WO2005111030A1 - Quinolone antibacterial agents - Google Patents

Abstract

Compounds of formula (I) and methods for their preparation are disclosed. Further disclosed are methods of making biologically active compounds of formula (I) as well as pharmaceutically acceptable compositions comprising compounds of formula (I). Compounds of formula (I) as disclosed herein can be used in a variety of applications including use as antibacterial agents. A compound of formula (I):

Description

QUINOLONE ANTIBACTERIAL AGENTS

The present application claims priority to U.S. Provisional Patent Application Serial No. 60/570,142 filed May 12, 2004, the entire contents of which are hereby incorporated by reference. FIELD The invention relates to compounds bearing a quinolone core structure which exhibit antibacterial activity, methods for their preparation, as well as pharmaceutically acceptable compositions comprising such compounds. BACKGROUND Antibacterial resistance is a global clinical and public health problem that has emerged with alarming rapidity in recent years. Resistance is a problem in the community as well as in health care settings, where transmission of bacteria is greatly amplified. Because multiple drug resistance is a growing problem, physicians are now confronted with infections for which there is no effective therapy. The morbidity, mortality, and financial costs of such infections pose an increasing burden for health care systems worldwide. Yet active compounds are of no assistance if they are toxic. Thus, for example, although sparfloxacin exhibits a favorable activity profiles, it has also been shown to prolong the QT interval. Moreover, concerns over the potential for proarrhythmia have recently prompted the withdrawal of grepafloxacin from the market. As a result, there is also a need for improved agents with favorable antibacterial activities, particularly against resistant bacterial strains, as well as reduced toxicity profiles. SUMMARY These and other needs are met by the present invention, which is directed to a compound of formula I:

or a pharmaceutically acceptable salt thereof, wherein: X is N or C, provided that when X is N, R₅ is absent at that position;

R_T is (C C₆)alkyI, halo(CrC₆)alkyl, (C₃-C₆)cycloalkyl, halo(C₃-C₆)cycloalkyl aryl, and heteroaryl; R₂ is OH, Old-CeJalkyl, O(C₃-C₆)cycloalkyl, O 0-(CHR_2a)_m-0 QR₂b _j wherein m is an integer of from 1 to 10, Q is O or is absent, and R_2a is H or (CrC₆)alkyl and R_2b is (C C₆)alkyl, aryl, or heteroaryl, O- (CHR_2a)n^{— γ} _t wherein R_2a is as defined above, n is an integer of from 2 to 10, Y is OH or R_2oR₂d, wherein R_2o and R₂d are each independently H, (C|-C₆)alkyl, or (C₃-C₆)cycloalkyl, or NR_2d, wherein R_2d is as defined above,

_t wherein " ^■"*^»*■ " indicates the point of attachment, 2a is as defined above, R_2θ is H or (CτC₆)alkyl, e is an integer of from 1 to 10, p is an integer of from 2 to 10, and Xi and Yi are each independently NH or O; R₃, R₄, and R₅ are each independently H, halo, NH₂, (C C₆)alkyl, halo(C C₆)alkyl, (CrC₆)alkoxy, or halo(CrC₆)alkoxy; R_a and R_b are each independently H, (CrC₆) alkyl, haloalkyl, halo, or R_a and R taken together with the carbon to which they are attached form a 3,4,5 or 6-membered ring; and R₀ and R_d are each independently H or (C C₆)alkyl. What is also provided is a compound which is:

,4-

,4-

What is also provided is a compound which is:

,4-

,4-

,4-

What is also provided is a compound which is:

What is also provided is a compound which is:

What is also provided is a compound which is:

What is also provided is a pharmaceutical formulation comprising a compound of one of formula I admixed with a pharmaceutically acceptable diluent, carrier, or excipient. What is also provided is a method of treating a bacterial infection in a mammal, comprising administering to a mammal in need thereof an effective amount of a compound of formula I. DETAI ED DESCRIPTION Reference will now be made in detail to presently preferred compositions or embodiments and methods of the invention, which constitute the best modes of practicing the invention presently known to the inventors. The term "alkyl" as used herein refers to a straight or branched hydrocarbon of from 1 to 6 carbon atoms and includes, for example, methyl, ethyl, n-propyl, isopropyl, n- butyl, sec-butyl, isobutyl, ferf-butyl, n-pentyl, n-hexyl, and the like. The alkyl group can also be substituted with one or more of the substituents selected from lower (C-_| - C₆)alkoxy, (C-|-C₆)thioalkoxy, halogen, oxo, thio, -OH, -SH, -F, -CF_3>- OCF₃, -NO₂, -

^"

C0₂H, -CO₂(C-_|-C₆)alkyl, or — O . The term "(C₃-C₆)cycloalkyl" means a hydrocarbon ring containing from 3 to 6 carbon atoms, for example, cyclopropyl, cyclobutyl, cyclopentyl, or cyclohexyl. Where possible, the cycloalkyl group may contain double bonds, for example, 3-cyclohexen-1 - yl. The cycloalkyl ring may be unsubstituted or substituted by one or more substituents selected from alkyl, alkoxy, thioalkoxy, hydroxy, thiol, halogen, formyl, carboxyl, - Cθ2(C-_| -Cg)alkyl, -CO(Cι-C-6)alkyl, aryl, heteroaryl, wherein alkyl, aryl, and heteroaryl are as defined herein, or as indicated above for alkyl. Examples of substituted cycloalkyl groups include fluorocyclopropyl. The term "halo" includes chlorine, fluorine, bromine, and iodine. The term "aryl" means a cyclic or polycyclic aromatic ring having from 5 to 12 carbon atoms, and being unsubstituted or substituted with one or moreof the substituent groups recited above for alkyl groups.including, halogen, nitro, cyano -OH, -SH, -F, -

not limited to phenyl, 2-chlorophenyl, 3-chlorophenyl, 4-chlorophenyl, 2-methylphenyl, 3- methylphenyl, 4-methylphenyl, 2-methoxyphenyl, 3-methoxyphenyl, 4-methoxyphenyl, 2- chloro-3-methylphenyl, 2-chloro-4-methylphenyl, 2-chloro-5-methylphenyl, 3-chloro-2- methylphenyl, 3-chloro-4-methylphenyl, 4-chloro-2-methylphenyl, 4-chloro-3- methylphenyl, 5-chloro-2-methylphenyl, 2,3-dichlorophenyl, 2,5-dichlorophenyl, 3,4- dichlorophenyl, 2,3-dimethylphenyl, 3,4-dimethylphenyl, naphthyl, 4-thionaphthyl, tetralinyl, anthracinyl, phenanthrenyl, benzonaphthenyl, fluorenyl, 2-acetamidofluoren-9- yl, and 4'-bromobiphenyl. The term "heteroaryl" means an aromatic cyclic or polycyclic ring system having from 1 to 4 heteroatoms selected from N, O, and S. Typical heteroaryl groups include 2- or 3-thienyl, 2- or 3-furanyl, 2- or 3-pyrrolyl, 2-, 4-, or 5-imidazolyl, 3-, 4-, or 5- pyrazolyl, 2-, 4-, or 5-thiazolyl, 3-, 4-, or 5-isothiazolyl, 2-, 4-, or 5-oxazolyl, 3-, 4-, or 5- isoxazolyl, 3- or 5-1 ,2,4-triazolyl, 4- or 5-1 ,2,3-triazolyl, tetrazolyl, 2-, 3-, or 4-pyridinyl, 3-, 4-, or 5-pyridazinyl, 2-pyrazinyl, 2-, 4-, or 5-pyrimidinyl, 2-, 3-, 4-, 5-, 6-, 7-, or 8- quinolinyl, 1-, 3-, 4-, 5-, 6-, 7-, or 8-isoquinolinyl, 2-, 3-, 4-, 5-, 6-, or 7-indolyl, 2-, 3-, 4-, 5-, 6-, or 7-benzo[t»]thienyl, 2-, 4-, 5-, 6-, or 7-benzoxazolyl, 2-, 4-, 5-, 6-, or 7- benzimidazolyl, 2-, 4-, 5-, 6-, or 7-benzothiazolyl. The heteroaryl groups may be unsubstituted or substituted by 1 to 3 substituents selected from those described above for alkyl, alkenyl, and alkynyl, for example, cyanothienyl and formylpyrrolyl. Preferred aromatic fused heterocyclic rings of from 8 to 10 atoms include but are not limited to 2-, 3-, 4-, 5-, 6-, 7-, or 8-quinolinyl, 1-, 3-, 4-, 5-, 6-, 7-, or 8-isoquinolinyl-, 2-, 3-, 4-, 5-, 6-, or 7-indolyl, 2-, 3-, 4-, 5-, 6-, or 7-benzo[t>]thienyl, 2-, 4-, 5-, 6-, or 7-benzoxazolyl, 2-, 4-, 5-, 6-, or 7-benzimidazolyl, 2-, 4-, 5-, 6-, or 7-benzothiazolyl. Heteroaryl also includes 2- and 3- aminomethylfuran, 2- and 3- aminomethylthiophene and the like.. The term "heterocyclic" means a monocyclic, fused, bridged, or spiro bicyciic heterocyclic ring systems. Monocyclic heterocyclic rings contain from about 3 to 12 ring atoms, with from 1 to 5 heteroatoms selected from N, O, and S, and preferably from 3 to 7 member atoms, in the ring. Bicyciic heterocyclics contain from about 5 to about 17 ring atoms, preferably from 5 to 12 ring atoms. Bicyciic heterocyclic rings may be fused, spiro, or bridged ring systems. Examples of heterocyclic groups include cyclic ethers (oxiranes) such as ethyleneoxide, tetrahydrofuran, dioxane, and substituted cyclic ethers, wherein the substituents are those described above for the alkyl and cycloalkyl groups. Typical substituted cyclic ethers include propyleneoxide, phenyloxirane (styrene oxide), cis-2-butene-oxide (2,3-dimethyloxirane), 3-chlorotetrahydrofuran, 2,6-dimethyl- 1 ,4-dioxane, and the like. Heterocycles containing nitrogen are groups such as pyrrolidine, piperidine, piperazine, tetrahydrotriazine, tetrahydropyrazole, and substituted groups such as 3-aminopyrrolidine, 4-methylpiperazin-l-yl, and the like. Typical sulfur containing heterocycles include tetrahydrothiophene, dihydro-1 ,3-dithiol-2-yl, and hexahydrothiophen-4-yl and substituted groups such as aminomethyl thiophene. Other commonly employed heterocycles include dihydro-oxathiol-4-yl, dihydro-1 H-isoindole, tetrahydro-oxazolyl, tetrahydro-oxadiazolyl, tetrahydrodioxazolyl, tetrahydrooxathiazolyl, hexahydrotriazinyl, tetrahydro-oxazinyl, morpholinyl, thiomorpholinyl, tetrahydropyrimidinyl, dioxolinyl, octahydrobenzofuranyl, octahydrobenzimidazolyl, and octahydrobenzothiazolyl. For heterocycles containing sulfur, the oxidized sulfur heterocycles containing SO or S0₂ groups are also included. Examples include the sulfoxide and sulfone forms of tetrahydrothiophene. When a bond is represented by a symbol such as " " this is meant to represent that the bond may be absent or present provided that the resultant compound is stable and of satisfactory valency. When a bond is represented by a line such as " "w ^ " this is meant to represent that the bond is the point of attachment between two molecular subunits. The term "patient" means all mammals, including humans. Other examples of patients include cows, dogs, cats, goats, sheep, pigs, and rabbits. A "therapeutically effective amount" is an amount of a compound of the present invention that, when administered to a patient, provides the desired effect; i.e., lessening in the severity of the symptoms associated with a bacterial infection. It will be appreciated by those skilled in the art that compounds of the invention having one or more chiral centers may exist in and be isolated in optically active and racemic forms. Some compounds may exhibit polymorphism. It is to be understood that the present invention encompasses any racemic, optically-active, polymorphic, geometric, or stereoisomeric form, or mixtures thereof, of a compound of the invention, which possess the useful properties described herein, it being well known in the art how to prepare optically active forms (for example, by resolution of the racemic form by recrystallization techniques, by synthesis from optically-active starting materials, by chiral synthesis, or by chromatographic separation using a chiral stationary phase) and how to determine activity or cytotoxicity using the standard tests described herein, or using other similar tests which are well known in the art. Certain compounds of Formula I are also useful as intermediates for preparing other compounds of Formula I. Thus, a compound wherein R₂ is NR₂, can be metabolized to form another compound of the invention wherein R₂ is H. This conversion can occur under physiological conditions. To that end, both the non- metabolized compound of the invention and the metabolized compound of the invention—that is, the compound wherein R₂ is NR₂ and the compound wherein R₂ is H — can have antibacterial activity. Some of the compounds of Formula I are capable of further forming pharmaceutically acceptable acid-addition and/or base salts. All of these forms are within the scope of the present invention. Thus, pharmaceutically acceptable acid addition salts of the compounds of Formula I include salts derived from nontoxic inorganic acids such as hydrochloric, nitric, phosphoric, sulfuric, hydrobromic, hydriodic, hydrofluoric, phosphorous, and the like, as well as the salts derived from nontoxic organic acids, such as aliphatic mono- and dicarboxylic acids, phenyl-substituted alkanoic acids, hydroxy alkanoic acids, alkanedioic acids, aromatic acids, aliphatic and aromatic sulfonic acids, etc. Such salts thus include sulfate, pyrosulfate, bisulfate, sulfite, bisulfite, nitrate, phosphate, monohydrogenphosphate, dihydrogenphosphate, metaphosphate, pyrophosphate, acetate, trifluoroacetate, propionate, caprylate, isobutyrate, oxalate, malonate, succinates suberate, sebacate, fumarate, maleate, mandelate, benzoate, chlorobenzoate, methylbenzoate, dinitrobenzoate, phthalate, benzensoulfonate, toluenesulfonate, phenylacetate, citrate, lactate, maleate, tartrate, methanesulfonate, and the like. Also contemplated are salts of amino acids such as arginate and the like and gluconate, galacturonate (see, for example, Berge, S.M. et. al., "Pharmaceutical Salts," Journal of Pharmaceutical Science, 1977;66:1-19). The acid addition salt of said basic compounds are prepared by contacting the free base form with a sufficient amount of the desired acid to produce the salt in the conventional manner. Pharmaceutically acceptable base addition salts are formed with metals or amines, such as alkali and alkaline earth metals or organic amines. Examples of metals used as cations are sodium, potassium, magnesium, calcium, and the like. Examples of suitable amines are N,N'-dibenzylethylenediamine, chloroprocaine, choline, diethanolamine, dicyclohexylamine, ethylenediamine, N-methylglucamine, and procaine (see, for example, Berge S.M., supra., 1977). The base addition salts of said acidic compounds are prepared by contacting the free acid form with a sufficient amount of the desired base to produce the salt in the conventional manner. Certain of the compounds of the present invention can exist in unsolvated forms as well as solvated forms, including hydrated forms. In general, the solvated forms, including hydrated forms, are equivalent to unsolvated forms and are intended to be encompassed within the scope of the present invention. A "prodrug" is an inactive derivative of a drug molecule that requires a chemical or an enzymatic biotransformation in order to release the active parent drug in the body. Specific and preferred values for the compounds of the present invention are listed below for radicals, substituents, and ranges are for illustration purposes only, and they do not exclude other defined values or other values within defined ranges for the radicals and substituents. Thus, we turn now to a compound of formula I, which has the structure:

In one embodiment of a compound of formula I , RT is (C C₆)alkyl, halo(C₁-C₆)alkyl, (C₃-C₆)cycloalkyl, halo(C₃-C₆)cycloalkyl aryl, and heteroaryl; R₂ is OH, O(C_rC₆)aikyl, O(C₃-C₆)cycloalkyl, O 0-(CHR₂a)m~0 QR₂b , wherein m is an integer of from 1 to 10, Q is O or is absent, and R_2a is H or (CrC₆)alkyl and R_2b is (C C₆)alkyl, aryl, or heteroaryl, O— (CHR2a)n^—Y _t wherein R_2a is as defined above, n is an integer of from 2 to 10, Y is OH or NR_2oR_2d. wherein R_2c and R_2cι are each independently H, (Cι-C₆)alkyl, or (C₃-C₆)cycloalkyl, or NR_2d, wherein R_2cι is as defined above,

" indicates the point of attachment, 2a is as defined above, R_2e is H or (CτC₆)alkyl, e is an integer of from 1 to 10, p is an integer of from 2 to 10, and X^ and Yi are each independently NH or O; R₃, R₄, and R₅ are each independently H, halo, NH₂, (Cι-Cβ)alkyl, halo(C C₆)alkyl, (CrC₆)alkoxy, or halo(CrC₆)alkoxy. In another embodiment, compounds of formula I have the following core

Table 6

Table 6

Table 6

More particularly, compounds of the invention have the following core structures

in Table 7, wherein A' is

Table 7

Table 7

Table 7

Table 8

Preparation of Compounds Strategies for the preparation of invention compounds are depicted in in the following Schemes. As is readily apparent from this disclosure, compounds of the present invention are characterized by a quinolone core, covalently bound to a pyrollidinyl C-7 group bearing an oxazol-2-yl-methylamine sidechain. As is retrosynthetically depicted in Scheme I, the invention compounds can be prepared via coupling of a suitably C-7 substituted quinolone core precursor, wherein X is halo, triflate, or a similar reactive group known to the skilled artisan, and an appropriately substituted pyrollidine. Scheme I

X= halo, OS0₂CF₃, R= H, (C_rC₆)alkyl, BF₂ Reflecting the synthetic strategy summarized in Scheme I, the following section describing the preparation of the invention compounds has several parts. The first part describes the synthesis of the requisite quinolone core precursors. The second part describes the synthesis of the requisite C-7 sidechain precursors. The final part describes the coupling of the C-7 sidechain and quinolone core precursors to provide the invention compounds, and details any further chemical elaboration of invention compounds to produce other invention compounds. A. Synthesis of Aminoquinazolinedione Core Precurors The quinolone core precursors that are used to prepare the invention compounds are generally known to the skilled artisan and can be commercially obtained, or alternatively, can be prepared using routine synthetic methods. The following sections provide relevant citations that describe the preparation of the quinolone core precursors used to practice the invention disclosed herein or as otherwise indicated.

1. Preparation of Quinolone Core Precursors

. Preparation of Quinolone Core Precursors

Preparation of

Preparation of

B. Synthesis of C-7 Sidechain Precurors

A general approach to the preparation of pyrollidines bearing an oxazol-2-yl- methylamine sidechain that are useful to practice the invention is depicted in Scheme II. Thus, compound 1 is treated with methanesulfonyl chloride ("mesyl chloride) or an alternative such as tosyl chloride in the presence of an amine base such as triethylamine (TEA") to provide mesylate 2. Nucleophilic displacement of the mesylate in DMF using a ammonia or a primary or secondary amine as the nucleophile provides compound 3. If the amine moiety in compound 3 is a tertiary amine, hydrogenation in step 3a provides compound 4. If the amine moiety in compound 3 is a primary or secondary amine, protection in step 3b, followed by hydrogenation in step 4 provides the requisite compound. Scheme II

Specific variants of the Scheme II approach are depicted in Schemes III and IV.

Thus, mesylation of 3-(hydroxy-oxazol-2-yl-methyl)-pyrrolidine-1-carboxylic acid benzyl ester 1 in the presence of triethylamine provided 3-(methane sulfonyloxy-oxazol-2-yl- methyl)-pyrrolidine-1 -carboxylic acid benzyl ester 2 in 80 percent yield. Treatment of 3- (methanesulfonyloxy-oxazol-2-yl-methyl)-pyrrolidine-1-carboxylic acid benzyl ester with methylaminein the presence of DMF provided 3-(methylamino-oxazol-2-yl-methyl)- pyrrolidine-1 -carboxylic acid benzyl ester 3 in 90 percent yield. Although methylamine was used as the amine in step 2 of Scheme III, other amines were used as well, such as ammonia, ethylamine, and isopropyl amine. The product of step 2 was Boc-protected, and then hydrogentated to provide Methyl-(oxazol-2-yl-pyrrolidin-3-yl-methyl)-carbamic acid tert-butyl ester in 82 percent yield. Scheme III

In Scheme IV, dimethylamine was used as the amine in step 2 to provide 3- (dimethylamino-oxazol-2-yl-methyl)-pyrrolidine-1 -carboxylic acid benzyl ester as a mixture of isomers in 51 percent yield. Hydrogenation of 3-(dimethylamino-oxazol-2-yl- methyl)-pyrrolidine-1 -carboxylic acid benzyl ester provided the target compound. Scheme IV

e

3a (Isomer A) 3b (Isomer A and B) C. Coupling of

and Quinolone Core Precurors to Provide Invention Compounds Coupling of the sidechain precursor to the quinolone core precursor to provide the compounds of the present invention can occur from either the core precursor as the free acid, alkyl ester, or borate ester, as depictedin Scheme C-1. Scheme V

X= halo, OS0₂CF₃

Typically, when a free acid is used in the coupling reaction, a molar excess of the side chain precursor is combined with the quinolone core in a polar solvent such as acetonitrile (6 mL). A molar excess of an amine base such as triethylamine is added, and the reaction mixture is heated to about 80 °C. Typically, the reaction mixtures become homogenous. The mixture is heated for sufficient time to drive the reaction to completion, typically from about 3 to about 12 hours. The mixture is then worked up according to procedures widely used by the skilled artisan to provide a compound of the invention. When an alkyl ester is used in the coupling reaction, the quinolone core, sidechain, and triethylamine are combined in a solvent such as acetonitrile. The resulting reaction mixture is heated to 80 ^BC and stirred for 12 hours, is heated to about 80 °C. Typically, the reaction mixtures becomes homogenous. The mixture is heated for sufficient time to drive the raction to completion, typically from about 3 to about 12 hours. The mixture is then worked up according to procedures widely used by the skilled artisan to provide a compound of the invention. When a borate ester is used in the coupling reaction, the requisite borate ester is typically prepared from the free acid upon reaction with BF₃ according to conditions available to the skilled artisan. Theborater ester is typically combined with the side chain in a solvent such as acetonitrile and treated with an amine base such as triethylamine. The resulting reaction mixture is typically stirred at room temperature for sufficient time to drive the reaction to completion, typically from about 24 to about 96 hours. The mixture is then worked up according to procedures widely used by the skilled artisan to provide a compound of the invention. Pharmaceutical Formulations The present invention also provides pharmaceutical compositions which comprise a bioactive invention compound or a salt such or a pharmaceutically acceptable salt thereof and optionally a pharmaceutically acceptable carrier. The compositions include those in a form adapted for oral, topical or parenteral use and can be used for the treatment of bacterial infection in mammals including humans. The compounds, such as antibiotic compounds, also referred to herein as antimicrobial compounds, according to the invention can be formulated for administration in any convenient way for use in human or veterinary medicine, by analogy with other bioactive agents such as antibiotics. Such methods are known in the art and are not described in detail herein. The composition can be formulated for administration by any route known in the art, such as subdermal, by-inhalation, oral, topical or parenteral. The compositions may be in any form known in the art, including but not limited to tablets, capsules, powders, granules, lozenges, creams or liquid preparations, such as oral or sterile parenteral solutions or suspensions. The topical formulations of the present invention can be presented as, for instance, ointments, creams or lotions, eye ointments and eye or ear drops, impregnated dressings and aerosols, and may contain appropriate conventional additives such as preservatives, solvents to assist drug penetration and emollients in ointments and creams. The formulations may also contain compatible conventional carriers, such as cream or ointment bases and ethanol or oleyl alcohol for lotions. Such carriers may be present, for example, from about 1% up to about 98% of the formulation. For example, they may form up to about 80% of the formulation. Tablets and capsules for oral administration may be in unit dose presentation form, and may contain conventional excipients such as binding agents, for example syrup, acacia, gelatin, sorbitol, tragacanth, or polyvinylpyrollidone; fillers, for example lactose, sugar, maize-starch, calcium phosphate, sorbitol or glycine; tabletting lubricants, for example magnesium stearate, talc, polyethylene glycol or silica; disintegrants, for example potato starch; or acceptable wetting agents such as sodium lauryl sulphate. The tablets may be coated according to methods will known in normal pharmaceutical practice. Oral liquid preparations may be in the form of, for example, aqueous or oily suspensions, solutions, emulsions, syrups or elixirs, or may be presented as a dry product for reconstitution with water or other suitable vehicle before use. Such liquid preparations may contain conventional additives, such as suspending agents, for example sorbitol, methyl cellulose, glucose syrup, gelatin, hydroxyethyl cellulose, carboxymethyl cellulose, aluminium stearate gel or hydrogenated edible fats, emulsifying agents, for example lecithin, sorbitan monooleate, or acacia; non-aqueous vehicles (which may include edible oils), for example almond oil, oily esters such as glycerine, propylene glycol, or ethyl alcohol; preservatives, for example methyl or propyl p- hydroxybenzoate or sorbic acid, and, if desired, conventional flavoring or coloring agents. For parenteral administration, fluid unit dosage forms are prepared utilizing the compound and a sterile vehicle, water being preferred. The compound, depending on the vehicle and concentration used, can be either suspended or dissolved in the vehicle or other suitable solvent. In preparing solutions, the compound can be dissolved in water for injection and filter sterilized before filling into a suitable vial or ampoule and sealing. Advantageously, agents such as a local anesthetic preservative and buffering agents can be dissolved in the vehicle. To enhance the stability, the composition can be frozen after filling into the vial and the water removed under vacuum. The dry lyophilized powder is then sealed in the vial and an accompanying vial of water for injection may be supplied to reconstitute the liquid prior to use. Parenteral suspensions are prepared in substantially the same manner except that the compound is suspended in the vehicle instead of being dissolved and sterilization cannot be accomplished by filtration. The compound can be sterilized by exposure to ethylene oxide before suspending in the sterile vehicle. Advantageously, a surfactant or wetting agent is included in the composition to facilitate uniform distribution of the compound. The compositions may contain, for example, from about 0.1% by weight, e.g., from about 10-60% by weight, of the active material, depending on the method of administration. Where the compositions comprise dosage units, each unit will contain, for example, from about 50-500 mg of the active ingredient. The dosage as employed for adult human treatment will range, for example, from about 100 to 3000 mg per day, for instance 1500 mg per day depending on the route and frequency of administration. Such a dosage corresponds to about 1.5 to 50 mg/kg per day. Suitably the dosage is, for example, from about 5 to 20 mg/kg per day. Biological Activity The invention compounds can be screened to identify bioactive molecules with different biological activities using methods available in the art. The bioactive molecules, for example, can possess activity against a cellular target, including but not limited to enzymes and receptors, or a microorganism. A target cellular ligand or microorganism is one that is known or believed to be of importance in the etiology or progression of a disease. Examples of disease states for which compounds can be screened for biological activity include, but are not limited to, inflammation, infection, hypertension, central nervous system disorders, and cardiovascular disorders. In one embodiment, the invention provides methods of treating or preventing a bacterial infection in a subject, such as a human or other animal subject, comprising administering an effective amount of an invention compound as disclosed herein to the subject. In one embodiment, the compound is administered in a pharmaceutically acceptable form optionally in a pharmaceutically acceptable carrier. As used herein, an "infectious disorder" is any disorder characterized by the presence of a microbial infection, such as bacterial infections. Such infectious disorders include, for example central nervous system infections, external ear infections, infections of the middle ear, such as acute otitis media, infections of the cranial sinuses, eye infections, infections of the oral cavity, such as infections of the teeth, gums and mucosa, upper respiratory tract infections, lower respiratory tract infections, genitourinary infections, gastrointestinal infections, gynecological infections, septicemia, bone and joint infections, skin and skin structure infections, bacterial endocarditis, burns, antibacterial prophylaxis of surgery, and antibacterial prophylaxis in immunosuppressed patients, such as patients receiving cancer chemotherapy, or organ transplant patients. The compounds and compositions comprising the compounds can be administered by routes such as topically, locally or systemically. Systemic application includes any method of introducing the compound into the tissues of the body, e.g., intrathecal, epidural, intramuscular, transdermal, intravenous, intraperitoneal, subcutaneous, sublingual, rectal, and oral administration. The specific dosage of antimicrobial to be administered, as well as the duration of treatment, may be adjusted as needed. The compounds of the invention may be used for the treatment or prevention of infectious disorders caused by a variety of bacterial organisms. Examples include Gram positive and Gram negative aerobic and anaerobic bacteria, including Staphylococci, for example S. aureus; Enterococci, for example E. faecalis; Streptococci, for example S. pneumoniae; Haemophilus, for example H. influenza; Moraxella, for example M. catarrhalis; and Escherichia, for example E. coli. Other examples include Mycobacteria, for example M. tuberculosis; intercellular microbes, for example Chlamydia and Rickettsiae; and Mycoplasma, for example M. pneumoniae. The ability of a compound of the invention to inhibit bacterial growth, demonstrate in vivo activity, and enhanced pharmacokinetics are demonstrated using pharmacological models that are well known to the art, for example, using models such as the tests described below. Test A— Antibacterial Assays The compounds of the present invention were tested against an assortment of Gram-negative and Gram-positive organisms using standard microtitration techniques (Cohen et. al., Antimicrob., 1985;28:766; Heifetz, et. al., Antimicrob., 1974;6:124). The results of the evaluation are shown in Tables 9 and 10. Test B — Antibacterial Clonogenicity Assay (ABTC) The antibacterial clonogenicity assay (ABTC) is a cell proliferation assay developed to assess acute toxicity of chemical matter from antibacterial projects. Clonogenicity is the colony-forming ability of cultured mammalian cells. In the assay, adherent cells (V-79, Chinese hamster lung) are exposed to a compound at concentrations ranging from 500 to 7.8 μg/ml_ for 3 hours. The cells are then washed to remove residual compound and incubated in compound-free media for several days. The resulting colonies are counted and percent survival is calculated, which is used to determine the IC₅₀. Higher IC₅₀ values indicate reduced potential of acute toxicity to mammalian cells. The traditional format of the ABTC assay was developed using a volume of 3 mlJwell in 6 well tissue culture plates for colony growth and compound exposure, and used crystal violet to stain colonies for counting. Recent advances in technology have made it possible to scale down this assay to 100 μL/well in a 96-well plate while automating a majority of the assay. This required the implementation of new methods for liquid handling and cell viability determination. The result is a miniaturized version of the traditional assay which utilizes the Beckman Biomek FX for liquid handling and the Promega CellTiter-Glo Luminescent Cell Viability assay to determine the number of live cells remaining in each well after incubation. These changes have made it possible to dramatically increase the throughput of the assay while decreasing the amount of time, compound, and reagents required to perform the assay. Methods Cell Culture Materials and Methods V79 (Chinese hamster lung) cells were grown in Gibco RPMI Medium 1640 with 25 mM HEPES and L-glutamine + 10% Gibco fetal bovine serum (FBS). Incubation conditions were 37°C, 5% C0₂, humidified. Cell lines were maintained in Corning tissue culture (TC) treated 25-cm² flasks with 0.2-μm vented caps using the aforementioned media with the addition of 50 μg/mL Gibco Gentamicin. Gibco Hanks Balanced Salt Solution (without calcium chloride, magnesium sulfate, or magnesium chloride) was used to wash the cells. Cells were seeded into Costar Corning 3917 plates (96-well, white, flat-bottomed, TC-treated, sterile, with lid). The CellTiter-Glo cell viability assay by Promega was used in conjunction with the Wallac Victor2 plate reader. Adaptation of Cell Viability Assay to a 96-Well Luminescence Format V79 cells (1000 per well in 100 μL media) were seeded into Costar Corning 391796-well plates and incubated. After incubation periods ranging from 1 to 7 days, CellTiter-Glo reagent (100 μLΛ/vell) was added to each plate. The plates were shaken for 2 minutes, incubated at room temperature for 10 minutes, and then read on the Victor2 plate reader using the damped luminescence detection setting. Determination of Optimal Instrument Settings and Limits of Detection for the Wallac Victor2 Plate Reader Serial dilutions of cells in media (100 μL) ranging from 100,000 to 8 cells/well were prepared in a Costar Corning 3917 plate. A separate Costar Corning 3917 plate containing 200,000 cells in media (100 μL) dispensed only into Well A1 was also prepared. The plates were read on the Wallac Victor2 luminescence detection program. These plates were read at detector heights of 18, 14, 12, and 9 mm from the bottom of the plate using normal and damped aperture settings.

Optimization of Cell Washing Using the Bio-Tek Instruments ELx405 Plate Washer Six Costar Corning 3917 plates were seeded with 1000 cells/well in media (100 μL) and incubated at 37°C (5% C0₂, humidified) overnight. Four plates were washed with Hanks Balanced Salt Solution on the Bio-Tek Instruments ELx405 using programs with differing aspirate and dispense parameters. Control experiments included one unwashed plate and one plate in which media was manually removed with a Matrix multichannel pipette and new media was added with the same pipette. Four columns on each plate received CellTiter-Glo reagent and the plates were read on the Wallac Victor2. Optimization of Cell Outgrowth Time Ten identical Costar Coming 3917 plates were seeded with 1000 cells/well, incubated overnight, aspirated, and exposed to serial diluted compound in media at concentrations from 500 to 15.6 μg/mL for 3 hours. The plates were then washed with Hanks Balanced Salt Solution using the ELx405 plate washer, and new media was added and incubated from 1 to 6 days. Plates were read using the CellTiter-Glo assay on the Victor2 plate reader. Automation Using the Beckman Biomek FX Costar Corning 3917 plates were seeded with 1000 cells/well, incubated at 37°C (5% C0₂, humidified) overnight, then aspirated. Dimethyl sulfoxide (DMSO) stocks (25 mg/mL) of the compounds to be tested were prepared in Eppendorf amber microcentrifuge tubes or clear glass vials, then transferred in 100 μL aliquots to separate wells in column 1 of a Costar Corning 3799 96-well round-bottomed plate. The FX program is as follows: The following items are placed on the FX deck: Sterile Biomek P250 Span-8 Pipette Tips, sterile Biomek P250 Tip Rack Assemblies, DMSO reservoir (tip lid), aspirated cell plates, Costar Corning 3799 plate for serial dilution, Costar Corning 3799 plate for media precipitate check, and a Beckman deep well titer plate containing 490 μL media. Upon initiation of the Clono program, the Span-8 pod will load tips, aspirate 200 μL DMSO from the reservoir, dispense 50 μL DMSO into columns 2 to 5 of the serial dilution plate, aspirate 150 μL DMSO from the reservoir, dispense 50 μL DMSO into columns 6 to 8 of the serial dilution plate, and eject tips into waste. The Span-8 pod will then load tips, move to the serial dilution plate and mix Column 1 , aspirate 50 μL from Column 1 , dispense the liquid into Column 2, mix Column 2, and repeat the aspirate, dispense, and mix steps for the remaining columns through Column 7. The Span-8 pod will aspirate 50 μL from Column 7 and eject the tips and liquid into the waste. The 96-tip head will load tips, aspirate 10 μL from the serial dilution plate, dispense 10 μL into the media block, mix, unload tips, remove lids from cell plates, load new tips, aspirate 100 μL from the media block, dispense 100 μL into Cell Plate 1 , aspirate 100 μL from the media block, dispense 100 μL into Cell Plate 2, aspirate 100 μL from the media block, dispense 100 μL into media plate (for precipitate check), unload tips, and replace lids on cell plates. The serial dilution plate and the media plate are both read on the Molecular Devices Spectramax at 595 nm. The plates are incubated at 37°C (5% C0₂, humidified) for 3 hours, then washed with Hanks Balanced Salt Solution on the ELx405 using the Clono.wash program. Fresh RPM1 1640 medium with 10% FBS (100 μL/well) is added each well and the plates are returned to the incubator for 3 days. The plates are then read on the Wallac Victor2 using the CellTiter-Glo assay. Dispense volume and serial dilution accuracy of the FX program were tested as follows. The volumes for liquid dispensed in the transfer steps of the FX were determined using the Molecular Devices Spectramax. Serial dilutions of concentrated crystal violet were prepared using the FX program and the absorbance of the serial diluted dye was read at 595 nm on the Spectramax.

IC₅₀ values for Clinafloxacin, difluorociprofloxacin, and a selection of compounds previously tested in the traditional clonogenicity assay were determined using the FX method. Test for Compound Precipitation After completion of the FX program, the absorbance of original DMSO serial dilution plate and a plate of the final compound dilutions in media were read at 595 nm on the Molecular Devices Spectramax. Absorbance readings more than 3 times background were interpreted to indicate precipitation of test compound in DMSO and/or media. RESULTS Adaptation of Cell Viability Testing to a 96-Well Luminescence Format In the traditional format of the ABTC assay, Costar Corning (3516) 6-well TC plates are seeded with 150 cells/well in 3 mL media (Gibco RPMI Medium 1640 with 25 mM HEPES and L-glutamine + 10% Gibco FBS). After a 3-hour exposure to serial dilutions of compound, cells are incubated for 5 days to produce colonies large enough to be counted on an ARTEK Colony Counter after being stained with crystal violet. To adapt this assay to a 96-well plate, the culture volume needed to be reduced and the optimal cell seeding density determined. A new method for counting the remaining viable cells was also needed. The Promega CellTiter-Glo Luminescent Cell Viability assay utilizes the adenosine triphosphate (ATP) present in live cells in an oxygenation of luciferin catalyzed by firefly luciferase. This reaction generates a luminescent signal in which the intensity is proportional to the number of viable cells in the solution. The

Promega system was chosen over competitor's systems because it is a single reagent addition which both lyses the cells and initiates the luciferase reaction. The Promega CellTiter-Glo assay can detect cells spanning 6 orders of magnitude, however, plating density needed to be determined to allow adequate differentiation between wells that had been adversely affected by the presence of drug and those that had not. The recommended culture volume for the CellTiter-Glo luminescence detection assay is 100 μlJwell for 96-well plates.

Plates seeded with 1000 cells/well gave peak luminescent signal between 3 and 5 days of incubation after seeding while maintaining low background luminescence. Reading plates after 4 days of incubation (3 days post drug exposure) was determined to be optimal. Determination of Optimal Instrument Settings and Limits of Detection for the Wallac Victor2 Plate Reader The Wallac Victor2 plate reader was evaluated using serial dilutions of cells to determine linear response range, appropriate detection settings, and presence of cross-talk between wells. The detector height of 9 mm from the bottom of the well using a damped aperture gave a sufficient signal with the least cross-talk between wells. The results from the serial dilution plate using a detector height of 9 mm with damped luminescence were graphed versus the number of cells/well, for cell numbers between 4 and 250,000 cells/well. Optimization of Cell Washing Using the Bio-Tek Instruments ELx405 Plate Washer The Bio-Tek Instruments ELx405 plate washer was chosen for its availability, ability to be automated, and efficiency at aspirating and dispensing liquids in 96-well plates. After plates were washed and read on the Victor2, the relative light units (RLU) detected for reagent containing wells were averaged, and standard deviation and percent standard deviation of the average were calculated for each plate. The standard deviation and percent standard deviation of the average were used as a basis for selecting the wash program that disrupted the cells the least while leaving a minimal volume of wash buffer in the wells. The final programs prepared for the aspirate and wash steps use an aspirate height of 42 (5.33 mm), dispense height of 80 (10.16 mm), and dispense and aspirate rates of 1. Optimization of Cell Outgrowth Time The plates read on the third day after exposure to the test compounds produced IC-₅₀ values closest to those obtained from the traditional assay. The 3-day incubation post drug exposure allows adequate time for damaged cells to die while keeping the control wells from becoming confluent. Automation Using the Beckman Biomek FX To increase speed and accuracy of preparing serial dilutions of compounds, the addition of the serial dilutions to media, and the transfer of the media to 96-well plates, the Beckman Coulter Biomek FX was utilized. The FX is a multifunctional liquid handling instrument that can simultaneously utilize a 96-tip head and an 8-tip Span-8 pod to transfer liquids and move labware. The DMSO stock solutions of the test compounds were increased in concentration to 25 mg/mL to provide a lower, constant concentration of DMSO in the final media dilutions. This 25 mg/mL stock, when serial diluted in DMSO and transferred to media to give the proper concentrations of compound for the assay, provides a uniform DMSO concentration of 2%. Preparing serial dilutions on the FX necessitated investigation of a new control compound. The traditional control compound difluorociprofloxacin is prepared and serial diluted in a weak NaOH solution, while the majority of current test compounds are prepared and diluted in DMSO. For the control compound to be assayed on the same 96-well plate as the test compounds, it must be prepared and diluted in the same solvent. Difluorociprofloxacin is not soluble in DMSO at the concentration required for the assay. Clinafloxacin (PD 0127391-0002) was chosen because it is soluble in DMSO at the required 25 mg/mL, readily available, and is used as the standard control compound in the minimal inhibitory concentration assays. Tests of the dispense volume accuracy at 50 and 100 μL show that the FX is dispensing a slightly higher volume than expected. Serial dilution accuracy tests showed that the FX is accurately performing the 1 :1 serial dilutions. The IC₅₀ values obtained using the FX method were comparable to those produced in the traditional assay for Clinafloxacin, Difluorociprofloxacin, and other compounds tested. The particular lot of Clinafloxacin determined to be best suited for the assay was Lot 28 due to its higher solubility in DMSO than the other lots tested. Test for Compound Precipitation As a method of detecting compounds that have precipitated out in the DMSO serial dilutions and/or the media, a precipitate check was integrated into the assay. Wells with detectable precipitate show increased absorbance at 595 nm due to light scattering. This step eliminates the need to manually check the serial dilutions and media dilutions for small amounts of precipitate and allow end users of the data to be alerted to the presence of precipitate in the assay. Comparison of Clonogenicity Results With Other Measures of Toxicity The clonogenicity assay has been utilized by the Antibacterial therapeutic area as an indicator of acute toxicity in the presence of bacterial gyrase/topoisomerase inhibitors. The assay is biased towards detection of compounds that cause rapid irrevocable damage to the cell, such as DNA strand breakage or membrane disruption. If a compound is genotoxic by inhibition of human topoisomerase II, then results of the clonogenic, in vitro micronucleus, and topoisomerase enzyme inhibition should be consistent. To test this hypothesis, selected compounds that were tested in all 3 assays were compared. In each case, the assays showed similar rank orders of toxicity. This result demonstrates that the clonogenic assay can detect acute genotoxic responses to compounds. Test C — Dofetilide Binding Assay The purpose of this screen is to test compounds for binding to the dofetilide binding site in HEK-293 cells that contain the HERG channel. Plates were generally received as 10 milimolar stock in DMSO or as powder samples. Samples were then diluted in 50 milimolar Tris-HCI (pH 7.4 RT) containing 1.2 milimolar MgCI2 and 10 milimolar KCI to give a concentration of 100 micromolar in 10% DMSO. A second 1to 10 dilution in 10% DMSO was then done to give a 10 micromolar stock plate in 10% DMSO. Dilution schemes may be changed to accommodate plate format. 25 microliter of the stock plate is then added to an empty 96 well tissue culture plate. Twenty five microliters of [3H]-dofetilide (50 nanamolar stock, resulting in the final assay having 5 nanamolar [3H]-dofetilide) is then added. The assay was started with the addition of 200 uL of HEK- 293 cells containing the HERG channel. Incubation was at room temperature for 90 minutes. Separation was by filtration through Whatman GF/B filters treated with 0.3% PEI using a 96 well cell harvester (Tomtec Mach III). Nonspecific binding was determined with 10 uM dofetilide. Radioactivity retained on the filters was determined with scintillation spectrophotometry. Samples of interest may be further tested to determine Ki. Binding curves were fit using Xcell Fit software (ID Business Solutions Inc.Emeryville, CA). The normalized data were fit by nonweighted nonlinear regression to y = Bottom + (Top - Bottom) 1 + 10x - Log EC50 Control data was entered as 100%. The top of the curves was constrained to 100% and the bottom of the curves was constrained to zero. Upon dilution of the test article, the dilution was added to one well on each of three separate plates. Averaging the percent controls of each of the three wells generates a single inhibition curve. The Cheng-prussoff equation was then used to convert the IC50 to Ki. Tables 9 and 10 summarize the data. As indicated by the Tables, we surprisingly and unexpectedly found that the oxazole-containing quinolone invention compounds were less toxic, compared to the the corresponding thiazole-containing quinolone.

S. S. S. S. Dofetilide Dofetilide aureus pyogenes pneumoniae pneumoniae Clonogenicity Dofetilide inh @ 100 inh @ 2552 C-203 SP-2747 SP-3765 IC50 KI uM 300 uM Table 10 (ug/mL) (ug/mL) (ug/mL) (ug/mL) (ug/mL) (uM) (%) (%)

Cpd a

0.008 0.03 0.06 0.06 <7.8 115 22 53

Cpd b 42

0.015 0.06 0.13 0.13 <7.8 >100 27

Cpd c

0.13 0.13 0.5 0.5 269 >150 12 34

oo o oo v oo o o CM Λ

CM m CM o O

CM m CM CM O

TD D)

TD TD TD 3 Q- Q- α. Q. ϋ ϋ ϋ ϋ o n m r- co D CM - CM M m co

m oo CM o CD o

m O ω CD

co CD

T3 ^■σ 3 Q. Q. Q. Q. U ϋ ϋ ϋ O CM CM CM CO ^- T-

o

oo

CD CO O CD

^■o X3

Q. Q. ϋ ϋ The following examples are provided to illustrate but not limit the claimed invention.

EXAMPLE 1

To a solution of oxazole (2.0 g, 29 mmol) in tetrahydrofuran (30 mL) was added borane-tetrahydrofuran complex (32 mL of a 1M solution) dropwise at room temperature. The reaction mixture was cooled to -78 °C and tert-butyllithium (19mL of a 1.7M solution in hexanes) was added dropwise. After stirring for 30 minutes, a solution of the aldehydexx (2.0 g, 29 mmol) in tetrahydrofuran (5 mL) was added. The reaction mixture stirred at 78 °C for 5 h, then 5% HOAc in ethanol (180 mL) was added. The mixture warmed to room temperature overnight. The reaction mixture was poured into brine and extracted three times with ethyl acetate. The combined organic layers were dried over magnesium sulfate, filtered and concentrated. The crude residue was purified by flash column chromatography (40 to 100% ethyl acetate in hexanes) to afford 4.9 g of compound. MS (APCI+): m/z303 (M+H).

To a solution of the alcohol (4.9 g, 16 mmol) in dichloromethane (80 mL) at 0 °C was added triethylamine (2.9 mL, 21 mmol) followed by methanesulfonyl chloride (1.51 mL, 19.4 mmol). The solution was warmed to room temperature and stirred overnight. Dichloromethane was added and the solution was washed with saturated aqueous sodium chloride solution. The organic layer was dried over magnesium sulfate, filtered and concentrated. The crude oil was taken into the next step without futher purification. To a solution of the crude oil in DMF (80 mL) was added sodium azide (1 Og, 160 mmol). The mixture was heated to 80 °C and left overnight. The reaction mixture was poured into water and extracted with ethyl acetate. The organic layer was dried over magnesium sulfate, filtered and concentrated. The crude residue was purified by flash column chromatography (0 to 40% ethyl acetate in hexanes) to give 4.9g of azide as a clear, colorless oil. MS (APCI+): m/z 328

To a solution of azide (5.2 g, 16 mmol) in tetrahydrofuran (80 mL) was added triphenylphosphine (6.7 g, 26 mmol) and water (0.58 mL, 32 mmol). The reaction mixture stirred at room temperature overnight. Additional water (0.5 mL) was added and the reaction stirred for another 48 h. The mixture was concentrated, diluted with dichloromethane, dried over magnesium sulfate, filtered and concentrated. The crude product was taken into the next reaction without further purification. To a solution of crude amine in dichloromethane (80 mL) was added triethylamine (3.3 mL, 24 mmol) followed by di-t-butyl dicarbonate (5.2 g, 24 mmol). The reaction mixture stirred overnight. The mixture was diluted with dichloromethane and washed with 1 N HCI solution followed by saturated sodium bicarbonate solution. The organic layer was dried over magnesium sulfate, filtered, and concentrated. The crude residue was purified by flash column chromatography (0 to 50% ethyl acetate in hexanes) to afford 400 mg (6%) of oxazole. The acidic aqueous layer was basified with 1 N NaOH solution and extracted with dichloromethane. The organic layer was dried over magnesium sulfate, filtered and concentrated to give a crude oil. To a solution of the oil in dichloromethane (8 mL) was added was added triethylamine (0.3 mL, 2.4 mmol) followed by di-t-butyl dicarbonate (0.5 g, 2.4 mmol). The reaction mixture was heated to 40 °C and stirred overnight. The mixture was diluted with dichloromethane and washed with 1 HCI solution followed by saturated sodium bicarbonate solution. The organic layer was dried over magnesium sulfate, filtered, and concentrated. The crude residue was purified by flash column chromatography (0 to 50% ethyl acetate in hexanes) to afford an additional 500 mg (8%) of oxazole. MS (APCI+): m/z 402 (M+H).

To a solution of oxazole (0.50g, 1.24 mmol) in methanol (50 mL) was added 20% Pd/C (0.15 mg). The reaction vessel was pressurized to 50 psi for 18 h, filtered through celite and concentrated to afford 330 mg of oxazole. MS (APCI+): m/z 268 (M+H). Example 2

7b 8a Target (Isomer A) 8b Target (Isomer A: B=1: 10)

Step 1 : To a solution of compound 1 (9.32 g, 30.8 mmol) (supplied by Ann Arbor) in dichloromethane (150 ml) at 0 °C, was added TEA (4.06 g, 5.6 ml, 40.1 mmol) followed by methanesulfonylchloride (4.24 g, 37.0 mmol). After stirring at RT for 18 h, the solution was diluted with dichloromethane (100 ml) and washed with brine. The solution was then dried (Na₂SO₄) and concentrated under reduced pressure. The crude product was further purified by column chromatography [hexanes - EtOAc/hexanes (60:40)] to give compound 2 (9.39 g). (TLC stained with PMA) ¹H NMR δ [(CD₃)₂SO] 8.23 (m, 1 H), 7.38 (m, 5H), 7.33 (m, 1 H), 5.80 (d, J=7.9 Hz, 0.7H), 5.79 (d, J=7.9 Hz, 0.3H), 5.08 (s, 1.4H), 5.07 (s, 0.6H), 3.55 (m, 1 H), 3.30 (m, 3H), 3.11 (m, 3H), 2.94 (m, 1 H), 1.86 (m, 1 H), 1.68

(m, 1 H). LCMS (APCI⁺) 381.

Step 2: Compound 2 (1.76 g, 4.6 mmol) was dissolved in 40 ml DMF. Dimethylamine (40% aq. soln, 5.21 g, 5.9 ml, 46.2 mmol) was added and the solution sealed in a bomb and heated to 70 °C for 2 h. While still sealed in the bomb, the solution was allowed to cool to RT overnight. The solution was then poured into water (100 ml) and extracted with EtOAc. The combined organic extracts were washed with brine x 4, dried (Na₂S0₄) and concentrated under reduced pressure. The crude product was purified by column chromatography [EtOAc/hexanes (40:60) - EtOAc/hexanes (50:50)] to give compound 3a (isomer A, at highest R_f by TLC) (0.34 g) and compound 3b (a mixture of isomers A and B) (0.44 g). (TLC stained with PMA) ¹H NMR 3a δ [(CD₃)₂SO] 8.09 (s, 1 H), 7.33 (m,

5H), 7.20 (s, 1H), 5.05 (m, 2H), 3.60-3.09 (m, 6H), 2.76 (m, 1 H), 2.13 (d, J=9.1 Hz, 6H), 1.78-1.23 (m, 1 H). LCMS (APCl⁺) 330.

¹H NMR 3b δ [(CD₃)₂SO] 8.09 (s, 0.6H), 8.08 (s, 0.4H), 7.31 (m, 5H), 7.20 (s, 0.6H), 7.19 (s, 0.4H), 5.04 (m, 2H), 3.60-3.09 (m, 6H), 2.76 (m, 1H), 2.15 (s, 6H), 1.78-1.23 (m, 1H). LCMS (APCI⁺) 330.

General Procedure Step 3: Compound 3a (0.34 g, 1.0 mmol) was dissolved in MeOH (20 ml). A catalytic amount of 10% Pd/C was added and the mixture was hydrogenated at 40 psi for 1.5 h. The catalyst was removed by filtration and the solution was concentrated to give compound 4a (0.20 g) ¹H NMR δ [(CD₃)₂SO] 8.01 (s, 1H), 7.15 (s, 1 H), 3.53-2.94 (m, 3H), 2.71 (m, 4H), 2.09 (m, 6H), 1.58 (m, 1 H), 1.09 (m, 1 H). LCMS

(APCI⁺) 196. Compound 3b was prepared in a similar manner and taken onto step 4 without further purification.

Step 4: To a solution of compound 5 (3.01 g, 9.3 mmol) in anhydrous THF (40 ml), was added boron trifluoroetherate (19.76g, 17.6 ml, 139.2 mmol). The solution was heated at 70 °C for 18 h. A precipitate formed. The solution was allowed to cool partially before diethyl ether (30 ml) was added. The solution was then allowed to cool further to RT. The precipitate was collected by filtration, washed with diethyl ether and dried under reduced pressure at 45 °C for 2 h, giving compound 6 (1.73 g). ¹H NMR δ [(CD₃)₂SO] 9.18 (s, 1H), 8.26 (dd, J=9.7, 8.2 Hz, 1H), 4.52 (m, 1H), 4.18 (d, J=2.2 Hz, 3H), 1.32 (m, 4H). LCMS (APCI⁺) 344.

General Procedure Step 5: To a solution of compound 4b (0.27 g, 1. 3 mmol) in acetonitrile (15 ml) was added TEA (0.18 g, 0.25 ml, 1.8 mmol) and compound 6 (0.31 g, 0.9 mmol). The solution was stirred at RT for 18 h. Dichloromethane (50 ml) was added to the solution and it was subsequently washed with NaHCO₃ then brine (x 2), dried (Na₂SO₄) and concentrated to give the crude product. The crude product was further purified by column chromatography [dichloromethane - MeOH/dichloromethane (2:98)] affording compound 7b as a foam (0.35 g). ¹H NMR δ [(CD₃)₂SO] 8.97 (s, 0.2H), 8.95 (s, 0.8H), 8.13 (d, J=0.7, 0.2H), 8.11 (d, J=0.7 Hz, 0.8H), 7.82 (d, J=13.9 Hz, 0.2H), 7.78 (d,

J=13.9 Hz, 0.8H), 7.25 (d, J=0.7 Hz, 0.2H), 7.22 (d, J=0.7 Hz, 0.8H), 4.33 (m, 1 H), 3.87- 3.56 (m, 5H), 3.55 (s, 3H), 3.00 (m, 1 H), 2.21 (s, 4.8H), 2.20 (s, 1.2H), 1.98-1.48 (m, 2H), 1.18 (m, 2H), 1.04 (m, 2H). LCMS (APCI⁺) 519. Compound 7a was prepared in a similar manner (0.24 g). ¹H NMR δ [(CD₃)₂SO] 8.97 (s, 1 H), 8.14 (d, J=0.6, 1 H), 7.82 (d, J=13.9 Hz, 1 H), 7.25 (d, J=0.6 Hz, 1 H), 4.37 (m,

1 H), 3.88-3.55 (m, 5H), 3.57 (s, 3H), 3.00 (m, 1 H), 2.20 (s, 6H), 1.83 (m, 1 H), 1.54 (m, 1 H), 1.27 (m, 2H), 1.07 (m, 2H). LCMS (APCI^") 519.

General Procedure Step 6: Compound 7a (0.23 g, 0.45 mmol) was dissolved in a mixture of EtOH (20ml) and dioxane (20 ml). TEA (0.23 g, 0.3 ml, 2.2 mmol) was added and the solution was refluxed for 2 h. The reaction had gone to completion by LCMS.

The solution was allowed to cool and the solvent removed under reduced pressure. The residue was dried under high vacuum for 2h to remove excess TEA. The residue was then dissolved in MeOH and sufficient methanolic HCI added to ensure an acidic solution. A minimal amount of EtOAc was added to induce crystallization. The required compound 8a (0.12 g) was collected by filtration and washed with EtOAc then diethyl ether, m.p.

239-242 °C. ¹H NMR δ [(CD₃)₂SO] 15.10 (v br s, 1 H), 10.65 (v br s, 1 H), 8.67 (s, 1 H), 8.34 (s, 1 H), 7.70 (d, J=13.8 Hz, 1 H), 7.45 (s, 1 H), 4.97 (v br s, 1 H), 4.14 (m, 1 H), 3.77 (m, 3H), 3.57 (s, 3H), 3.44 (m, 1 H), 3.15 (m, 1 H), 2.73 (br s, 6H), 1.79 (m, 1 H), 1.60 (m, 1 H), 1.11 (m, 3H), 0.91 (m, 1 H). LCMS (APCI⁺) 471. HPLC 99.2 % (297 nm). Anal. Calcd for C₂₄H₂₈CIFN₄O₅.0.75(H₂O) : C, 55.4; H, 5.7; N, 10.8; Cl, 6.8. Found C, 55.4; H, 5.5; N,

10.7; Cl, 6.6. Compound 8b was prepared in a similar manner (0.21 g). m.p. 199-202 °C. ¹H NMR δ [(CD₃)₂SO] 15.10 (v br s, 1 H), 10.70 (v br s, 1 H), 8.67 (s, 0.1 H), 8.65 (s, 0.9H), 8.34 (s, 1 H), 7.70 (d, J=13.8 Hz, 0.1 H), 7.66 (d, J=13.8 Hz, 0.9H), 7.45 (s, 1 H), 5.10 (v br s, 1 H), 4.12 (m, 1 H), 3.84-3.57 (m, 3H), 3.54 (s, 3H), 3.32 (m, 1 H), 3.19 (m, 1 H), 2.78 (br s, 6H), 2.34 (m, 1 H), 1.91 (m, 1 H), 1.16 (m, 1 H), 1.05 (m, 1 H), 0.92 (m, 2H). Anal. Calcd for C₂₄H₂₈CIFN₄O₅.1.2(H₂O) : C, 54.5; H, 5.8; N, 10.6. Found C, 54.4; H, 5.6; N, 10.4. Example 3

1) TEA / reflux EtOH/dioxane 2) HCI(g)/dioxane

7a (Isomer B) ^steP ⁶ _{8g τ} 7b (Isomer A:B=4:1) (Isomer B) 8b Target (Isomer A:B=4:1) Step 1 : To a solution of compound 1 (9.32 g, 30.8 mmol) (supplied by Ann Arbor) in dichloromethane (150 ml) at 0 °C, was added TEA (4.06 g, 5.6 ml, 40.1 mmol) followed by methanesulfonylchloride (4.24 g, 37.0 mmol). After stirring at RT for 18 h, the solution was diluted with dichloromethane (100 ml) and washed with brine. The solution was then dried (Na₂SO ) and concentrated under reduced pressure. The crude product was further purified by column chromatography [hexanes - EtOAc/hexanes (60:40)] to give compound 2 (9.39 g). (TLC stained with PMA) H NMR δ [(CD₃)₂SO] 8.23 (m, 1 H), 7.38 (m, 5H), 7.33 (m, 1 H), 5.80 (d, J=7.9 Hz, 0.7H), 5.79 (d, J=7.9 Hz, 0.3H), 5.08 (s, 1.4H),

5.07 (s, 0.6H), 3.55 (m, 1 H), 3.30 (m, 3H), 3.11 (m, 3H), 2.94 (m, 1 H), 1.86 (m, 1 H), 1.68 (m, 1 H). LCMS (APCI⁺) 381. Step 2: Compound 2 (1.64 g, 4.3 mmol) was dissolved in 40 ml DMF. Methylamine (40% aq. soln, 4.51 g, 5.0 ml, 58.1 mmol) was added and the solution sealed in a bomb and heated to 70 °C for 2 h. The solution was allowed to cool, then poured into water (100 ml) and extracted with EtOAc. The combined organic extracts were washed with brine x 4, dried (Na₂S0₄) and concentrated under reduced pressure. Crude compound 3 (1.21 g) was taken onto the next step without further purification. LCMS (APC1⁺) 316. Step 3: Di-ferf-butyl dicarbonate (1.26 g, 5.8 mmol) was added to a solution of crude compound 3 (1.21 g, 3.8 mmol) in dichloromethane (20 ml) and TEA (0.58 g, 0.8 ml, 5.8 mmol). The solution was left to stir at RT for 18 h. Dichloromethane (100 ml) was added and the organic solution was washed with 1 M HCI follwed by a sat. NaHC0₃ soln. The organic layer was dried (Na₂S0₄) and concentrated to give a crude residue that was further purified by column chromatography [EtOAc/hexane (10:90) -EtOAc/hexane

(50:50)], giving compound 4 (0.47 g). ¹H NMR δ [(CD₃)₂SO] 8.11 (s, 0.6H), 8.10 (s, 0.4H), 7.33 (m, 5H), 7.22 (s, 0.6H), 7.20 (s, 0.4H), 5.25-4.99 (m, 1 H), 5.06 (s, 1.2H), 5.05 (s, 0.8H), 3.62 (m, 1 H), 3.45 (m, 1 H), 3.02 (m, 2H), 2.64 (br s, 3H), 1.98 (m, 1 H), 1.66 (m, 1 H), 1.40 (m, 9H), 1 H obscured by water peak. LCMS (APCI⁺) 416. Step 4: Compound 4 (0.47 g, 1.1 mmol) was dissolved in MeOH (50 ml). A catalytic amount of 10% Pd/C was added and the mixture was hydrogenated at 40 psi for 2 h. The catalyst was removed by filtration and the solution was concentrated to give compound 5 (0.26 g). ¹H NMR δ [(CD₃)₂SO] 8.07 (s, 1 H), 7.19 (s, 1 H), 5.14-4.90 (m, 1 H), 2.83 (m, 4H), 2.65 (s, 1.5H), 2.64 (s, 1.5H), 2.38 (m, 1 H), 1.78 (m, 1 H), 1.40 (m, 10H), 1.24 (m, 1 H). LCMS (APCI⁺) 282. Step 5: To a mixture of compound 5 (0.26 g, 0. 9 mmol) in acetonitrile (3 ml) was added TEA (0.13 g, 0.17 ml, 1.2 mmol) and compound 6 (0.21 g, 0.6 mmol). The reaction mixture was stirred overnight and a precipitate collected by filtration to give compound 7a (0.13 g) (diastereoisomer B, at lowest R, by TLC). ¹H NMR δ [(CD₃)₂SO] 8.97 (s, 1 H), 8.14 (d, J=0.6 Hz, 1 H), 7.83 (d, J=13.8 Hz, 1 H), 7.27 (d, J=0.6 Hz, 1 H), 5.42 (br s, 0.5H),

5.18 (br s, 0.5H), 4.36 (br s, 1 H), 3.92-3.72 (m, 3H), 3.64 (m, 1 H), 3.60 (s, 3H), 3.16 (m, 1 H), 2.68 (s, 3H), 2.20 (m, 1 H), 1.78 (m, 1 H), 1.39 (br s, 9H), 1.26-1.07 (m, 4H). The filtrate was concentrated in vacua and chromatography of the residue on Si0₂ eluting with 2% MeOH/CH₂CI₂gave compound 7b (0.18 g) (diastereoisomer A:B = 4:1). ¹H NMR δ [(CD₃)₂SO] 8.97 (s, 0.2H), 8.96 (s, 0.8H), 8.14 (d, J=0.6 Hz, 0.2H), 8.13 (d, J=0.6 Hz, 0.8H), 7.83 (d, J=13.8 Hz, 0.2H), 7.81 (d, J=13.8 Hz, 0.8H), 7.27 (d, J=0.6 Hz, 0.2H), 7.23 (d, J=0.6 Hz, 0.8H), 5.40 (br s, 0.5H), 5.13 (br s, 0.5H), 4.36 (m, 1 H), 3.92-3.72 (m, 3H), 3.60-3.56 (m, 4H), 3.14 (m, 1 H), 2.69 (m, 3H), 2.20-2.06 (m, 1 H), 1.83-1.76 (m, 1 H), 1.46-

1.37 (m, 9H), 1.24-1.05 (m, 4H). General Procedure Step 6: To a solution of compound 7b (0.18 g, 0.3 mmol) (diastereoisomer A:B = 4:1 ) in EtOH (8 mL) was added triethylamine (0.21 mL, 1.45 mmol). The resulting solution was heated at reflux for 3 h, then cooled, diluted with CH₂CI₂ and washed with 1 N HCI and brine, before being dried over anhydrous Na₂S0₄ and concentrated in vacuo. Chromatography of the residue on Si0₂ eluting with 2% to 8% MeOH/CH₂CI₂ gave the free acid (0.15 g), which was dissolved in dioxane (10 mL). Dioxane saturated with HCI (g) (4 mL) was added to the above solution and the reaction mixture was heated at 60 °C for 1 h before being concentrated to dryness. The residue was then dissolved in MeOH (4 mL) and a small amount of Et₂O was added. This solution was stored at -20 °C overnight to induce crystallization. The resulting solid was collected by filtration and washed with Et₂0 to give compound 8b as the hydrochloride salt (diastereoisomer A: B = 4:1) (95 mg), m.p. 166-167 °C. ¹H NMR δ [(CD₃)₂SO] 15.1 (br s, 1 H), 9.65 (br s, 2H), 8.68 (s, 0.2H), 8.66 (s, 0.8H), 8.32 (d, J=0.8 Hz, 0.2H), 8.31 (d, J=0.8 Hz, 0.8H), 7.69 (d, J=13.8 Hz, 0.2H), 7.65 (d, J=13.8 Hz, 0.8H), 7.44 (d, J=0.8 Hz, 0.2H),

7.42 (d, J=0.8 Hz, 0.8H), 4.89 (br d, J=7.9 Hz, 1 H), 4.12 (m, 1 H), 3.80-3.65 (m, 2H), 3.58- 3.47 (obscured m (D₂0 exchange), 5H), 3.14 (m, 1 H), 2.56 (m, 3H), 2.35-2.28 (m, 1 H), 1.96-1.87 (m, 1 H), 1.18-0.89 (m, 4H). LCMS (APCI⁺) 457. Anal. Calcd for C₂₃H₂₅FN₄0₅.HCI + 1.25 H₂0 : C, 53.6; H, 5.6; N, 10.9. Found C, 53.5; H, 5.4; N, 10.8. To a solution of compound 7a (0.13 g, 0.21 mmol) (diastereoisomer B) in

EtOH/dioxane (1 :1 , 10 mL) was added triethylamine (0.15 mL, 1.05 mmol). The resulting solution was heated at reflux for 2 h, then cooled, diluted with CH₂CI₂ and washed with 1 N HCI and brine, before being dried over anhydrous Na₂S0₄ and concentrated in vacuo. The free acid was then dissolved in CH₂CI₂ (15 mL) to which methanolic HCI (1.25M, 4 mL) was added. After 3 h further saturated methanolic HCI (4 mL) was added and the reaction was stirred overnight (MS suggested the deprotection was only 30% complete and traces of methyl ester were present). Water (6 mL) was added and the solution was heated at reflux for 24 h. The solution was concentrated to dryness, re-dissolved in dioxane (15 mL) into which HCI (g) was then bubbled for 2 min. After 20 min at 80 °C (rxn complete by MS) the reaction was concentrated in vacuo and the residue crystallized from MeOH/Et₂0 to give compound 8a as the hydrochloride salt (70 mg), m.p. 252-255 °C. ¹H NMR δ [(CD₃)₂SO] 15.1 (br s, 1 H), 9.59 (br s, 2H), 8.67 (s, 1 H), 8.32 (d, J=0.7 Hz, 1 H), 7.69 (d, J=13.8 Hz, 1 H), 7.44 (d, J=0.7 Hz, 1 H), 4.87 (br d, J=7.9 Hz, 1 H), 4.14 (m, 1 H), 3.80 (m, 1 H), 3.71-3.64 (m, 2H), 3.54 (s, 3H), 3.43 (obscured m (D₂0 exchange), 1 H), 3.01 (m, 1 H), 2.54 (br s, 3H), 1.91 (m, 1 H), 1.71 -1.61 (m, 1 H), 1.20-0.92 (m, 4H). LCMS (APCI⁺) 457. Anal. Calcd for C₂₃H₂₅FN₄θ₅.HCI : C, 56.0; H, 5.3; N, 11.4; Cl, 7.2. Found C, 55.8; H, 5.4; N, 11.2; Cl, 7.1. All patents, and patent documents are incorporated by reference herein, as though individually incorporated by reference. The invention and the manner and process of making and using it, are now described in such full, clear, concise and exact terms as to enable any person skilled in the art to which it pertains, to make and use the same. It is to be understood that the foregoing describes preferred embodiments of the present invention and that modifications may be made therein without departing from the spirit or scope of the present invention as set forth in the claims. To particularly point out and distinctly claim the subject matter regarded as invention, the following claims conclude this specification.

Claims

What is claimed is:

A compound of formula I:

or a pharmaceutically acceptable salt thereof, wherein: X is N or C, provided that when X is N, R₅ is absent at that position; R_! is (CrC₆)alkyl, halo(C₁-C_β)alkyl, (C₃-C₆)cycloalkyl, halo(C₃-C₆)cycloalkyl aryl, and heteroaryl; R₂ is OH, 0(C C₆)alkyl, 0(C₃-C₆)cycloalkyl, O O— (CHR₂a)m^~° Q^R2b , wherein m is an integer of from 1 to 10, Q is O or is absent, and R_2a is H or (CrC₆)alkyl and R₂ is (Cp C₆)alkyl, aryl, or heteroaryl, ^0— (CHR_2a)_n— Y _^ vvhecejn >_2a j_{s as} defined above, n is an integer of from 2 to 10, Y is OH or NR_2oR_2d, wherein R_2c and R_2d are each independently H, (CrCeJalkyl, or (C₃-C₆)cycloalkyl, or NR_2d, wherein R_2d is as defined above,

wherein " ^WΛ " indicates the point of attachment, 2a is as defined above, R_2e is H or (Cι-C₆)alkyi, e is an integer of from 1 to 10, p is an integer of from 2 to 10, and X^ and Y_T are each independently NH or O; R₃, R₄, and R₅ are each independently H, halo, NH₂, (C-CβJalkyl, halo(C C₆)alkyl, (CrC₆)alkoxy, or halo(Cι-C₆)alkoxy; R_a and R_b are each independently H, (CrC₆) alkyl, haloalkyl, halo, or R_a and R_b taken together with the carbon to which they are attached form a 3,4,5 or 6-membered ring; and R_G and R_d are each independently H or (Cι-C₆)alkyl.

2. A compound of claiml which is set forth in Table 1 of the specification.

3. A compound of claim 1 which is set forth in Table 2 of the specification.

4. A compound of claim 1 which is set forth in Table 3 of the specification.

5. A compound of claim 1 which is set forth in Table 4 of the specification.

6. A compound of claim 1 which is set forth in Table 5 of the specification.

7. A compound having the structure of compound c, d, e, h, I, j, k or m set forth in Table 10 of the specification.

8. The compound of claim 1 , wherein RT is (CrC₆)alkyl, halo(C C₆)alkyl, (C₃-C₆)cycloalkyl, haIo(C₃-C₆)cycloalkyl aryl, and heteroaryl; R₂ is OH, O(Cι-Cβ)alkyl, 0(C₃-C₆)cycloaikyl, O 0-(CHR_2a)_m-0 QR_{2 j W}herein m is an integer of from 1 to 10, Q is O or is absent, and R_2a is H or (d-Q alkyl and R_2b is (d- C₆)alkyl, aryl, or heteroaryl, O— (CHR_2a)_n— Y _{^ W}h_erej_n R_2a js as defined above, n is an integer of from 2 to 10, Y is OH or NR_2cR_2d, wherein R_2c and R_2d are each independently H, (Cι-C₆)alkyl, or (C₃-C₆)cycloalkyl, or NR_2d, wherein R_2d is as defined above,

, wherein " ^ΛΛΛ " indicates the point of attachment, 2a is as defined above, R_2e is H or (Cι-C₆)alkyl, e is an integer of from 1 to 10, p is an integer of from 2 to 10, and -i and Y^ are each independently NH or O; R₃, R₄, and R₅ are each independently H, halo, NH₂, (d-CβJalkyl, halo(C C₆)alkyl, (CrC₆)alkoxy, or halo(d-C₆)alkoxy.

9. The compound of claim 1 , having a core structure set forth in Table 6 of the

specification, wherein A' is

10. The compound of claim 1 , having a core structure set forth in Table 7 of the

specification, wherein A' is

11. The compound of c

laim 1 , wherein is a structure set forth in

Table 8 of the specification.

12. A pharmaceutical formulation comprising a compound any one of claims 1-10 admixed with a pharmaceutically acceptable diluent, carrier, or excipient.

13. Use of a compound of any one of claims 1 -10 or a pharmaceutical formulation of claim 11 for the treatment of an antibacterial infection.