as lactose or milk Sugar, as well as high molecular need to use water. As will be recognized by one of skill in the weight polyethylene glycols and the like. art, the appropriate dosage regimen, the amount of each dose 30 Solid dosage forms such as tablets, dragees, capsules, and administered and the intervals between doses of the com granules can be prepared with coatings and shells, such as pound will depend upon the compound of Formula (I), or the enteric coatings and others well-known to one of ordinary prodrug thereof, being used, the type of pharmaceutical com skill in the art. They may also comprise opacifying agents, positions being used, the characteristics of the Subject being and can also be of Such composition that they release the treated, and/or the severity of the conditions being treated. 35 active compound(s) in a delayed, Sustained or controlled Methods of preparing various pharmaceutical composi manner. Examples of embedding compositions that can be tions with amounts of active ingredients are known, or will be employed are polymeric Substances and waxes. The active apparent in light of this disclosure, to those skilled in this art. compound(s) can also be in micro-encapsulated form, if See, for example, Remington's Pharmaceutical Sciences, appropriate, with one or more of the above-mentioned excipi Mack Publishing Co., Easton, Pa., 19th Ed. (1995). 40 entS. Suitable pharmaceutical carriers, vehicles and diluents for Liquid dosage forms for oral administration include phar Such compositions include inert Solid diluents or fillers, Ster maceutically acceptable emulsions, Solutions, Suspensions, ile aqueous solutions and various organic solvents. The phar syrups, and elixirs. In addition to the active compounds, the maceutical compositions formed by combining a compound liquid dosage form may contain inert diluents commonly of this invention and pharmaceutically acceptable carriers, 45 used in the art, such as water or other solvents, solubilizing vehicles or diluents are readily administered in a variety of agents and emulsifiers, as for example, ethanol, isopropanol, dosage forms such as tablets, powders, lozenges, syrups, ethyl carbonate, benzyl benzoate, propylene glycol. 1,3-bu injectable solutions and the like. tylene glycol, oils (in particular, cottonseed oil, groundnut oil, Solid dosage forms for oral administration include cap corn germ oil, olive oil, castor oil, and sesame seed oil), Sules, tablets, powders, and granules. In Such solid dosage 50 glycerol, tetrahydrofurfuryl alcohol, polyethylene glycols forms, the active compound is admixed with at least one inert and fatty acid esters of sorbitan, or mixtures of these sub conventional pharmaceutical excipient (or carrier) Such as stances, and the like. Sodium citrate, calcium carbonate, ordicalcium phosphate, or In addition to the active compound(s), the pharmaceutical (a) fillers or extenders. Such as for example, starches, lactose, composition may further include Suspending agents, such as Sucrose, mannitol and silicic acid; (b) binders, such as for 55 for example, ethoxylated isostearyl alcohols, polyoxyethyl example, carboxymethylcellulose, alginates, gelatin, polyvi ene Sorbitol and Sorbitan esters, microcrystalline cellulose, nylpyrrolidone. Sucrose and acacia; (c) humectants, such as aluminum metahydroxide, bentonite, agar-agar, and traga for example, glycerol; (d) disintegrating agents, such as for canth, or mixtures of these Substances, and the like. Sweet example, agar-agar, calcium carbonate, potato or tapioca eners, flavoring, and perfuming agents may also be included. starch, alginic acid, certain complex silicates, and sodium 60 The pharmaceutical compositions of the invention may carbonate; (e) solution retarders, such as for example, paraf further comprise adjuvants, such as preserving, wetting, fin, (f) absorption accelerators, such as for example, quater emulsifying and dispersing agents. Prevention of microor nary ammonium compounds; (g) wetting agents, such as for ganism contamination of the instant compositions can be example, cetyl alcohol and glycerol monostearate; (h) adsor accomplished with various antibacterial and antifungal bents, such as for example, kaolin and bentonite; and/or (i) 65 agents, for example, parabens, chlorobutanol, phenol, Sorbic lubricants, such as for example, talc, calcium Stearate, mag acid and the like. It may also be desirable to include isotonic nesium Stearate, Solid polyethylene glycols, Sodium lauryl agents, for example, Sugars, Sodium chloride and the like. US 7,964,607 B2 27 28 Prolonged absorption of injectable pharmaceutical composi -continued tions may be affected by the use of agents capable of delaying dd—doublet of doublets MPLC—medium pressure liquid absorption, for example, aluminum monostearate and gelatin. chromatography For parenteral administration, Solutions in Sesame or pea DMF-dimethylformamide MS-mass spectroscopy nut oil, aqueous propylene glycol, or in sterile aqueous solu DMSO–dimethylsulfoxide NMR nuclear magnetic resonance dt—doublet of triplets ppm parts per million tions may be employed. Such aqueous Solutions should be EtOAc—ethyl acetate psi—pounds per square inch suitably buffered if necessary and the liquid diluent first ren EtOH-ethanol s—singlet h (e.g., 1 h, 2h)—hour(s) SPA—scintillation proximity assay dered isotonic with Sufficient saline or glucose. These aque H (e.g., 1H, 2H)—hydrogen(s) t—triplet ous solutions are especially suitable for intravenous, intra 10 Hz—hertz THF tetrahydrofuran muscular, Subcutaneous and intraperitoneal administration. IPA—isopropyl alcohol Tris—tris(hydroxymethyl)amino methane In this connection, the sterile aqueous media employed are all J—spin-spin coupling constant readily available by Standard techniques known to those LC—liquid chromatography skilled in the art. 15 For intranasal administration or administration by inhala tion, the compounds of Formula (I) are conveniently deliv The methods disclosed in the instant Schemes and ered in the form of a solution or Suspension from a pump Examples are intended for purposes of exemplifying the spray container that is squeezed or pumped by the patient or instant invention only and are not to be construed as limita as an aerosol spray presentation from a pressurized container tions thereon. or a nebulizer, with the use of a Suitable propellant, e.g., Scheme 1 exemplifies multiple ways to form aliphatic dichlorodifluoromethane, trichlorofluoromethane, dichlo hydrazines that can utilized to prepare compounds in this rotetrafluoroethane, carbon dioxide or other suitable gas. In patent. Ketones can be converted to the hydrazide imine and the case of a pressurized aerosol, the dosage unit may be 25 reduced with borane or sodium cyanoborohydride. Other determined by providing a valve to deliver a metered amount. reducing agents can also be utilized. The boc group can then The pressurized container or nebulizer may contain a solution be removed with acid to form the desired hydrazine interme or Suspension of a compound of this invention. Capsules and diate. Alternatively aliphatic alcohols can be converted to cartridges (made, for example, from gelatin) for use in an boc-protected hydrazines by treatment with triphenyl phos inhaler or insulator may be formulated containing a powder 30 phine and di-t-butyl diaZacarboxylate. The boc groups can mix of a compound or compounds of the invention and a suitable powder base such as lactose or starch. again be removed with acid to liberate the hydrazine. Aro Pharmaceutical compositions of the present invention may matic hydrazine synthesis is well known in the literature by also be configured for treatments in Veterinary use, where a converting anilines to hydrazines through diazotization compound of the present invention, or a veterinarily accept 35 chemistry followed by reduction. able salt thereof, or veterinarily acceptable solvate or pro drug thereof, is administered as a suitably acceptable formu Scheme 1 lation in accordance with normal veterinary practice and the HN Veterinary practitioner will determine the dosing regimen and 40 n O H2NN - Boc NH route of administration which will be most appropriate for a N particular animal. 1) H B2H or NaCNBH In general, the compounds of Formula (I), and pharmaceu 2) HCI tically acceptable salts thereof, may be prepared according to 45 O O the exemplary routes disclosed in the Schemes and Examples HN below, as well as by other conventional preparative proce OH YNH dures known, or apparent in light of the instant disclosure, to Boc one of ordinary skill in the art. These processes form further 1) PPh3 Boc NSN aspects of the invention. 50 2) HCI Some of the starting compounds for the reactions described in the Schemes and Examples are prepared as illustrated O O herein. All other starting compounds may be obtained from general commercial sources, such as Sigma-Aldrich Corpo The pyrrolidine intermediates can be formed by coupling ration, St. Louis, Mo. 55 alpha-beta unsaturated esters with N-(methoxymethyl)(phe Unless indicated otherwise, the following experimental nyl)-N-(trimethylsilyl)methyl)methanamine which is com abbreviations have the indicated meanings: mercially available by catalysis with acid. This chemistry is exemplified in the experimental section below and also by 60 numerous literature examples such as Hosomi et al., Chem. IL-microliter m—multiplet Lett. 13(7) 1117-1120, 1984. The pyrrolidines have also been bd–broad doublet MHz—megahertz bm—broad multiplet Mins)—minute(s) synthesized in an enantiomeric pure fashion by either BOC-t-butoxycarbonyl MeOH-methanol employing chiral auxiliaries on the ester (see Nichols et al., bs—broad singlet Mg milligram CDCl-deuterated chloroform ml milliliter 65 Org. Lett., 8(7), 1495-1498, 2006) or by utilizing a chiral CDOD-deuterated methanol mmol—millimoles benzyl amine in the cycloaddition chemistry (see Haight et al., Org. Proc. Res. Dev, 8(6), 897-902, 2004). US 7,964,607 B2 29 30 -continued Scheme 2 O R R3N2 TFA, CH2Cl2 H 3n21N NN N COMe Mes;1 N1)ome R3 N as X R N 10 SOMe R3 s

N 15 The benzyl group can then be removed via standard hydro genation conditions to provide the secondary amine that is ready for further functionalization. The amine can be alky lated with alkyl halides in the presence of base or reductive amination chemistry utilizing a variety of hydride reducing Hydrazines can then be coupled in the presence of a base agents can provide the desired compounds. Such as sodium methoxide or triethylamine with 2-(ethoxym ethylene)malononitrile or substituted variants to afford the 25 desired amino cyano pyrazoles. The cyano group can be Scheme 4 O oxidized by a variety of reagent but two conditions have been R utilized to prepare compounds for this patent. Concentrated H Sulfuric acid or hydrogen peroxide with ammonium hydrox NN N H2, Pd/C or 30 R3 N Pd(OH)2 ide has afforded the amino-amide-pyrazoles. The amino He wS M amide pyrazoles can then be coupled with esters in the pres v N N ence of a base such as potassium t-butoxide with heated. The R solvent of choice for this reaction has been tetrahydrofuran and in Some cases dehydrating agents such as molecular sieves can be employed to improve upon the yields of the 35 coupling.

Scheme 3 40 o O R EtOH, Base (OEt or Et3N) Hn R2CHO, NaBH(OAc)3 N N or NaCNBH RN-NH2N - NC CN - R3 N Hs H als \ O 45 N V Ri OEt R HN R O NC H2O2, NH4OH R N or H2SO4 H a R2-X (Br, I, Cl, ect.) 50 | MN R3 N NN - Base (CsCO),He DMFor THF HN N WS N^ R N V O R R N Base such as KOtBu 55 M HN N in THF 60° C. -e- R2 O N SOMe R HN N R3 s H R n N N 60 R3 N

N V R N M 65 US 7,964,607 B2 31 32 EXAMPLES (c) (3,4-trans)-methyl 1-benzyl-4-methylpyrrolidine 3-carboxylate The Examples below are intended to illustrate particular embodiments of the invention and preparations thereto and are not intended to limit the specification, including the 5 claims, in any manner. Unless otherwise noted, all reagents S OMe employed were obtained commercially. Example 1 10 so (a) 5-amino-1-(2-methoxyphenyl)-1H-pyrazole-4- carbonitrile

15 NC

Y.M To a solution of (E)-methylbut-2-enoate (1.6 g) was added HN N toluene (30 mL), N-(methoxymethyl)(phenyl)-N-((trimeth OMe ylsilyl)methyl)methanamine (3.7g) and trifluoroacetic acide (1.5 g). The reaction mixture was heated at 50° C. for 18 h. The reaction mixture was concentrated, quenched with Satu rated sodium bicarbonate, extracted with methylene chloride, 25 dried with magnesium sulfate, filtered and concentrated. To a solution of 1-(2-methoxyphenyl)hydrazine hydrogen Purification via MPLC chromatography eluting with 20-30% chloride (3 g, 0.017 mol) in ethanol (50 mL) was added ethyl acetate/hexanes provided the title compound (1.5 g). 2-(methoxymethylene)malononitrile (1.89 g, 0.9 eq) and 400 MHz H NMR (CDC1) & 7.33-7.20 (m, 5H), 4.15-4.08 Sodium methoxide (1.92g, 2.1 eq). The reaction mixture was (m. 1H), 3.66-3.53 (m, 2H), 2.87-2.74 (m, 2H), 2.53-2.44 (m, heated at reflux for 18h and concentrated. The reaction mix 30 2H), 2.23-2.19 (m, 1H), 1.23 (t, J=7.1 Hz, 3H), 1.11 (d. J–6.6 ture was partitioned between brine and ethyl acetate. The Hz, 3H). organic layer was separated, dried with magnesium sulfate, filtered and concentrated. MPLC Biotage chromatography (d) 6-(3,4-trans)-1-benzyl-4-methylpyrrolidin-3-yl)- eluting with 20-60% ethyl acetate/hexanes afforded the title 1-(2-methoxyphenyl)-1,5-dihydro-4H-pyrazolo 3,4- compound in 53% yield (1.9 g). 400 MHz H NMR (CDC1) 35 dpyrimidin-4-one 87.64 (m, 1 H), 7.40 (m, 2H), 7.08 (m.2H), 4.51 (bs, 2H), 3.87 (s, 3 H); MS: (MH m/z =215.2). (b) 5-amino-1-(2-methoxyphenyl)-1H-pyrazole-4- carboxamide 40

45 HN

HN OMe 50 To (3,4-trans)-methyl 1-benzyl-4-methylpyrrolidine-3car boxylate (241 mg) and 5-amino-1-(2-methoxyphenyl)-1H pyrazole-4-carboxamide (200 mg) was added a solution of To a solution of 5-amino-1-(2-methoxyphenyl)-1H-pyra 55 Zole-4-carbonitrile (1.53 g) in Saturated ammonium hydrox potassium t-butoxide in (1M) in THF (4.31 mL, 5 eq.) The ide (30 mL) was added 30% hydrogen peroxide solution (6 reaction mixture was heated at reflux for 16 hand poured into mL). The reaction stirred for 18 hat ambient temperature and saturated Sodium bicarbonate. The aqueous layer was was slowly quenched with 60 mL of a saturated sodium extracted with ethyl acetate, dried with magnesium sulfate, sulfate solution. The aqueous layer was extracted with ethyl 60 filtered and concentrated. MPLC Biotage chromatography acetate, dried with magnesium sulfate, filtered and concen eluting with 1-4% methanol/methylene chloride with 0.5% trated. MPLC Biotage chromatography eluting with 2-6% saturated ammonium hydroxide provided 79 mg of the title methanol/methylene chloride provided the title compound compound. 400 MHz H NMR (DMSO) & 8.16 (d. J=7.9 Hz, 1.38 g (84%). 400 MHz H NMR (DMSO) & 7.79 (s, 1 H), 1H), 7.92 (s, 1 H), 7.34 (m, 5H), 7.09 (m, 1H), 6.92 (m, 2H), 7.42 (m, 1H), 7.25 (d. J=7.5 Hz, 2H), 7.19 (d. J=8.3 Hz, 2 H), 65 3.89 (s.3H), 3.84 (m. 1H), 3.71 (m. 1H), 3.37 (t, J=9.1 Hz, 7.03 (t, J=6.2 Hz, 1H), 5.83 (s.2H), 3.76 (s.3 H); MS: (M*H 1H), 3.09 (m. 1H), 2.85 (m, 1H), 2.65 (m, 1H), 2.47 (m. 1H), m/Z 233.2). 2.03 (m, 2H), 1.19 (d. J=7.1 Hz,3H); MS: (MH m/z-416.1). US 7,964,607 B2 33 34 Example 2 Example 4 (a) 1-cyclopentyl-6-(3,4-trans-4-methylpyrrolidin-3- 6-I(3,4-trans)-1-benzyl-4-methylpyrrolidin-3-yl)-1- yl)-1H-pyrazolo 3,4-dipyrimidin-4(5H)-one cyclopentyl-1,5-dihydro-4H-pyrazolo 3,4-dipyrimi 5 din-4-one

O

H O 10

N s ll.s N WN Y | N XN 15

A solution of 6-(3,4-trans)-1-benzyl-4-methylpyrrolidin 3-yl)-1-cyclopentyl-1,5-dihydro-4H-pyrazolo 3,4-dipyrimi din-4-one (970 mg) in ethanol 25 mL was added to a Parr bottle. Acetic acid (2.5 mL) and Pd(OH)2 (500 mg) was Following the procedure for the preparation of 6-(3,4- added. The reaction mixture was placed on a hydrogenator trans)-1-benzyl-4-methylpyrrolidin-3-yl)-1-(2-methoxyphe under 40 PSI for 16 h. The reaction mixture was filtered nyl)-1,5-dihydro-4H-pyrazolo 3,4-dpyrimidin-4-one but 25 through Celite and concentrated. The reaction mixture was Substituting 5-amino-1-cyclopentyl-1H-pyrazole-4-carboxa partitioned between saturated bicarbonate solution and meth ylene chloride. The layers were separated and the aqueous mide provided the title compound. 400 MHz H NMR layer was extracted 6x with methylene chloride. The organic (CDOD) & 8.00 (s, 1H), 7.38-7.23 (m, 5H), 5.14-5.10 (m, layer was dried with magnesium Sulfate, filtered and concen 1H), 3.80-3.57 (m, 2H), 3.34 (t, J=8.3 Hz, 1H), 2.97 (d. J=9.9 30 trated to provide 429 mg of the title compound. 400 MHz "H HZ, 1H), 2.80-2.78 (m. 1H), 2.53-2.49 (m. 1H), 2.41-2.38 (m, NMR (CDOD) & 9.25 (brs, 1H), 8.02 (s, 1H), 5.20-5.17 (m, 1H), 2.10-1.89 (m, 7H), 1.70- 1.66 (m. 2H), 1.17 (d. J=6.6 Hz, 1H), 3.91 (m, 1H), 3.77-3.68 (m,2H), 3.46-3.44 (m, 1H), 3.10 3H). MS: (MH m/z =378.1). (m. 1H), 2.89 (m. 1H), 2.13-1.87(m, 6H), 1.74-1.65 (m, 2H), 1.20 (d. J=6.2 Hz, 3H). MS: (MH m/z-288.1). 35 Example 3 (b) 1-cyclopentyl-6-(3,4-trans)-4-methyl-1-4-(trif luoromethyl)pyrimidin-2-ylpyrrolidin-3-yl)-1,5- 6-(3S4S)-1-benzyl-4-methylpyrrolidin-3-yl)-1- dihydro-4H-pyrazolo 3,4-dpyrimidin-4-one cyclopentyl-1,5-dihydro-4H-pyrazolo 3,4-dipyrimi din-4-one 40

Rac

O 45 N

anWN| CN 50

Y s

55 To a solution of 1-cyclopentyl-6-(3,4-trans)-4-methylpyr The racemate was separated on Chiralcel OD chiral HPLC rolidin-3-yl)-1H-pyrazolo 3,4-dipyrimidin-4(5H)-one (40 column, Mobile Phase 90/10 Heptane/EtOH, T=6.807, to mg) in dimethylformamide (1 ml) was added cesium carbon provide the enantiomer. 400 MHz HNMR (CDC1) 88.00 (s, ate (2 eq.) and 2-chloro-4-(trifluoromethyl)pyrimidine (1.2 60 eq.) and the reaction mixture was heated at 60° C. for 90 min. 1H), 7.38-7.22 (m, 5H), 5.27-5.10 (m. 1H), 3.78 (d. J=12.5 The reaction mixture was poured into Saturated sodium bicar HZ, 1H), 3.6 (d. J=12.5 Hz, 1H), 3.34 (t, J=8.3 Hz, 1H), 2.97 bonate, extracted with methylene chloride, dried with mag (d. J=9.9 HZ, 1H), 2.80-2.78 (m. 1H), 2.52-2.48 (m. 1H), nesium sulfate, filtered and concentrated. Purification via 2.41-2.38 (m. 1H), 2.10-1.89 (m, 7H), 1.70-1.66 (m, 2H), MPLC Biotage chromatography eluting with 20-60% ethyl 1.18(d, J=6.6 Hz, 3H). MS: (MH m/z-378.1). 65 acetate/hexanes provided 40 mg of the title compound. 400 Chiralcel OD, Mobile Phase 90/10 Heptane/IPA, MHz H NMR (CDC1) & 8.51 (d. J=5.0 Hz, 1H), 8.02 (m, T=9.433. 1H), 6.79 (d. J–4.6 Hz, 1H), 5.16-5.08 (m. 1H), 4.243.97 (m, US 7,964,607 B2 35 36 3H), 3.37-3.32 (m, 1H), 3.20-3.14 (m, 1H), 2.09-2.05 (m, vided the title compound (27 mg). 400 MHz H NMR 3H), 1.96-1.90 (m. 1H), 1.73-1.56 (m, 5H), 1.24 (d. J=6.6 Hz, (CDC1) & 8.06-8.03 (m. 1H), 7.57-7.50 (m, 2H), 743-7.37 3H). MS: (MH m/z-434.1). (m,3H), 5.20-5.13 (m. 1H), 4.16-4.03 (m. 1H), 3.92 (d. J=8.3 HZ, 1H), 3.81-3.76 (m. 1H), 3.47-3.29 (m. 1H), 3.17-3.03 (m, Example 5 1H), 2.84-2.67 (m. 1H), 2.11-1.80 (m, 3H), 1.79-1.72 (m, 1-cyclopentyl-6-(3,4-trans)-4-methyl-1-pyrimidin 1H), 1.56-1.30 (m, 4H), 1.21-1.11 (m, 3H). MS: (M*H 2-ylpyrrolidin-3-yl)-1,5-dihydro-4H-pyrazolo 3,4-d m/Z392.1). pyrimidin-4-one Example 7 10 1-cyclopentyl-6-(3,4-trans)-4-methyl-1-(pyridin-3- Rac ylmethyl)pyrrolidin-3-yl)-1,5-dihydro-4H-pyrazolo 3,4-dipyrimidin-4-one

15 Rac

25 Following the procedure for the preparation of 1-cyclopen tyl-6-(3,4-trans)-4-methyl-1-4-(trifluoromethyl)pyrimi din-2-ylpyrrolidin-3-yl)-1,5-dihydro-4H-pyrazolo 3,4-d e pyrimidin-4-one but Substituting 2-chloropyrimidine provided the title compound. 400 MHz H NMR (CDOD) & 30 To a solution of 1-cyclopentyl-6-(3,4-trans)-4-methylpyrro 8.29 (d. J=5.0 Hz, 2H), 7.96 (s, 1H), 6.60 (t, J=5.0 Hz, 1H), lidin-3-yl)-1H-pyrazolo 3,4-dpyrimidin-4(5H)-one (40 mg) 5.08-5.04 (m, 1H), 4.06-3.87 (im, 3H), 3.23-3.18 (m, 1H), in 1,2-dichloroethane (2 mL) was added acetic acid (2 eq.), 3.12 (q, J–7.9 HZ, 1H), 2.80-2.76 (m, 1H), 2.05-1.98 (m, 4), nicotinaldehyde (1.5 eq.) and sodium triacetoxy borohydride 1.90-1.82 (m, 2H), 1.66-1.61 (m, 2H), 1.17 (d. J=7.1 Hz, 3H). (58 mg). The reaction mixture was heated at 40°C. for 4 h, MS: (MH m/z-366.1). 35 poured into Saturated sodium bicarbonate, extracted with methylene chloride, dried with magnesium sulfate, filtered Example 6 and concentrated. Purification via Biotage MPLC chroma tography eluting with 1-4% methanol/methylene chloride/ 6-I(3,4-trans)-1-benzoyl-4-methylpyrrolidin-3-yl)-1- 0.5% ammonium hydroxide provided the title compound (47 cyclopentyl-1,5-dihydro-4H-pyrazolo 3,4-dipyrimi 40 mg).400 MHz H NMR (CDC1) & 8.55 (m, 2H), 2.02 (s, 1H), din-4-one 7.84 (m. 1H), 7.36 (m, 1H), 5.16-5.09 (m, 1H), 3.82-3.60 (m, 2H), 3.36 (m, 1H), 3.05-2.38 (m, 4H), 2.13-1.89 (m, 7H), 1.73-1.68 (m, 2H), 1.21 (m, J=7.1 Hz, 3H). MS: (M*H Rac m/z–379.1). O 45 Example 8 N N N \ / 1-cyclopentyl-6-(3,4-trans)-4-methyl-1-3-(trifluo romethyl)benzylpyrrolidin-3-yl)-1,5-dihydro-4H SAN S. N 50 pyrazolo 3,4-dipyrimidin-4-one

N Rac O 55 F O F

F N To a solution of 1-cyclopentyl-6-(3,4-trans)-4-methylpyrro M lidin-3-yl)-1H-pyrazolo 3,4-dipyrimidin-4(5H)-one (40 mg) 60 N in methylene chloride (1 ml) was added triethyl amine (2.5 eq.) and benzoyl chloride (1.2 eq.) and the reaction mixture was stirred at ambient temperature for 1 h. The reaction mixture was poured into Saturated Sodium bicarbonate, extracted with methylene chloride, dried with magnesium 65 sulfate, filtered and concentrated. Biotage MPLC chromatog Following the procedure for the preparation of 1-cyclopen raphy eluting with 2–4% methanol/methylene chloride pro tyl-6-(3,4-trans)-4-methyl-1-(pyridin-3-ylmethyl)pyrroli

US 7,964,607 B2 69 70 Example 60 1H), 4.29-4.21 (m, 1H), 4.02 (dd, J=11.6, 4.6 Hz, 2H), 3.28 (t, J=1.7 Hz, 2H), 2.12-2.02 (m, 2H), 1.80-1.76 (m, 2H). MS: (a) 1-(tetrahydro-2H-pyran-4-yl)hydrazine (MH m/z-193.1).

5 (c) 5-amino-1-(tetrahydro-2H-pyran-4-yl)-1H-pyra Zole-4-carboxamide HN NH

10

HN O

HN To a solution of tetrahydropyran-4-one (71.6 g. 715 mmol) 15 in methanol (2 L) was added tert-butylcarbazate (100 g, 758 mmol) at ambient temp. The mixture was stirred at ambient temp for 20 h. The reaction mixture was concentrated under reduced pressure to dryness to afford a white solid (154 g). To a suspension of the white solid (154g, 715 mmol) in water (1 L) was added acetic acid (500 mL, 8.73 mol) and the mixture A stirred solution of 5-amino-1-(tetrahydro-2H-pyran-4- was stirred for 30 minto get a clear solution. To this solution, yl)-1H-pyrazole-4-carbonitrile (-228 mmol) in ethanol (300 solid NaCNBH (44.5g, 708 mmol) was added portion-wise. mL) was treated with 35% aqueous HO (100 mL) followed The mixture was stirred at ambient temp for 2 h. The mixture by aqueous ammonia (300 mL). The reaction mixture was was then transferred to a 12 L flask, cooled to 0° C., and 25 stirred for 48 h at ambient temp and then quenched with aq quenched with 1NNaOH (8.73L, 8.73 mol). The mixture was saturated sodium thiosulfate (800 mL) and concentrated extracted with CHCl (3x3 L) and dried over NaSO. The under reduced pressure to remove most of the ethanol. The organic layer was filtered and concentrated to afford a white resulting solid was removed by filtration and washed with solid (164 g, contains ~15% of N-acetyl-N'-Boc-hydrazine water (2x200 mL) and ether (2x150 mL). The solid was dried derivative). Chromatography silica, ethyl acetate/MeCH 30 in vacuo to constant weight (31 g, 65% yield for 2 steps). 400 (95:5 gave 94 g of 90% pure boc-hydrazine. A solution of MHz H NMR (CDOD) & 7.67 (s, 1H), 4.27-4.21 (m. 1H), boc-hydrazine (50g, 231 mmol) in methanol (500 mL) was 4.03 (dd, J=11.6, 4.6 Hz, 2H), 3.28 (t, J=1.7 Hz, 2H), 2.14 added a solution of HCl in dioxane (462 mL, 1.85 mol. 4.0 2.04 (m, 2H), 1.81-1.78 (m, 2H). MS: (MH m/z 382.2). M). The mixture was stirred at ambient temp overnight. Con centration of the reaction mixture under reduced pressure 35 (d) 6-(3,4-trans)-1-benzyl-4-methylpyrrolidin-3-yl)- afforded the title compound as a white solid (43 g.98%). 400 1-(tetrahydro-2H-pyran-4-yl)-1,5-dihydro-4H-pyra MHz. "H NMR (DMSO) & 3.85-3.82 (m, 2H), 3.27-3.21 (m, Zolo3,4-dipyrimidin-4-one 2H), 3.13-3.05 (m, 1H), 1.88-1.84 (m, 2H), 1.48-1.38 (m, 2H). MS: (M+H m/z =117.2). 40 (b) 5-amino-1-(tetrahydro-2H-pyran-4-yl)-1H-pyra Zole-4-carbonitrile O

45 NC “4 N | MN ry HN N N M 50

O

O To a mixture of 5-amino-1-(tetrahydro-2H-pyran-4-yl-1H 55 pyrazole-4-carboxamide (6.0g, 28.54 mmol) and (3,4-trans)- To a mixture of 1-(tetrahydro-2H-pyran-4-yl)hydrazine di methyl 1-benzyl-4-methylpyrrolidine-3-carboxylate (13.3 g, hydrogen chloride (18 g., 96 mmol) in 200 mL of EtOH was 57.08 mmol) was added molecular sieves (pellets). To the added EtN (30 g, 40 mL, 288 mmol) at 0°C. (ice bath). The stirred mixture was added a 1.0 M solution oft-BuOK in THF resulting mixture was stirred for 1 h, then a solution of (57.1 ml, 57.08 mmol) and the resulting mixture was heated at 2-(ethoxymethylene)malononitrile (12 g, 96 mmol) in 100 60 reflux under an atmosphere of nitrogen with vigorous stirring mL of EtOH was added slowly to keep the reaction temp overnight. Analysis of the reaction mixture by LC/MS indi below 5°C. This mixture was stirred at ambient temp over cated consumption of the starting material. The reaction mix night and then heated to reflux for 2 hr. After removal of the ture was cooled to ambient temp and solids were removed by solvent under vacuum, the residue was washed with 300 mL filtration. The solids were washed with EtOAc (2x) and the of water. The solid was collected, washed with additional 200 65 combined filtrates were concentrated under reduced pressure. mL of water, 200 mL of 1:1 of hexane and ether, dried to give The remainder was partitioned between CH2Cl and HO and 17 g of yellow solid. 400 MHz H NMR (CDOD) & 7.71 (s, the aqueous and organic layers were separated. The aqueous US 7,964,607 B2 71 72 phase was extracted with CHCl (1x) and the combined 7.32-7.21 (m, 5H), 4.18-4.10 (m, 2H), 3.67-3.55 (m, 2H), organic extracts were dried over NaSO, filtered and con 2.90-2.63 (m, 4H), 2.43-2.34 (m, 2H), 2.24-2.15 (m, 1H), centrated under reduced pressure. The remaining residue was 1.27-1.22 (m, 3H), 0.88-0.85 (m. 1H). purified by chromatography (silica gel, 1% EtN in EtOAc) to afford the title compound (7.8 g. 70% yield) as an off-white 5 (b) 6-(3,4-trans)-1-benzyl-4-(2.2.2-trifluoroethyl) solid. 400 MHz H NMR (CDC1) & 8.02 (s, 1H), 7.39-7.25 pyrrolidin-3-yl)-1-cyclopentyl-1,5-dihydro-4H-pyra (m, 6H), 4.83-4.75 (m. 1H), 4.14-4.09 (m, 2H), 3.82 (m, 1H), Zolo3,4-dipyrimidin-4-one 3.62-3.54 (m,3H), 3.39-3.37 (m, 1H), 3.00 (m, 1H), 2.83 (m, 1H), 2.66-2.27 (m, 4H), 2.10-1.83 (m,3H), 1.20 (d. J=6.6 Hz, 3H). MS: (MH m/z-394.2). 10 Example 61 6-(3S4S)-1-benzyl-4-methylpyrrolidin-3-yl)-1- (tetrahydro-2H-pyran-4-yl)-1,5-dihydro-4H-pyrazolo 15 3,4-dipyrimidin-4-one

O

25 ... -N Following the procedure for the preparation of 6-(3,4- r NN trans)-1-benzyl-4-methylpyrrolidin-3-yl)-1-(2-methoxyphe N M nyl)-1,5-dihydro-4H-pyrazolo 3,4-dpyrimidin-4-one but Substituting 5-amino-1-cyclopentyl-1H-pyrazole-4-carboxa O mide and (3,4-trans)ethyl-1-benzyl-4-(2.2.2-trifluoroethyl) pyrrolidine-3-carboxylate provided the title compound. 400 The racemate of Example 60 was separated on Chiralcel MHz H NMR (CDC1,) & 8.02 (s, 1H), 7.36-7.26 (m, 5H), OD-H chiral HPLC column, Mobile Phase 70/30 Heptane/ 5.12-5.08 (m, 1H), 3.85-3.81 (m. 1H), 3.60-3.57 (m, 1H), EtOH, T=11.465, to provide the enantiomer. 400 MHz H 35 3.42 (t, J=8.3 Hz, 1H), 3.02-2.96 (m, 2H), 2.64 (m. 1H), NMR (CDC1) & 8.02 (s, 1H), 7.39-7.25 (m, 6H), 4.82-4.76 2.53-2.44 (m, 2H), 2.34-1.89 (m, 6H), 1.81-1.62 (m, 4H). (m. 1H), 4.14-4.09 (m, 2H), 3.82-3.79 (m, 1H), 3.62-3.54 (m, 3H), 3.37 (d. J–8.7 Hz, 1H), 3.00 (d. J=9.9 Hz, 1H), 2.79 (dd, Example 63 J=6.3, 2.5 Hz, 1H), 2.52-2.48 (m, 1H), 2.42-2.30 (m, 3H), 1.94-182 (m, 3H), 1.20 (d. J=6.6 Hz, 3H). MS: (M*H 40 m/Z394.2). (a) 1-(4,4-difluorocyclohexyl)hydrazine Example 62

45 (a) (3,4-trans)-ethyl-1-benzyl-4-(2.2.2-trifluoroethyl) HN pyrrolidine-3-carboxylate NH

50

55 To a solution of 4,4-difluorocyclohexanol (0.9 g) in toluene was added triphenyl phosphine (2.6 g) and di-t-butyldiazac arboxalate (1.82 g) and the reaction mixture stirred for 18 h. The reaction mixture was concentrated and methanol was 60 added (13 mL). To the methanol solution HCl in dioxane (4M, 13 mL) was added. The reaction mixture was stirred for 3 h and concentrated. The reaction mixture was partitioned between water and ethyl acetate. The layers were separated Following the procedure for the preparation of (3,4-trans)- and the aqueous layer was extracted 3x with ethyl acetate. methyl-1-benzyl-4-methylpyrrolidine-3-carboxylate but 65 The organic layer was dried with magnesium sulfate, filtered substituting (E)-methyl-5.5.5-trifluoropent-2-enoate pro and concentrated. The title compound was used without puri vided the title compound. 400 MHz H NMR (CDC1) & fication in the preparation of 5-amino-1-(4,4-difluorocyclo

US 7,964,607 B2 105 106 bottom microtiter plates (Costar 3632, Corning Inc). The -continued human recombinant PDE9 enzyme was generated in SF-9 cells, the cell pellets were sonicated in buffer (20 mM TRIS, GS678A 2 mM benzamidine, 1 mM EDTA, 250 mM sucrose, 100 uM Example No. (U): IC50 PMSF, pH 7.5 with HCl), centrifuged at 40,000xg for 20 min 5 at 4° C. The supernatants were stored at -80° C. 8-H 3. guanosine 3',5'-cyclic phosphate (TRK392, GE Healthcare S4 14.7nM Life Sciences) was diluted in assay buffer (50 mM Tris-HCl, 55 6.55 nM pH7.5, containing 1.3 mM MgCl) such that the final well 56 4.81 nM concentration was 50 nM. Test compounds were dissolved in 10 57 122nM DMSO, diluted in DI HO and serially diluted in 20% 58 334 nM DMSO/80%HO, for a final concentration of 2% DMSO. For 59 7.37 nM the assay the PDE9 was diluted with assay buffer such that 60 44.8 nM 20% or less of the substrate was hydrolyzed to 5'GMP. Each 2. s assay well contained 10ul of test compound or solvent, 40 ul 15 63 123 N of HICGMP and 50 ul of enzyme, background was deter- 64 873 l M mined by a high concentration of a PDE inhibitor. The assay 65 17.1 nM was initiated with the addition of the enzyme and carried out 66 18.1 nM at room temperature for 30 min. The assay was terminated 67 9.74 nM with the addition of 10 ul of a PDE9 inhibitor that was suffi- 20 68 36.7 nM cient to totally inhibit the enzyme activity, immediately fol- 69 30.7nM lowed by the addition of 50 ul per well of SPA beads. The 70 10.2nM plates were sealed, vortexed, allowed to set for >300 min, 7. 2. then counted in a Wallac TriLux MicroBeta LSC. l 73 6.O1 nM 25 74 6.14 nM 75 5.46 nM GS678A 76 3.50 nM Example No. (U): IC50 77 1.24 nM 78 4.35 nM 3 9.46 nM 30 79 3.72 nM 4 624 nM 8O 3.72 nM 5 SS8 nM 81 2.92 nM 6 57.1 nM 82 5.18 nM

...Allg M 83 24.5 nM 9 2.84 nM 35 84 187nM 10 4.98 nM 85 O.903 nM 11 18.9 nM 86 1.44 nM 12 7.23 M 87 5.72 nM 13 6.61 nM 88 17.9 nM 14 26.0 nM 89 1.70 nM 17 16.2nM 40 90 1.41 nM 18 8.26 nM 91 6.69 nM 19 2.68 nM 2O 7.06 nM 92 23.3 nM 21 34.5 nM 93 24.3 nM 22 43.6 nM 94 14.2nM 23 1.32 nM 95 3.92 nM 24 119 nM 45 96 7.13 M 25 9.07M 97(a) 7.20 nM 26 11.4 nM 97(b) S.S6M

5. 6.N.l 98 7.93 M 29 2.17 nM 99 12.8nM 31 23.2nM 50 OO 22.7 nM 32 5.19 nM O1 7.94 nM 33 6.29 nM O2 19.7 nM 34 4.33 nM O3 15.2nM 35 53.8 nM 36 5.08 nM O4 3.98 nM 37 3.23 nM 55 05 3.29 nM 38 5.75 nM O6 8.06 nM 39 58.1 nM O7 4.33 nM 40 44.5 nM O8 3.11 nM

3. 's lM 09 4.21 nM 43 36.4 nM 10 2.59 nM 44 10.9 nM 60 11 12.5 nM 45 38.7M 12 1.37 nM 46 8.53 nM 13 <1.00 nM 47 S.S3 M 14 2.31 nM 48 40.7nM 49 4.55 nM 50 125 nM 65 51 8.19 nM The following additional compounds were made in accor dance with the methods set forth above:

US 7,964,607 B2 171 172 -continued

Obs. Exact Molec. m2 Retention Structure IUPACNAME (U):IC50 Mass Weight (M + 1) Time 1-cyclopentyl-6-(3,4- 3.78 M 432.239 660.581 (433.2} trans)-4-methyl-1-(1- methyl-1H-imidazo[4,5- cpyridin-2- yl)methylpyrrollidin-3-yl)- 1,5-dihydro-4H pyrazolo 3,4-dpyrimidin 4-one

227 Rac 1-cyclopentyl-6-(3,4- 413.203 527.496 (414.2} trans)-1-(3,5- difluorobenzyl)-4- methylpyrrollidin-3-yl)-1,5- dihydro-4H-pyrazolo 3,4- dpyrimidin-4-one

228 Rac O 1-cyclopentyl-6-(3,4- 49.1 nM 407.243 521.546 (408.3} trans)-1-(5,6-dihydro-4H pyrrolo.1,2-bipyrazol-3- ylmethyl)-4- methylpyrrollidin-3-yl)-1,5- dihydro-4H-pyrazolo 3,4- dpyrimidin-4-one

Although certain presently preferred embodiments of the as heterocycloalkyl, aryl, and heteroaryl, each of which invention have been described herein, it will be apparent to optionally may be substituted with one to three substitu those skilled in the art to which the invention pertains that ents, the Substituents being independently selected from variations and modifications of the described embodiments the group consisting of (C-C)alkyl, (C-C)alkoxy, may be made without departing from the spirit and scope of halo, and (C-C)haloalkyl, the invention. Accordingly, it is intended that the invention be so R is selected from the group consisting of hydrogen, (C- limited only to the extent required by the appended claims and C.)alkyl, (C-C)alkenyl, (C-C)alkynyl, (C-C)ha the applicable rules of law. loalkyl, and cyclopropyl; We claim: R is selected from the group consisting of (C-C)alkyl, 1. A compound of Formula (I), (I) (C-C)alkenyl, (C-C)alkynyl, (C-C)haloalkyl, het O R 55 eroaryl selected from the group consisting of pyridinyl, H pyridazinyl, pyrimidinyl, and pyrazinyl, and ERs, NN N wherein the heteroaryl optionally may be substituted R3 N with one to three substituents independently selected from the group consisting of (C-C)alkyl and (C-C) ls, N?V 60 haloalkyl: R R is selected from the group consisting of hydrogen, (C- N C.)alkyl, (C-C)alkenyl, (C-C)alkynyl, (C-C)cy W R2 cloalkyl, and (C-C)haloalkyl: E is selected from the group consisting of —CH2—, or a pharmaceutically acceptable salt thereof, wherein: 65 R is selected from the group consisting of (C-C)alkyl, Rs is selected from the group consisting of (C-C)cy (C-C)alkenyl, (C-C6)alkynyl, (C-Cs)cycloalkyl, cloalkyl, heterocycloalkyl, aryl, aryloxy, and heteroaryl,