HETEROSUBSTITUTED PYRIDINE DERIVATIVES AS PDE 4 INHIBITORS

Abstract: The invention encompasses the novel compound of Formula (I) useful in the treatment of diseases, including asthma, by raising the level of cyclic adenosine-3',5'-monophosphate (cAMP) through the inhibition of phosphodiesterase IV (PDE 4). The invention also encompasses pharmaceutical compositions and methods for treatment.

Description: TITLE OF THE INVENTION HETEROSUBSTITUTED PYRIDINE DERIVATIVES AS PDE 4 INHIBITORS BACKGROUND OF THE INVENTION This invention relates to compounds and pharmaceutical compositions containing such compounds useful for treating diseases by raising the level of cyclic adenosine-3 ',5 -monophosphate (cAMP) through the inhibition of phosphodiesterase IV (PDE 4). Many hormones and neurotransmitters modulate tissue function by elevating intra-cellular levels of 3',5'-cyclic adenosine monophosphate (cAMP). The cellular levels of cAMP are regulated by mechanisms which control synthesis and breakdown. The synthesis of cAMP is controlled by adenyl cyclase which may be directly activated by agents such as forskolin or indirectly activated by the binding of specific agonists to cell surface receptors which are coupled to adenyl cyclase. The breakdown of cAMP is controlled by a family of phosphodiesterase (PDE) isoenzymes, which also control the breakdown of guanosine 3 ',5 '-cyclic monophosphate (cGMP). To date, nine members of the family have been described (PDE 1-9) the distribution of which varies from tissue to tissue. This suggests that specific inhibitors of PDE isoenzymes could achieve differential elevation of cAMP in different tissues, [for reviews of PDE distribution, structure, function and regulation, see Beavo & Reifsnyder (1990) TIPS, 1 1 : 150-155, Nicholson et al ( 1991) TIPS, 12: 19-27 and Houslay et al (1998) Adv. Pharmacol. 44: 225-342]. The availability of PDE isotype selective inhibitors has enabled the role of PDEs in a variety of cell types to be investigated. In particular it has been established that PDE 4 controls the breakdown of cAMP in many inflammatory cells, for example, basophils (Peachell P.T. et al., (1992) J. Immunol. 148 2503-2510) and eosinophils (Dent G. et al., (1991) Br. J. Pharmacol. 103 1339-1346) and that inhibition of this isotype is associated with the inhibition of cell activation. Furthermore, elevation of cAMP in airway smooth muscle has a spasmolytic effect. Consequently PDE 4 inhibitors are currently being developed as potential anti- inflammatory drugs particularly for the prophylaxis and treatment of asthma, by achieving both anti-inflammatory and bronchodilator effects. The application of molecular cloning to the study of PDEs has revealed that for each isotype there may be one or more isoforms. For PDE 4, it is has been shown that there are four isoforms (A, B, C and D) each coded for by a separate gene in both rodents (Swmnen JN. et al., (1989) Proc. Νatl. Acad Sci. USA 86 5325- 5329) and man (Bolger G. et al., (1993) Mol. Cell Biol. 13 6558-6571). The existence of multiple PDE 4s raises the prospect of obtaining inhibitors that are selective for individual isoforms, thus increasing the specificity of action of such inhibitors. This assumes that the different PDE 4 isoforms are functionally distinct. Indirect evidence in support of this comes from the selective distribution of these isoforms in different tissues (Swinnen et al., 1989, Bolger et al., 1993; Obernolte R. et al., (1993) Gene 129 239-247, ibid) and the high degree of sequence conservation amongst isoforms of different species. To date full length cDΝAs for human PDE 4A, B, C and D (Bolger et al., 1993 ibid; Obernolte et al., 1993 ibid; Mclaughlin M. et al , (1993) J. Biol. Chem. 268 6470-6476, Owens et al (1997) Cell. Signal., 9: 575-585) and rat PDE 4A, B and D (Davis R. et al , (1989) Proc. Νatl. Acad. Sci. USA 86 3604-3608; Swinnen JN. et al., (1991) J. Biol. Chem. 266 18370-18377), have been reported, enabling functional recombinant enzymes to be produced by expression of the cDΝAs in an appropπate host cell. These cDΝAs have been isolated by conventional hybridisation methods. The design of PDE 4 inhibitors for the treatment of inflammatory diseases such as asthma, has met with limited success to date Many of the PDE 4 inhibitors which have been synthesised have lacked potency and/or inhibit more than one type of PDE isoenzyme in a non-selective manner PDE 4 inhibitors that are relatively potent and selective for PDE 4, are reported to be emetic as well. Indeed this side effect has been so universal that experts have expressed their belief that the emesis expeπenced upon administration of a PDE 4 inhibitor, may be mechanism based One object of the present invention is to provide heterosubstituted pyπdines deπvatives that are inhibitors of PDE 4 at concentrations at which they have little or no inhibitory action on other PDE isoenzymes. These compounds inhibit the human recombinant PDE 4 enzyme and also elevate cAMP in isolated leukocytes. The compounds thus prevent, alleviate or reduce inflammation in the lungs, such as that induced by carrageenan, platelet-activating factor (PAF), ιnterleukm-5 (LL-5) or antigen challenge. The compounds also suppress the hyperresponsiveness of airway smooth muscle seen in inflammed lungs. Another object of the present invention is to provide compounds that have good oral activity and that at orally effective doses, exhibit a reduced incidence of the side-effects associated with known PDE 4 inhibitors, such as rolipram. The compounds of the invention are therefore of use in medicine, especially in the prophylaxis and treatment of asthma and other inflammatory conditions. SUMMARY OF THE INVENTION A compound represented by formula I: or a pharmaceutically acceptable salt or hydrate thereof wherein: Y represents N or N-oxide; R! and R^ are independently selected from: H, Cι_6alkyl and haloCi-6 alkyl, R3 and R4 are independently selected from H and Cj-6alkyl, or R^ and R^ attached to the same carbon atom taken together represent a carbonyl oxygen atom, or R3 and R^ attached to different carbon atoms considered in combination with the carbon atoms to which they are attached along with any intervening atoms and represent a saturated 5, 6 or 7 membered carbocychc ring, n represents an integer of from 0-6; Arl is selected from the group consisting of: (a) thienyl, (b) thiazolyl, (c) pyridyl, (d) phenyl and (e) naphthyl, said Arl bein: g optionally substituted with 1-3 members selected from the group consistin g of: (1) halo, (2) Ci- alkoxy, (3) Cι_7alkylthio, (4) CN, (5) C -6alkyl, (6) Ci-6hydroxyalkyl, (7) -CO2H, -CO2Ci-6alkyl, (8) NH(SO2Me), N(SO2Me)2, (9) SO2Me, (10) NO 2 , (11) Cι_6alkenyl, (12) halo Ci-6 alkyl, and (13) NH 2 , and when Ar^ represents a phenyl or naphthyl group with two or three substituents, two such substituents may be considered in combination and represent a 5 or 6 membered fused lactone ring. Pharmaceutical compositions and methods of treatment are also included. DETAILED DESCRIPTION OF THE INVENTION The present invention includes compounds represented by formula I: as well as pharmaceutically acceptable salts or hydrate thereof wherein: Y represents N or N-oxide; R! and R^ are independently selected from: H, Cι_6alkyl and haloCi-6 alkyl, R3 and R^ are independently selected from H and Ci-6alkyl, or R^ and R^ attached to the same carbon atom taken together represent a carbonyl oxygen atom, or R3 and R4 attached to different carbon atoms considered in combination with the carbon atoms to which they are attached along with any intervening atoms and represent a saturated 5, 6 or 7 membered carbocychc ring, n represents an integer of from 0-6; Ar* is selected from the group consisting of: (a) thienyl, (b) thiazolyl, (c) pyridyl, (d) phenyl and (e) naphthyl, said Ar* being optionally substituted with 1-3 members selected from the group consisting of: (1) halo, (2) Cι_6alkoxy, (3) Cι_7alkylthιo, (4) CN, (5) Cι_6alkyl, (6) Cι_6hydroxyalkyl, (7) -Cθ2H, -Cθ2Ci-6alkyl, (8) NH(SO2Me), N(SO2Me)2, (9) SO2Me, (10) NO 2 , (11) Ci-6alkenyl, (12) halo C]-6 alkyl, and (13) NH , and when Ar^ represents a phenyl or naphthyl group with two or three substituents, two such substituents may be considered in combination and represent a 5 or 6 membered fused lactone πng. The following definitions pertain to the terms used herein unless otherwise indicated. Halo is intended to include F, Cl, Br, and I HaloC]-6 alkyl refers to an alkyl group having 1-9 halo groups attached Examples include -CH2F, -CHF2 _ - CF3 , -CH2CH2F , -CHFCH2F , -CF2CH2F , -CF2CHF2 and -CF2CF3. Alkyl groups include straight or branched alkyl groups having 1-7 carbon atoms, and cyclic alkyl groups having from 3-7 carbon atoms. Cycloalkyl groups with alkyl substituent groups attached are also included. Examples of Cy 6 a lkyl groups include methyl, ethyl, propyl, 2-propyl, s- and t-butyl, butyl, pentyl, hexyl, 1,1-dιmethylethyl, cyclopropyl, cyclobutyl, cyclopentyl and cyclohexyl. Examples of Cι_6alkoxy groups include methoxy, ethoxy, propoxy, isopropoxy, cyclopropyloxy, cyclohexyloxy, and the like. Likewise, Ci-7alkylthιo is intended to include alkylthio groups of from 1 to 7 carbon atoms of a straight, branched or cyclic configuration. Examples of alkylthio groups include methylthio, propylthio, isopropylthio, cycloheptylthio, etc By way of illustration, the propylthio group signifies -SCH2CH 9 CH3. Preferred values of R ! and R2 are C[. alkyl and haloCi-6alkyl. More preferred values are selected from the group consisting of CH3, CH2F, CHF2, CF3 and most preferrably CHF2- Within this subset, all other variables are as originally defined. Preferred values of n are 0, 1, 2 and 3. More preferred values are 0, 1 and 2. Within these subsets, all other variables are as originally defined. Preferred values of Ar are phenyl and naphthyl. More preferred is phenyl. Within these subsets, all other variables are as originally defined. Preferred values of R3 and R are H and Cι_6alkyl. More preferred are H and methyl. Within these subsets, all other variables are as originally defined. Preferred values of R5 and R6 are H and Cj.βalkyl. More preferred is H. Within these subsets, all other variables are as originally defined. Preferably the Y is in the 2, 3 or 4 position relative to the point of attachment to the ethylene group. More preferably the Y is in the 4 position relative to the point of attachment to the ethylene group. Similarly, the pyridyl nitrogen atom shown is preferably in the 2, 3 or 4 position, relative to the attachment to the ethylene group. More preferably it is in the 3 position. A subset of compounds that is of particular interest relates to compounds of formula I wherein: R! and R2 are Ci-6alkyl and haloCi-6alkyl selected from the group consisting of CH3, CH2F, CHF2 and CF3 ; n is 0, 1, 2 or 3; Arl is phenyl or naphthyl; R3 and R are H and methyl and R5 and R6 are H or Ci-6alkyl. Within this subset, all other variables are as originally defined. More particularly, a subset of compounds that is of particular interest relates to compounds of formula I wherein: R ! and R2 are CHF2, and n is 0, 1 or 2. Within this subset, all other variables are as defined immediately above. Another subset of compounds that is of particular interest relates to compounds of formula I wherein: R 1 and R 2 are CHF2; n is 0, 1 or 2; R and R4 are H or methyl, R5 and R6 are H and Arl is phenyl. Withm this subset, all other variables are as defined immediately above. Examples of compounds falling with the present invention include the following: 1. 4-{2-[3,4-Bιs(dιfluoromethoxy)phenyl]-2-{6-[4- (tπfluoromethoxy)phenoxy]3-pyπdyl } ethyl }pyπdιne-N-oxιde, 2. 4-{ 2-[3,4-Bιs(dιfluoromethoxy)phenyl]-2-[6-(4- (methoxycarbonyl)phenoxy)3-pyπdyl]ethyl }pyndιne, 3. 4-{2-[3,4-Bιs(dιfluoromethoxy)phenyl]-2-[6-(4- (methoxycarbonyl)phenoxy)3-pyπdyl]ethyl }pyπdιne-N-oxιde, 4. 4-{2-[3,4-Bιs(dιfluoromethoxy)phenyl]-2-{6-[4-(2- hydroxypropan-2-yl)phenoxy]3-pyπdyl }ethyl }pyπdιne, 5 4-{2-[3,4-Bιs(dιfluoromethoxy)phenyl]-2-{6-[4-(2- hydroxypropan-2-yl)phenoxy]3-pyπdyl }ethyl }pyπdιne-N-oxιde, 6. 4-{ 2-[3,4-Bιs(dιfluoromethoxy)phenyl]-2-[6-(4- nιtrophenoxy)3-pyπdyl]ethyl }pyπdιne-N-oxιde, 7. 4-{2-[3,4-Bιs(dιfluoromethoxy)phenyl]-2-{6-[4- (methylsulfonylammo)phenoxy]3-pyπdyl }ethyl }pyπdιne-N-oxιde, 8. 4-{ 2-[3,4-Bιs(dιfluoromethoxy)phenyl]-2-{6-[4- (tπfluoromethyl)phenoxy]3-pyndyl } ethyl }pyπdme-N-oxιde, 9. 4-{ 2-[3,4-Bιs(dιfluoromethoxy)phenyl]-2-{6-[3- (methylsulfonylamιno)phenoxy]3-pyπdyl }ethyl }pyπdιne-N-oxιde, 10 4-{2-[3,4-Bιs(dιfluoromethoxy)phenyl]-2-{6-[4-(2- propenyl)phenoxy]3-pyπdyl } ethyl }pyπdιne-N-oxιde, 11 4-{2-[3,4-Bιs(dιfluoromethoxy)phenyl]-2-{6-[4-(2- propyl)phenoxy]3-pyπdyl }ethyl }pyπdιne-N-oxιde, 12. 4-{2-[3,4-Bιs(dιfluoromethoxy)phenyl]-2-{6-[4- (dιmethylsulfonylammo)phenoxy]3-pyπdyl } ethyl }pyπdme-N-oxιde, 13. 4-{2-[3,4-Bιs(dιfluoromethoxy)phenyl]-2-{6-[(4- hydroxymethyl-3-carboxyl)phenoxy]3-pyπdyl Jethyl }pyπdιne-N-oxιde sodium salt, 14. 4-{2-[3,4-Bιs(dιfluoromethoxy)phenyl]-2-[6-(benzyloxy)3- pyndyl ]ethyl }pyπdme-N-oxιde, 15 4-{ 2-[3,4-Bιs(dιfluoromethoxy)phenyl]-2-[6-(l- phenylethoxy)3-pyndyl]ethyl }pyπdme-N-oxιde, 16. 4-{2-[3,4-Bis(difluoromethoxy)phenyl]-2-[6-(3,4- difluorobenzyloxy)3-pyridyl]ethyl }pyridine-N-oxide, 17. 4-{2-[3,4-Bιs(difluoromethoxy)phenyl]-2-[6-(4- methylsulfonylbenzyloxy)3-pyridyl]ethyl }pyridine-N-oxide, 18. (Enantiomer-l)-4-{2-[3,4-Bis(difluoromethoxy)phenyl]-2-[6- (3,5-difluorobenzyloxy)3-pyridyl]ethyl}pyridine, 19. (Enantiomer-2)-4-{2-[3,4-Bis(difluoromethoxy)phenyl]-2-[6- (3,5-difluorobenzyloxy)3-pyridyl]ethyl}pyridine, 20. (Enantiomer-l)-4-{2-[3,4-Bis(difluoromethoxy)phenyl]-2-[6- (3,5-difluorobenzyloxy)3-pyridyl]ethyl }pyridine-N-oxide, 21. (Enantiomer-2)-4-{ 2-[3,4-Bis(difluoromethoxy)phenyl]-2-[6- (3,5-difluorobenzyloxy)3-pyridyl]ethyl}pyridine-N-oxide, 22. 4-{2-[3,4-Bis(difluoromethoxy)phenyl]-2-{6-[2-methyl-2-(4- fluorophenyl)propyloxy]3-pyridyl jethyl Jpyridine, 23. 4-{2-[3,4-Bis(difluoromethoxy)phenyl]-2-{6-[2-methyl-2-(4- fluorophenyl)propyloxy]3-pyridyl } ethyl }pyridine-N-oxide, 24. 4-{2-[3,4-Bis(difluoromethoxy)phenyl]-2-{6-[2-(4- fluorophenyl)ethoxy]3-pyridyl }ethyl Jpyridine, 25. 4-{ 2-[3,4-Bis(difluoromethoxy)phenyl]-2-{6-[2-(4- fluorophenyl)ethoxy]3-pyridyl }ethyl }pyridine-N-oxide, 26. 4-{ 2-[3,4-Bis(difluoromethoxy)phenyl]-2-[6-(4- trifluoromethylbenzyloxy)3-pyridyl]ethyl }pyridine-N-oxide, 27. 4-{2-[3,4-Bis(difluoromethoxy)phenyl]-2-[6-(4- trifluoromethoxybenzyloxy)3-pyridyl]ethyl }pyridine-N-oxide, 28. 4-{2-[3,4-Bis(difluoromethoxy)phenyl]-2-[6-(l,l-dimethyl-2- phenylethoxy)3-pyridyl]ethyl }pyridine-N-oxide, 29. 4-{2-[3,4-Bis(difluoromethoxy)phenyl]-2-[6-(2- thienylmethoxy)3-pyridyl]ethyl }pyridine-N-oxide, 30. 4-{2-[3,4-Bis(difluoromethoxy)phenyl]-2-{6-[l-methyl-l-(4- fluorophenyl)ethoxy]3-pyridyl }ethyl Jpyridine, 31. 4-{2-[3,4-Bis(difluoromethoxy)phenyl]-2-{6-[l-methyl-l-(4- fluorophenyl)ethoxy]3-pyridyl }ethyl }pyridine-N-oxide, 32. 4-{ 2-[3,4-Bis(difluoromethoxy)phenyl]-2-[6-(4- fluorobenzyloxy)3-pyridyl]ethyl}pyridine-N-oxide, 33. 4-{2-[3,4-Bιs(dιfluoromethoxy)phenyl]-2-[6-(4- chlorobenzyloxy)3-pyndyl]ethyl }pyπdιne-N-oxιde, 34. 4-{2-[3,4-Bιs(dιfluoromethoxy)phenyl]-2-{6-[l,2-dιhydro-l- ιsobenzofuranone-6-oxy]3-pyndyl }ethyl }pyπdιne-N-oxιde. As used herein, the terms "Enantιomer-1" and "Enamtιomer-2" refer respectively to the fast eluting isomer and the slow eluting isomer when puπfied by HPLC. The compounds descπbed herein contain one or more asymmetπc centers and may thus give rise to diastereomers and optical isomers The present invention is meant to include all such possible isomers and diastereomers as well as their racemic and resolved, enantiomeπcally pure forms and pharmaceutically acceptable salts thereof. The invention also encompasses a pharmaceutical composition that is compπsed of a compound of formula I in combination with a pharmaceutically acceptable earner. Preferably the composition is compπsed of a pharmaceutically acceptable earner and a non-toxic therapeutically effective amount of compound of formula I as described above. Moreover, withm this preferred embodiment, the invention encompasses a pharmaceutical composition for the treatment or prevention of disease by inhibition of PDE 4, resulting in an elevation of cAMP, compπsing a pharmaceutically acceptable earner and a non-toxic therapeutically effective amount of compound of formula I as described above. The term "pharmaceutically acceptable salts" refers to salts prepared from pharmaceutically acceptable non-toxic bases including inorganic bases and organic bases. Salts denved from inorganic bases include aluminum, ammonium, calcium, copper, feme, ferrous, lithium, magnesium, manganic salts, manganous, potassium, sodium, zinc, and the like. Particularly preferred are the ammonium, calcium, magnesium, potassium, and sodium salts. Salts denved from pharmaceutically acceptable organic non-toxic bases include salts of pnmary, secondary, and tertiary amines, substituted amines including naturally occurnng substituted amines, cyclic amines, and basic ion exchange resins, such as arginine, betame, caffeine, cholme, N,N-dιbenzylethylenedιamιne, diethylamme, 2- diethylaminoethanol, 2-dιmethylammoethanol, ethanolamine, ethylenediamme, N- ethylmorpho ne, N-ethylpipendme, glucamine, glucosamine, histidine, hydrabamine, isopropylamine, lysine, methylglucamine, morphohne, piperazine, pipendine, polyamine resms, proca e, punnes, theobromine, tπethylamine, tπmethylamme, tπpropylamine, trometham e, and the like. It will be understood that references to the compounds of Formula I are meant to also include the pharmaceutically acceptable salts. The compounds of formula I are selective and potent inhibitors of PDE 4. The biological activity and utility of the compounds may be demonstrated as described herein. The compounds according to the invention are thus of particular use in the prophylaxis and treatment of human diseases where an unwanted inflammatory response or muscular spasm (for example bladder or alimentary smooth muscle spasm) is present and where elevation of the cAMP levels may be expected to prevent or alleviate the disease or condition. Particular uses to which the compounds of the invention may be put include the prophylaxis and treatment of asthma, especially inflammed lung associated with asthma, cystic fibrosis, in the treatment of inflammatory airway disease, chronic bronchitis, eosinophi c granuloma, psoriasis and other benign and malignant pro ferative skin diseases, endotoxic shock, septic shock, ulcerative colitis, Crohn's disease, reperfusion injury of the myocardium and brain, inflammatory arthritis, chronic glomerulonephπtis, atopic dermatitis, urticana, adult respiratory distress syndrome, diabetes msipidus, allergic rhinitis, allergic conjunctivitis, vernal conjunctivitis, artenal restenosis and atherosclerosis. The compounds of the invention also suppress neurogenic inflammation. They are, therefore, analgesic, antitussive and antihyperalgesic in inflammatory diseases associated with irritation and pain. The compounds also elevate cAMP in lymphocytes and thereby suppress unwanted lymphocyte activation immune-based diseases such as rheumatoid arthntis, ankylosing spondylitis, transplant rejection and graft versus host disease The compounds also reduce gastnc acid secretion and therefore can be used to treat conditions associated with hypersecretion of gastnc acid. The compounds also suppress cytokine synthesis by inflammatory cells in response to immune or infectious stimulation They are, therefore, useful in the treatment of bactenal, fungal or viral induced sepsis and septic shock in which cytokines such as tumour necrosis factor (TNF) are key mediators The compounds of the invention also suppress inflammation and pyrexia due to cytokines and are, therefore, useful the treatment of inflammation and cytokine-mediated chronic tissue degeneration which occurs in diseases such as rheumatoid or osteo-arthntis. The over-production of cytokines such as TNF in bactenal, fungal or viral infections or in diseases such as cancer, leads to cachexia and muscle wasting. Compounds of the invention ameliorate these symptoms as well. The compounds of the invention elevate cAMP in certain areas of the brain and thereby counteract depression and memory impairment. Compounds of the invention suppress cell proliferation in certain tumour cells and can be used, therefore, to prevent tumour growth and invasion of normal tissues. For the prophylaxis or treatment of disease the compounds may be administered as pharmaceutical compositions, and according to a further aspect of the invention we provide a pharmaceutical composition which compnses a compound of formula (1) together with one or more pharmaceutically acceptable earners, excipients or diluents. For the treatment or prevention of any of the diseases or conditions descnbed herein, the compounds of formula I may be administered orally, topically, parenterally, by inhalation spray or rectally in formulations containing conventional non-toxic pharmaceutically acceptable carriers, adjuvants and vehicles The term parenteral as used herein includes subcutaneous, lntradermal, intravenous, intramuscular and intrasternal injection or infusion techniques In addition to the treatment of warm-blooded animals such as mice, rats, horses, cattle sheep, dogs, cats, etc., the compounds of the invention are useful for the treatment of humans. Oral pharmaceutical compositions containing the active ingredient are typically in the form of tablets, troches, lozenges, aqueous or oily suspensions, dispersible powders or granules, emulsions, hard or soft capsules, syrups or elixirs. Compositions intended for oral use may be prepared according to any method known to the art for the manufacture of pharmaceutical compositions and such compositions may contain one or more agents selected from the group consisting of sweetening agents, flavonng agents, colonng agents and preserving agents in order to provide pharmaceutically elegant and palatable preparations. Tablets contain the active ingredient in admixture with non-toxic pharmaceutically acceptable excipients which are suitable for the manufacture of tablets. These excipients may be for example, inert diluents, such as calcium carbonate, sodium carbonate, lactose, calcium phosphate or sodium phosphate; granulating and disintegrating agents, for example, corn starch, or alginic acid; binding agents, for example starch, gelatin or acacia, and lubncating agents, for example, magnesium stearate, steaπc acid or talc. The tablets may be uncoated or they may be coated by known techniques to delay disintegration and absorption in the gastrointestinal tract and thereby provide a sustained action over a longer penod. For example, a time delay matenal such as glyceryl monostearate or glyceryl distearate may be employed. They may also be coated by the technique described in the U.S. Patent 4,256,108, 4,166,452; and 4,265,874 to form osmotic therapeutic tablets for control release. In hard gelatin capsules, the active ingredient is typically mixed with an inert solid diluent, for example, calcium carbonate, calcium phosphate or kaolin. In soft gelatin capsules, the active ingredient is typically mixed with water or an oil medium, for example peanut oil, liquid paraffin or olive oil Aqueous suspensions contain the active matenal in admixture with excipients suitable for the manufacture of aqueous suspensions. Such excipients are suspending agents, for example sodium carboxymethyl-cellulose, methylcellulose, hydroxy-propylmethycellulose, sodium alginate, polyvinyl-pyrrohdone, gum tragacanth and gum acacia, dispersing or wetting agents may be a naturally-occurnng phosphatide, for example lecithin, or condensation products of an alkylene oxide with fatty acids, for example polyoxyethylene stearate, or condensation products of ethylene oxide with long chain aliphatic alcohols, for example heptadecaethylene- oxycetanol, or condensation products of ethylene oxide with partial esters denved from fatty acids and a hexitol such as polyoxyethylene sorbitol monooleate, or condensation products of ethylene oxide with partial esters denved from fatty acids and hexitol anhydndes, for example polyethylene sorbitan monooleate. The aqueous suspensions may also contain one or more preservatives, for example ethyl, or n- propyl, p-hydroxybenzoate, one or more colonng agents, one or more flavonng agents, and one or more sweetening agents, such as sucrose, sacchaπn or aspartame Oily suspensions may be formulated by suspending the active ingredient in a vegetable oil, for example arachis oil, olive oil, sesame oil or coconut oil, or in mineral oil such as liquid paraffin. The oily suspensions may contain a thickening agent, for example beeswax, hard paraffin or cetyl alcohol. Sweetening agents such as those set forth above, and flavonng agents may be added to provide a palatable oral preparation. These compositions may be preserved by the addition of an anti-oxidant such as ascorbic acid. Dispersible powders and granules suitable for preparation of an aqueous suspension by the addition of water provide the active ingredient in admixture with a dispersing or wetting agent, suspending agent and one or more preservatives. Suitable dispersing or wetting agents and suspending agents are exemplified by those already mentioned above. Additional excipients, for example sweetening, flavonng and colonng agents, may also be present The pharmaceutical compositions of the invention may also be in the form of an oil-in-water emulsion. The oil phase may be a vegetable oil, for example olive oil or arachis oil, or a mineral oil, for example liquid paraffin or mixtures of these. Suitable emulsifying agents may be naturally-occurring phosphatides, for example soy bean, lecithin, and esters or partial esters denved from fatty acids and hexitol anhydndes, for example sorbitan monooleate, and condensation products of the said partial esters with ethylene oxide, for example polyoxyethylene sorbitan monooleate. The emulsions may also contain sweetening and flavouring agents. Syrups and elixirs may be formulated with sweetening agents, for example glycerol, propylene glycol, sorbitol or sucrose Such formulations may also contain a demulcent, a preservative and flavonng and coloring agents. The pharmaceutical compositions may be in the form of a stenle injectable aqueous or oleagenous suspension This suspension may be formulated according to the known art using those suitable dispersing oi wetting agents and suspending agents which have been mentioned above. The stenle injectable preparation may also be a stenle injectable solution or suspension in a non-toxic parenterally-acceptable diluent or solvent, for example as a solution in 1,3-butane diol. Among the acceptable vehicles and solvents that may be employed are water, Ringer's solution and isotonic sodium chlonde solution. In addition, stenle, fixed oils may be employed as a solvent or suspending medium. For this purpose any bland fixed oil may be employed including synthetic mono- or diglyceπdes. In addition, fatty acids such as oleic acid find use in the preparation of injectables. Compounds of formula I may also be administered in the form of suppositones for rectal administration of the drug These compositions can be prepared by mixing the drug with a suitable non-irntating excipient which is solid at ordinary temperatures but liquid at normal body temperature and will therefore melt to release the drug. Examples of such matenals include cocoa butter and polyethylene glycols. For topical use, creams, ointments, jellies, solutions or suspensions, containing the compound of Formula I are employed. (For purposes of this application, topical application also includes mouth washes and gargles.) Dosage levels of the order of from about 0.01 mg to about 140 mg/kg of body weight per day are useful in the treatment of the above-indicated conditions, or alternatively about 0.5 mg to about 7 g per patient per day. For example, inflammation may be effectively treated by the administration of from about 0.01 to 50 mg of the compound per kilogram of body weight per day, or alternatively about 0 5 mg to about 3.5 g per patient per day. The amount of active ingredient that may be combined with the earner materials to produce a single dosage form will vary depending upon the host treated and the particular mode of administration. For example, a formulation intended for the oral administration to humans may contain from about 0 5 mg to about 5 g of active agent, compounded with an appropnate and convenient amount of earner matenal which may vary from about 5 to about 95 percent of the total composition Unit dosage forms will generally contain between from about 1 mg to about 500 mg of the active ingredient, typically 25 mg, 50 mg, 100 mg, 200 mg, 300 mg, 400 mg, 500 mg, 600 mg, 800 mg or 1000 mg It is understood, however, that the specific dose level for any particular patient will depend upon a vanety of factors including the age, body weight, general health, sex, diet, time of administration, route of administration, rate of excretion, drug combination and the seventy of the particular disease undergoing therapy. The compounds of the invention can be synthesized using the general synthesis schemes provided below It will be apparent to one skilled in the art that similar methodology could be used to prepare the enantiomers or the racemates of the illustrated compounds. The following abbreviations have the indicated meanings: SCHEME 1 The preparation of bromopynd e intermediate 1 is shown in Scheme 1 Monohthiation of 2,5-dιbromopyndιne followed by the addition 3,4- bιs(dιfluoromethoxy)benzaldehyde as found in U S Pat No 5,710,170 gave the secondary alcohol which was subsequently oxidized to the corresponding ketone with an oxidizing agent such as Mnθ2 SCHEME 1 SCHEME 2 The preparation of bromopyπdine intermediate 2 and 3 is shown in Scheme 2 The secondary alcohol II was converted to the corresponding chlonde III using a chlorinating agent such as thionyl chloride in the presence of a base This chlonde was condensed with the α-anion of ethyl 4-pyndyl acetate, affording the ester IV which upon hydrolysis with a base such as lithium hydroxide, followed by acidification with an acid such as hydrochlonc acid afforded the decarboxylated intermediate 2 Oxidation of the pyridme to the pyndine-N-oxide 3 was done with an oxidizing agent such as MMPP SCHEME 3 The general method for the preparation of substituted alcohols is presented in Scheme 3 Estenfication of a suitable carboxylic acid V under Fisher's conditions followed by dialkylation of the methyl ester VI with a base such as LHMDS and a suitable alkylatmg agent, afforded the coπesponding gem-α,α- disubstituted ester VII This intermediate is converted to the alcohol VJTI by reduction with a l educing agent such as lithium aluminum hydnde SCHEME 3 R a represents a substituent group attached to Arl, wherein Ar* represents phenyl. Up to 3 Ra groups may be present. The alkyl iodide provides the source for R3 and R4, which can be the same or different. SCHEME 4 6-Oxy-3-pyndyl denvatives of formula la and lb were prepared by the general method shown in Scheme 8. Bromopyrid e 1 was coupled with a suitable alcohol in the presence of a base such as potassium tert-butoxide. The reduction of the ketone XXI was performed with a reducing agent such as sodium borohydnde, followed by the conversion of the coπespondmg alcohol XXII to the chloride XXIII with a chlonnatmg agent such as thionyl chloride and a suitable base. This chlonde was condensed with the α-anion of ethyl 4-pyndyl acetate, affording the ester XXIV which upon hydrolysis with a base such as lithium hydroxide, followed by acidification afforded the decarboxylated intermediate la. Oxidation of the pyndme to the pyndme-N-oxide lb was done with an oxidizing agent such as MMPP. As noted above with respect to scheme 3, R a represents a substituent group attached to Ar and up to 3 R a groups may be present. SCHEME 4 XXIV la lb SCHEME 5 Alternatively, 6-Oxy-3-pyπdyl denvatives of formula la and lb were prepared by the general method shown in Scheme 9. 2,5-Dιbromopyndιne was coupled with a suitable alcohol in the presence of a base such as potassium hydroxide. Lithiation of the bromide XXV and condensation with 3,4-bιs(substιtuted) benzaldehyde afforded the secondary alcohol XXVI which was converted to the corresponding chlonde XXVII with a chlonnating agent such as thionyl chlonde and a suitable base. This chlonde was condensed with the α-anion of ethyl 4-pyndyl acetate, affording the ester XXVIII which upon hydrolysis with a base such as lithium hydroxide, followed by acidification with an acid such as HC1 afforded the decarboxylated intermediate Ic Oxidation of the pyndme to the pyndine-N-oxide Id was done with an oxidizing agent such as MMPP. SCHEME 5 XXV XXVIII lc Id SCHEME 6 Scheme 6 describes the preparation of several derivatives from the same carboxylic acid Treatment of this acid with a methylating agent such as diazomethane afforded the corresponding ester Ia2 which was derivatised to the pyridine-N-oxide Ibi in the presence of an oxidizing agent such as MMPP and to the tertiary alcohol Ia3 by the addition of an organocerium reagent, such as generated by the reaction of MeMgBr and CeCl3. This tertiary alcohol Ia3 could then by oxidized to the coπesponding pyridine-N-oxide Ib2 which upon treatment with an acid such as p-toluenesulfonic acid afforded insaturated derivative Ib3. MMPP I b lb, SCHEME 7 Mono and bιs(methylsulfonamιdes) were prepared by the general method presented in Scheme 7. The nitroaryl derivative Ia-j. was provided according to Scheme 4. The pyndine bis-sulfonamide Ia was obtained by reduction of the nitro group with a reducing agent such as Pd/C under an hydrogen atmosphere followed by sulfonylation of the corresponding amine Ia5 in the presence of a sulfonylating agent such as methylsulfonyl chlonde and a suitable base. This common intermediate could then be oxidized to the corresponding pyndme-N-oxide Ib4 with an oxidizing agent such as MMPP or hydrolyzed under basic conditions to the mono-sulfonamide Ia followed by the oxidation to the pyndine-N-oxide with an oxidizing agent such as MMPP. SCHEME 7 la, lb. SCHEME 8 Methylsulfone Ib6 was prepared by the method presented in Scheme 8. Thioether XXIIa was oxidized to the sulfone in the presence of an oxidizing agent such as MMPP followed by the conversion of the secondary alcohol to the corresponding chloride with a chlonnation agent such as thionyl chloride and a base such as Hunig's base. This chloride XXEIa was condensed with the α-anion of ethyl 4-pyridyl acetate, affording the ester XXIVa which upon hydrolysis with a base such as lithium hydroxide, followed by acidification with an acid such as hydrochloric acid afforded the decarboxylated intermediate. Oxidation of the pyridine to the pyridine- N-oxide Ib6 was done with an oxidizing agent such as MMPP. XXIIIa XXIVa Representative compounds of the invention are shown below. a Unless specified, all the compounds are racemic mixture. ^Sodium salt. C R, S mixture. ^Optically pure. TABLE 6 Ex 34 TABLE 7 7/V V/ RO POTENCY OF SOME REPRESENTATIVE PDE 4 INHIBITORS ASSAYS DEMONSTRATING BIOLOGICAL ACTIVITY LPS AND FMLP-INDUCED TNF-α AND LTB4 ASSAYS IN HUMAN WHOLE BLOOD Whole blood provides a protein and cell-nch milieu appropnate for the study of biochemical efficacy of anti -inflammatory compounds such as PDE 4- selective inhibitors Normal non-stimulated human blood does not contain detectable levels of TNF-α and LTB4 Upon stimulation with LPS, activated monocytes expresss and secrete TNF-a up to 8 hours and plasma levels remain stable for 24 hours Published studies have shown that inhibition of TNF-α by increasing intracellular cAMP via PDE 4 inhibition and/or enhanced adenylyl cyclase activity occurs at the transcriptional level. LTB4 synthesis is also sensitive to levels of intracellular cAMP and can be completely inhibited by PDE 4-selective inhibitors. As there is little LTB4 produced during a 24 hour LPS stimulation of whole blood, an additional LPS stimulation followed by fMLP challenge of human whole blood is necessary for LTB4 synthesis by activated neutrophils. Thus, using the same blood sample it is possible to evaluate the potency of a compound on two surrogate markers of PDE 4 activity in the whole blood. Fresh blood was collected in heparinized tubes by venipuncture from healthy human volunteers (male and female). These subjects had no apparent inflammatory conditions and had not taken any NSAIDs for at least 4 days prior to blood collection. Five hundred μL aliquots of blood were pre-incubated with either 2μL of vehicle (DMSO) or 2μL test compound at varying concentrations for 15 minutes at 37 C. This was followed by the addition of either lOμL vehicle (PBS) as blanks or lOμL LPS (lμg/ml final concentration, Sigma Chem, #L-2630 from E. coli, serotype 011 B4; diluted in 0.1% w/v BSA (in PBS)). After 24 hours of incubation at 37 C, another lOμL of PBS (blank) or lOμL of LPS (lμg/ml final concentration) was added to blood and incubated for 30 minutes at 37 C. The blood was then challenged with either lOμL of PBS (blank) or lOμL of fMLP (lμM final concentration, Sigma Chem #F-3506; diluted in 1% w/v BSA (in PBS)) for 15 minutes at 37 C. The blood samples were centrifuged at 1500xg for 10 minutes at 4 C to obtain plasma. A 50μL aliquot of plasma was mixed with 200μL methanol for protein precipitation and centrifuged as above. The supernatant was assayed for LTB4 using an enzyme immunoassay kit (Cayman Chemicals #520111) according to the manufacturer's procedure. TNF-α was assayed in diluted plasma (in PBS) using an ELISA kit (Cistron Biotechnology) according to manufacturer's procedure. ANTI- ALLERGIC ACTIVITY IN VIVO Compounds of the invention have been tested for effects on an IgE- mediated allergic pulmonary inflammation induced by inhalation of antigen by sensitised guinea pigs. Guinea pigs were initially sensitised to ovalbumin under mild cyclophosphamide-induced immunosuppression, by intraperitoneal injection of antigen in combinations with aluminium hydroxide and pertussis vaccine. Booster doses of antigen were given two and four weeks later and at six weeks, animals were challenged with aerosohsed ovalbumin whilst under cover of an intrapentoneally administered anti-histamine agent (mepyramine). After a further 48h, bronchial alveolar lavages (BAL) were performed and the numbers of eosmophils and other leukocytes in the BAL fluids were counted. The lungs were also removed for histological examination for inflammatory damage. Administration of compounds of the Examples (0.001-10mg/kg i.p. or p.o.), up to three times dunng the 48h following antigen challenge, lead to a significant reduction in the eosmophiha and the accumulation of other inflammatory leukocytes There was also less inflammatory damage in the lungs of animals treated with compounds of the Examples. SPA BASED PDE ACTIVITY ASSAY PROTOCOL Compounds which inhibit the hydrolysis of cAMP to AMP by the type- IV cAMP-specific phosphodiesterases were screened in 96-well plate format as follows: In a 96 well-plate at 30°C was added the test compound (dissolved in 2 μl DMSO), 188 ml of substrate buffer containing [2,8- H] adenosine 3',5'-cychc phosphate (cAMP, 100 nM to 50 μM), 10 mM MgCl2, 1 mM EDTA, 50 mM Tπs, pH 7.5. The reaction was initiated by the addition of 10 ml of human recombinant PDE- IV (the amount was controlled so that -10% product was formed in 10 min.). The reaction was stopped after 10 min by the addition of 1 mg of PDE-SPA beads (Ameisham). The product AMP generated was quantified on a Microbeta 96-well plate counter The signal in the absence of enzyme was defined as the background. 100% activity was defined as the signal detected in the presence of enzyme and DMSO with the background subtracted Percentage of inhibition was calculated accordingly. IC50 value was approximated with a non-lmear regression fit using the standard 4-parameter/multιple binding sites equation from a ten point titration. IC50 values shown in Table 7 were determined with 100 nM cAMP using the punfied GST fusion protein of the human recombinant phosphodiesterase IVa (met-248) produced from a baculovιrus/Sf-9 expression system. The invention will now be illustrated by the following non- mitmg examples in which, unless stated otherwise: (1) all operations were carried out at room or ambient temperature, that is, at a temperature in the range 18-25°C; evaporation of solvent was earned out using a rotary evaporator under reduced pressure (600-4000 pascals: 4.5-30 mm Hg) with a bath temperature of up to 60°C; the course of reactions was followed by thin layer chromatography (TLC) and reaction times are given for illustration only; melting points are uncoπected and 'd' indicates decomposition; the melting points given are those obtained for the matenals prepared as descnbed; polymorphism may result in isolation of matenals with different melting points in some preparations; the structure and punty of all final products were assured by at least one of the following techniques: TLC, mass spectrometry, nuclear magnetic resonance (NMR) spectrometry or microanalytical data; yields are given for illustration only; when given, NMR data is in the form of delta (δ) values for major diagnostic protons, given in parts per million (ppm) relative to tetramethylsilane (TMS) as internal standard, determined at 300 MHz, 400 MHz or 500 MHz using the indicated solvent; conventional abbreviations used for signal shape are s. singlet, d doublet; t tπplet; m. multiplet; br broad; etc.: in addition "Ar" signifies an aromatic signal; chemical symbols have their usual meanings; the following abbreviations have also been used v (volume), w (weight), b.p. (boiling point), m.p (melting point), L (lιter(s)), mL (milliliters), g (gram(s)), mg (mιlhgrams(s)), mol (moles), mmol (milhmoles), eq (equιvalent(s)) EXAMPLE 1 4-{ 2-[3,4-BIS(DIFLUOROMETHOXY)PHENYL]-2-{ 6-[4- (TRIFLUOROMETHOXY)PHENOXY] -3-PYRIDYL } ETHYL } PYRIDINE-N- OXIDE Step 1 [3,4-Bis(difluoromethoxy)phenyll-{ 6-[4-(trifluoromethoxy)phenoxyl-3- pyπdvUmethanone To a 0°C solution of 4-tπfluoromethoxyphenol (0.33 mL, 2 54 mmol) in 5 mL of anhydrous DMF, was added dropwise 2.54 mL (2.54 mmol) of a 1.0 M solution of potassium t-butoxide in THF followed by 500 mg (1.27 mmol) of intermediate 1. The resulting orange solution was stirred 20 h at room temperature, quenched by the addition of a saturated aqueous NH4C1 solution and diluted with Et2O The organic layer was washed with a 0.5 N NaOH solution, water and bπne, dned over MgSO4 and concentrated under reduced pressure The residue was puπfied by flash chromatography on silica gel (10% Ethyl acetate/toluene) to afford the desired aryl ether as an oil (484 mg, 77 %). Step 2 [3,4-Bιs(dιfluoromethoxy)phenyl1-{6-[4-(tnfluoromethoxy)phenoxy1-3- pyndyl ) methanol To a 0°C solution of ketone (484 mg, 0 985 mmol) from Step 1 above 12 mL of a 5 : 1 mixture of THF : MeOH, was added slowly 75 mg (1.97 mmol) of NaBH4. The resulting solution was stirred 2 5 h at 0 °C, quenched with a saturated aqueous NH4C1 solution and diluted with ethyl acetate. The organic layer was washed with brine, dried over MgSO4 and concentrated under reduced pressure The residue was used directly for the next step without any punfication. Step 3 [3,4-Bιs(dιfluoromethoxy)phenyn-{6-|4-(trιfluoromethoxy)phenoxyl-3- pyndyl jchloromethane To a 0°C solution of alcohol (500 mg, 1 01 mmol) from Step 2 above and ι-Pr2NEt (400 mL, 2.22 mmol) in 14 mL of a 1 : 1 mixture of toluene:THF, was slowly added SOC12 (100 mL, 1 11 mmol). The resulting yellow solution was stirred 30 minutes at 0°C, quenched with water and diluted with ethyl acetate The organic layer was washed with brine, dried over MgSO4 and concentrated under reduced pressure. The residue was used directly for the next step without any punfication Step 4 4-{ l-Carbethoxy-2-r3,4-bιs(dιfluoromethoxy)phenyll-2-{6-[4- (tnfluoromethoxy)phenoxy1-3-pyndyl ) ethyl ) pyndine To a solution of ethyl 4-pyndyl acetate (502 mg, 3.03 mmol) and HMPA (530 mL, 3.03 mmol) in 12 mL of THF, was slowly added 6.1 mL (3.03 mmol) of a 0.5 M solution of KHMDS in toluene. The resulting cloudy orange solution was stiπed 10 minutes at room temperature followed by the addition of a THF (6 mL) solution of the crude chlonde from Step 3 above. The resulting mixture was stirred 30 minutes at room temperature, quenched with a saturated aqueous NH4CI solution and diluted with ethyl acetate The organic layer was washed with water and bnne, dπed over MgSO4 and concentrated under reduced pressure The residue was used directly for the next step without any punfication Step 5 4-{ 2-[3,4-Bis(difluoromethoxy)phenyll-2-{6-[4-(tnfluoromethoxy)phenoxyl-3- pyndyl ) ethyl } pyndine To a solution of the crude ester from Step 4 above in 25 mL of a 3: 1 : 1 mixture of THF:MeOH:water, was added 5.1 mL (10.3 mmol) of a 2 N solution of LiOH. The resulting solution was stirred at 65 °C for 1.5 h, cooled down to room temperature followed by the addition of 10 mL of a 1.0 N HCl solution. The resulting mixture was rotovaped down to evaporate MeOH and the aqueous residue was diluted with ethyl acetate. The organic layer was washed with water and bnne, dned over MgSO4 and concentrated under reduced pressure The residue was punfied by flash chromatography on silica gel (50% Ethyl acetate/hexane) to afford the desired pyndine as an oil (380 mg, 68 % from Step 2). Step 6 4-{ 2-[3,4-Bιs(dιfluoromethoxy)phenyn-2-{6-[4-(tnfluoromethoxy)phenoxyl-3- pyπdyl } ethyl )pyndme-N-oxιde To a solution of 4-{2-[3,4-bιs(dιfluoromethoxy)phenyl]-2-{6-[4- (tπfluoromethoxy)phenoxy]-3-pyndyl }ethyl }pyπdιne (340 mg, 0.598 mmol) from Step 5 above in a mixture of 6 mL of CH2CI2 and 0 6 mL of MeOH, was added MMPP (222 mg, 0 359 mmol) in one portion The mixture was stirred 24 h at room temperature and the reaction was completed with an other 50 mg of MMPP. The reaction was quenched with a saturated aqueous NaHCO3 solution and diluted with CH2CI2. The organic layer was washed with brine, dried over MgSO4 and concentrated under reduced pressure. The residue was punfied by flash chromatography on silica gel (5% MeOH/CH2C12) to afford the title compound as an amorphous solid (340 mg, 97 %). iH NMR (500 MHz, Acetone-d6) δ 8.10 (d, IH), 7.94 (m, 2H), 7.89 (m, IH), 7.41 (s, IH), 7.36-7.33 (d, 2H), 7.28 (d, IH), 7.23-7 18 (m, 4H), 6.98 (d, IH), 6.95 (t, IH), 6.93 (t, IH), 4.56 (t, IH), 3.49 (m, 2H). EXAMPLE 2 4-{ 2-[3,4-BIS(DIFLUOROMETHOXY)PHENYL]-2-{ 6-[4- (METHOXYCARBONYL)PHENOXY]-3-PYRΓDYL}ETHYL}PYRΓDΓNE Step 1 [3,4-Bιs(dιfluoromethoxy)phenyll-{ 6-[4-(methoxycarbonyl)phenoxyl-3- pyπdyl Imethanone To a 0°C solution of intermediate 1 (507 mg, 1.29 mmol) and 4- methoxycarbonylphenol (391 mg, 2.6 mmol) in 5 mL of anhydrous DMF, was added dropwise 2.6 mL (2.6 mmol) of a 1.0 M solution of potassium t-butoxide. The resulting orange solution was stirred 15 h at room temperature, quenched by the addition of a saturated aqueous NH4CI solution and diluted with Et2θ. The organic layer was washed with 0.1 N NaOH solution, water and bnne, dried over MgSO4 and concentrated under reduced pressure. The residue was used directly for the next step without any punfication. Step 2 r3,4-Bιs(dιfluoromethoxy)phenyll-{6-[4-(methoxycarbonyl)phenoxyl-3- pyndyl } methanol To a 0 ° C solution of ketone (540 mg, 1.16 mmol) from Step 1 in 12 mL of a 5 . 1 mixture of THF : MeOH, was added slowly 88 mg (2.3 mmol) of NaBH4. The resulting solution was stirred 30 minutes at 0 °C, quenched with a saturated aqueous NH4CI solution and diluted with ethyl acetate The organic layer was washed with brine, dried over MgSO4 and concentrated under reduced pressure The residue was used directly for the next step without any punfication Step 3 [3,4-Bιs(dιfluoromethoxy)phenyll-{ 6-[4-(methoxycarbonyl)phenoxyl-3- pyndyl lchloromethane To a 0 °C solution of alcohol (535 mg, 1.14 mmol) from step 2 and z-Pr2NEt (436 mL, 2.5 mmol) in 10 mL of anhydrous toluene, was slowly added SOCI2 (145 mL, 2.0 mmol) The resulting yellow solution was stiπed 30 minutes at 0 °C, 10 minutes at room temperature, quenched with water and diluted with ethyl acetate. The organic layer was washed with bnne, dried over MgSO4 and concentrated under reduced pressure The residue was used directly for the next step without any punfication. Step 4 4-{ l-Carbethoxy-2-r3,4-bιs(dιfluoromethoxy)phenyn-2-{6-r4- (methoxycarbonyl)phenoxyl-3-pyndyl lethyl Ipyndme To a solution of ethyl 4-pyndyl acetate (564 mg, 3.42 mmol) and HMPA (594 mL, 3.42 mmol) in THF, was slowly added 6 8 mL (3.42 mmol) of a 0.5 M solution of KHMDS in toluene. The resulting cloudy orange solution was stiπed 10 minutes at room temperature followed by the addition of a THF (8 mL) solution of the crude chloride from Step 3. The resulting mixture was stiπed 30 minutes at room temperature, quenched with a saturated aqueous NH4CI solution and diluted with ethyl acetate The organic layer was washed with water and bnne, dned over MgSO4 and concentrated under reduced pressure The residue was used directly for the next step without any purification Step 5 4-{ 2-[3,4-Bιs(dιfluoromethoxy)phenyll-2-{ 6-r4-(methoxycarbonyl)phenoxy1-3- pyndyUethyl Ipyπdine To a solution of the crude ester from Step 4 above in 25 mL of a 3 : 1 : 1 mixture of THF : MeOH : water, was added 5 1 mL (10.3 mmol) of a 2 N solution of LiOH The resulting solution was stiπed at 65 °C for 1.5 h, cooled down to room temperature followed by the addition of 11 mL of a 1 0 N HCl solution The resulting mixture was rotovaped down to evaporate MeOH and the aqueous residue was diluted with ethyl acetate The organic layer was washed with water and bnne, dned over MgSO4 and concentrated under reduced pressure The residue was dissolved in ethyl acetate and treated with CH2N2 and monitored by TLC until all the carboxylic acid have been estenfied. The solution was concentrated under reduced pressure and the residue was punfied by flash chromatography on silica gel (70% Ethyl acetate/hexane) to afford the title compound as a viscous oil (432 mg, 62 % from Step 1). !H NMR (300 MHz, Acetone-d6) δ 8 38 (d, 2H), 8.14 (d, IH), 8.05-7 99 (m, 2H), 7 93 (dd, IH), 7.43 (d, IH), 7.36 (dd, IH), 7.28 (d, IH), 7.22-7.14 (m, 4H), 7.01 (d, IH), 6 96 (t, IH), 6.94 (t, IH), 4 63 (t, IH), 3.87 (s, 3H), 3 50 (d, 2H) EXAMPLE 3 4-{2-[3,4-BIS(DIFLUOROMETHOXY)PHENYL]-2-{6-[4- (METHOXYCARBONYL)PHENOXY]-3-PYRIDYL }ETHYL } PYRIDPNE-N- OXIDE To a solution of 4-{2-[3,4-bιs(dιfluoromethoxy)phenyl]-2-{6-[4- (methoxycarbonyl)phenoxy]-3-pyndyl}ethyl }pyπdme from Example 1 (249 mg, 0.46 mmol) in a mixture of 5 mL of CH2CI2 and 0.5 mL of MeOH, was added MMPP (171 mg, 0.28 mmol) in one portion. The mixture was stirred 24 h at room temperature, quenched with a saturated aqueous NaHCO3 solution and diluted with CH2CI2. The organic layer was washed with bnne, dned over MgSO4 and concentrated under reduced pressure. The residue was purified by flash chromatography on silica gel (Gradient 20% to 40%) EtOH/ethyl acetate) to afford the title compound as a viscous oil (260 mg, 71 %). l U NMR (400 MHz, Acetone-d6) δ 8.15 (d, IH), 8.05-8 01 (m, 2H), 7.98-7.92 (m, 3H), 7.44 (d, IH), 7.36 (dd, IH), 7.29 (d, IH), 7.23-7.16 (m, 4H), 7.03 (d, IH), 6.97 (t, IH), 6.94 (t, IH), 4.60 (t, IH), 3.89 (s, 3H), 3.50 (dd, 2H). EXAMPLE 4 4-{ 2-[3,4-BIS(DIFLUOROMETHOXY)PHENYL]-2-{6-[4-(2-HYDROXYPROPAN- 2-YL)PHENOXY]-3-PYRIDYL } ETHYL } PYRIDINE A suspension of dry CeCl3 (2.7 g, 11.0 mmol) in 50 mL of THF was refluxed 1 h , cooled to 0 °C and treated with 3.7 mL (1 1 0 mmol) of a 3.0 M solution of MeMgBr in Et2θ. The resulting mixture was stiπed 1 h at 0 ° C, cooled to -40 °C followed by the addition of a THF (10 mL) solution of 4-{ 2-[3,4- bιs(dιfluoromethoxy)phenyl]-2-{6-[4-(methoxycarbonyl)phenoxy]-3- pyndyl }ethyl } pyndine. After stirnng 30 minutes at -40 °C, the reaction was quenched with a saturated aqueous NH4CI solution and diluted with ethyl acetate. The organic layer was washed with water and bnne, dned over MgSO4 and concentrated under reduced pressure. The residue was punfied by flash chromatography on silica gel (Gradient 5% to 10% EtOH/ethyl acetate) to afford the title compound as a foam (1.1 g, 99 %). l H NMR (300 MHz, Acetone-d6) δ 8.38 (s, 2H), 8.07 (d, IH), 7 84 (dd, IH), 7.55-7 49 (m, 2H), 7.40 (s, IH), 7.34 (dd, IH), 7.26 (d, IH), 7.22-7.16 (m, 2H), 7.03- 6.96 (m, 2H), 6.94 (t, IH), 6.93 (t, IH), 6.88 (d, 1H),4.59 (t, IH), 4.00 (s, IH), 3.50 (d, 2H), 1.50 (s, 6H). EXAMPLE 5 4-{2-[3,4-BIS(DIFLUOROMETHOXY)PHENYL]-2-{6-[4-(2-HYDROXYPROPAN- 2- YL)PHENOXY]-3-PYRIDYL } ETHYL } PYRIDINE-N-OXIDE Following the procedure described in Example 3 but using 4-{2-[3,4- bis(difluoromethoxy)phenyl]-2-{6-[4-(2-hydroxypropan-2-yl)phenoxy]-3- pyridyl }ethyl}pyridine as starting material, the title compound was obtained as a white foam (23 mg, 77%). l R NMR (400 MHz, Acetone-d6) δ 8.08 (d, IH), 7.98-7.94 (m, 2H), 7.85 (dd, IH), 7.55-7.50 (m, 2H), 7.42 (s, IH), 7.35 (dd, IH), 7.27 (d, IH), 7.21 (d, 2H), 7.03- 6.97 (m, 2H), 6.96 (t, IH), 6.94 (t, IH), 6.90 (d, IH), 4.55 (t, IH), 3.50 (d, 2H), 1.51 (s, 6H). EXAMPLE 6 4- { 2-[3,4-BIS(DIFLUOROMETHOXY)PHENYL]-2-[6-(4-NITROPHENOXY)-3- PYRΓDYL]ETHYL}PYRIDΓNE-N-OXIDE Step 1 [3.4-Bis(difluoromethoxy)phenv]l-[6-(4-nitrophenoxy)-3-pyridyl1methanone Following the procedure described in Example 1 , Step 1 but substituting 4-nitrophenol for 4-trifluoromethoxyphenol, the desired aryl ether was obtained as an oil (1.02 mg, 89 %). Step 2 [3,4-Bis(difluoromethoxy)phenyll-[6-(4-nitrophenoxy)-3-pyridyl1methanol The procedure for the reduction of the ketone described in Example 1, Step 2 was applied using the product of step 1 above as starting material. The alcohol obtained was used directly for the next step without any purification. Step 3 3,4-Bis(difluoromethoxy)phenyll-r6-(4-nitrophenoxy)-3-pyridyllchloromethane The procedure for the formation of the chloride described in Example 1, Step 3 was applied using the product of Step 2 above as starting material. The chloride obtained was used directly for the next step without any purification. Step 4 4-\ l-Carbethoxy-2-[3,4-bis(difluoromethoxy)phenyn-2-r6-(4-nitrophenoxy)-3- pyridyllethyl Ipyridine The procedure for the alkylation with ethyl 4-pyridylacetate described in Example 1, Step 4 was applied using the product of Step 3 above as starting material. The ethyl ester obtained was used directly for the next step without any purification. Step 5 4-{ 2-f3,4-bis(difluoromethoxy)phenvπ-2-r6-(4-nitrophenoxy)-3- pyridyl] ethyl Ipyridine The procedure for the hydrolysis/decarboxylation described in Example 1, Step 5 was applied using the product of Step 4 above as starting material. The protected aminopyridine was obtained as an oil (710 mg, 60% for 4 steps). Step 6 4-{ 2-F3,4-Bis(dif]uoromethoxy)phenyl1-2-|6-(4-nitrophenoxy)-3- pyridyllethyl ) pyridine-N-oxide The procedure for the oxidation of the pyridine group described in Example 1, Step 6 was applied using the product of Step 5 above as starting material. The title compound was obtained as an oil (103 mg, 91%). l R NMR (500 MHz, Acetone-dό) δ 8.27 (d, 2H), 8.19 (s, IH), 7.99- 7.94 (m, 3H), 7.44 (s, IH), 7.38-7.19 (m, 4H), 7.10 (d, 2H), 6.96 (t, IH), 6.94 (t, IH), 4.60 (t, IH), 3.51 (m, 2H). EXAMPLE 7 4-{ 2-[3,4-BIS(DIFLUOROMETHOXY)PHENYL]-2-{ 6-[4- (METHYLSULFONYLAMINO)PHENOXY]-3-PYRIDYL}ETHYL}PYRIDINE-N- OXJDE Step 1 4-< 2- 3,4-bιs(dιfluoromethoxy)phenyll-2-r6-(4-amιnophenoxy)-3- pyπdyllethyl ) pyndine To a solution of 4-{2-[3,4-bιs(dιfluoromethoxy)phenyl]-2-[6-(4- nιtrophenoxy)-3-pyπdyl]ethyl }pyndιne (600 mg, 1.13 mmol) from Example 6, Step 5 in 20 L EtOH, was added 120 mg of Pd/C 10% and the resulting mixture was stirred 20 h under H2 atmosphere. The reaction was filtered on cehte, washed with ethyl acetate and concentrated under reduced pressure. The residue was punfied by flash chromatography on silica gel (10% EtOH/Ethyl acetate) to afford the amine as an oil (500 mg, 88%). Step 2 4-{ 2-[3,4-Bιs(dιfluoromethoxy)phenyn-2-{6-[4-(methylsulfonylamιno)phenoxyl-3- pyndyl > ethyl Ipyridine To a 0 °C solution of amine from Step 1 above (200 mg, 0.4 mmol) in 6 mL of CH2CI2 was added 0.28 mL (2.0 mmol) of Et3N followed by 0 1 1 mL (1.4 mmol) of methylsulfonyl chlonde. The solution was stiπed at 0 °C for 1.5 h. quenched with water and diluted with CH2CI2 The organic layer was washed with brine, dned over MgSO4 and concentrated under reduced pressure. The residue was dissolved in 10 mL of a 1 : 1 :1 mixture of THF.MeOH. l N K2CO3, stiπed for 3.5 h at room temperature, quenched with a saturated aqueous NH4CI solution and diluted with ethyl acetate. The organic layer was washed with bnne, dned over MgSO4 and concentrated under reduced pressure. The residue was punfied by flash chromatography on silica gel (100% ethyl acetate) to afford the methyl sulfonamide as a foam (1 14 mg, 51 %). Step 3 4-{ 2-[3,4-Bιs(dιfluoromethoxy)phenyll-2-<6-[4-(methylsulfonylamιno)phenoxyl-3- pyπdyl lethyl }pyπdιne-N-oxιde The procedure for the oxidation of the pyndine group descnbed in Example 1, Step 6 was applied using the product of Step 2 above as starting matenal. The title compound was obtained as a foam (85 mg, 73%). iH NMR (500 MHz, Acetone-d6) δ 8.71 (brs, IH), 8.08 (d, IH), 7.97 (d, 2H), 7 85 (dd, IH), 7.41 (d, IH), 7 37-7.33 (m, 3H), 7.28 (d, IH), 7.20 (d, 2H). 7.10-6.78 (m, 5H), 4.54 (t, IH), 3.49 (m, 2H), 2.97 (s, 3H). EXAMPLE 8 4-{2-[3,4-BIS(DIFLUOROMETHOXY)PHENYL]-2-{6-[4- (TRΓFLUOROMETHYL)PHENOXY]-3-PYRID YL } ETHYL } PYRΓDINE-N-OXΓDE Following the procedure descnbed in Example 1 but substituting 4- tπfluoromethylphenol for 4-tπfluoromethoxyphenol, the title compound was obtained as a white foam (270 mg). l H NMR (500 MHz, Acetone-d6) d 8 14 (d, IH), 7 98-7.92 (m, 3H), 7 73 (d, 2H), 7.43 (d, IH), 7.35 (dd, IH), 7.29 (m, 3H), 7 19 (d, 2H), 7 03 (d, IH), 6.96 (t, IH), 6.94 (t, IH), 4.58 (t, IH), 3.50 (m, 2H). EXAMPLE 9 4-{2-[3,4-BIS(DIFLUOROMETHOXY)PHENYL]-2-{6-[3- (METHYLSULFONYLAMINO)PHENOXY]-3-PYRIDYL}ETHYL}PYRIDINE-N- OXIDE Following the procedure described in Example 1, Step 1 but substituting 3-nιtrophenol for 4-tπfluoromethoxyphenol, the desired aryl ether was obtained as an oil (1 06 g, 92%). Step 2 [3,4-Bιs(dιfluoromethoxy)phenylH6-(3-mtrophenoxy)-3-pyndyllmethanol The procedure for the reduction of the ketone descnbed in Example 1. Step 2 was applied using the product of Step 1 above as starting matenal The alcohol obtained was used directly for the next step without any purification. Step 3 [3,4-Bιs(dιfluoromethoxy)phenyl1-r6-(3-nιtrophenoxy)-3-pyndyllchloromethane The procedure for the formation of the chlonde descnbed m Example 1, Step 3 was applied using the product of Step 2 above as starting material. The chlonde obtained was used directly for the next step without any punfication. Step 4 4-{ l-Carbethoxy-2-r3,4-bιs(dιfluoromethoxy)phenyn-2-r6-(3-nιtrophenoxy)-3- pyndyllethyl Ipyπdine The procedure for the alkylation with ethyl 4-pyπdyl acetate descnbed in Example 1, Step 4 was applied using the product of Step 3 above as starting material. The ethyl ester obtained was used directly for the next step without any punfication. Step 5 4-{2-f3,4-bιs(dιfluoromethoxy)phenyl1-2-[6-(4-nιtrophenoxy)-3- pyndyllethyl Ipyridine The procedure for the hydrolysis/decarboxylation descnbed m Example 1, Step 5 was applied using the product of Step 4 above as starting matenal. The protected aminopyndme was obtained as an oil (410 mg, 34% for 4 steps). Step 6 4-{ 2- 3,4-bιs(dιfluoromethoxy)phenyll-2-[6-(4-amιnophenoxy)-3- pyndyllethyl Ipyndine The procedure for the reduction of the nitro group descnbed in Example 7, Step 1 was applied using the product of Step 5 above as starting matenal. The amine was obtained as an oil (185 mg, 48%). Step 7 4-{ 2-f3,4-Bιs(dιfluoromethoxy)phenyll-2-{6-r3-(methylsulfonylamιno)phenoxy1-3- pyπdyl 1 ethyl } pyndme The procedure for the sulfonylation of the amine group descnbed in Example 7, Step 2 was applied using the product of Step 6 above as starting matenal. The sulfonamide was obtained as an oil (80 mg, 37%). Step 8 4-{ 2-r3,4-Bis(difluoromethoxy)phenyll-2-{6-[3-(methylsulfonylamino)phenoxy1-3- pyridyl } ethyl I pyridine-N-oxide The procedure for the oxidation of the pyridine group described in Example 1, Step 6 was applied using the product of Step 7 above as starting material. The title compound was obtained as a foam (55 mg, 67%). *H NMR (500 MHz, Acetone-dό) δ 9.04 (brs, IH), 8.21 (d, IH), 8.10 (d, 2H), 7.98 (dd, IH), 7.54 (s, IH), 7.46 (m, 3H), 7.40 (d, IH), 7.31 (d, 2H), 7.25 (dd, IH), 7.22-6.90 (m, 5H), 4.67 (t, IH), 3.61 (m, 2H), 3.12 (s, 3H). EXAMPLE 10 4-{ 2-[3,4-BIS(DIFLUOROMETHOXY)PHENYL]-2-{6-[4-(2- PROPENYL)PHENOXY]-3-PYRIDYL } ETHYL } PYRΓDΓNE-N-OXIDE To a solution of 148 mg (0.26 mmol) of 4-{2-[3,4- bis(difluoromethoxy)phenyl]-2-{6-[4-(2-hydroxypropan-2-yl)phenoxy]-3- pyridyl Jethyl } pyridine-N-oxide (Example 5) in 3.0 mL of CH2CI2 was added 85 mg (0.45 mmol) of p-toluenesulfonic acid at room temperature. The solution was stirred 2 days at room temperature, quenched with a saturated aqueous NaHCO3 solution and diluted with CH2CI2. The organic layer was washed with brine, dried over MgSO4 and concentrated under reduced pressure. The residue was purified by flash chromatography on silica gel (Gradient 20% to 30% EtOH/ethyl acetate) to afford the title compound as a foam (98 mg, 68 %). H NMR (500 MHz, Acetone-d6) δ 8.09 (d, IH), 7.95 (d, 2H), 7.86 (dd, IH), 7.54-7.50 (m, 2H), 7.41 (s, IH), 7.34 (dd, IH), 7.27 (d, IH), 7.18 (d, 2H), 7.06-7.03 (m, 2H), 6.95 (t, IH), 6.93 (t, IH), 6.93 (d, IH), 5.38 (s, IH), 5.07 (s, IH), 4.55 (t, IH), 3.5 (dd, 2H), 2.12 (s, 3H). EXAMPLE 11 4- { 2-[3,4-BIS(DIFLUOROMETHOXY)PHENYL]-2-{ 6-[4-(2- PROPYL)PHENOXY]-3-PYRΓDYL}ETHYL}PYRIDΓNE-N-OXΓDE Following the procedure described in Example 1 but substituting 4-(2- propyl)phenol for 4-trifluoromethoxyphenol, the title compound was obtained as a white foam (233 mg). !H NMR (300 MHz, Acetone-d6) δ 8.08 (d, IH), 7.95 (m, 2H), 7.83 (dd, IH), 7.41 (d, IH), 7.35-6.69 (m, 11H), 4.53 (t, IH), 3.48 (m, 2H), 2.90 ( , IH), 1.23 (d, 3H). EXAMPLE 12 4-{ 2-[3,4-BIS(DIFLUOROMETHOXY)PHENYL]-2-{ 6-[4- (DIMETHYLSULFONYLAMINO)PHENOXY]-3-PYRΓDYL}ETHYL}PYRΓDΓ E- N-OXIDE Step 1 4-{ 2-|3,4-Bis(dif]uoromethoxy)phenyn-2-{6-r4-(dimethylsulfonylamino)phenoxyl-3- pyridyl jethyl Ipyridine To a 0 °C solution of 4-{2-[3,4-bis(difluoromethoxy)phenyl]-2-[6-(4- aminophenoxy)-3-pyridyl]ethyl }pyridine from Example 7, Step 1 (817 mg, 1.64 mmol) in 25 mL of CH2CI2, was added 1.1 mL (8.2 mmol) of Et3N followed by 0.44 mL (5.74 mmol) of methylsulfonyl chloride. The resulting solution was stiπed 1 h at 0 °C, quenched with water and diluted with ethyl acetate. The organic layer was washed with brine, dried over MgSO4 and concentrated under reduced pressure. The residue was purified by flash chromatography on silica gel (100% Ethyl acetate) to afford the disulfonamide as an amoφhous solid (807 mg, 75 %). Step 2 4-{ 2-|3,4-Bis(difluoromethoxy)phenyl1-2-{6-r4-(dimethylsulfonylamino)phenoxyl-3- pyridyl } ethyl } pyridine-N-oxide The procedure for the oxidation of the pyridine group described in Example 1, Step 6 was applied using the product of Step 1 above as starting material. The title compound was obtained as a foam (725 mg, 88%). [ H NMR (500 MHz, Acetone-d6) δ 8.13 (d, IH), 7.94 (d, 2H), 7.90 (dd, IH), 7.50 (m, 2H), 7.42 (d, IH), 7.34 (m, IH), 7.28 (d, IH), 7.20-7.16 (m, 4H), 7.00 (d, IH), 6.96 (t, IH), 6.93 (t, IH), 4.57 (t, IH), 3.49 (m, 2H), 3.48 (s, 6H). EXAMPLE 13 4-{ 2-[3,4-BIS(DIFLUOROMETHOXY)PHENYL]-2-{ 6-[(4-HYDROXYMETHYL- 3-CARBOXYL)PHENOXY]3-PYRIDYL}ETHYL}PYRIDINE-N-OXIDE SODIUM SALT Step 1 4-{ 2-[3,4-Bιs(dιfluoromethoxy)phenyll-2-F6-(l,2-dihvdro-l-ιsobenzofuranone-6- oxy)3-pyndyllethyl lpyridine-N-oxide To a solution of intermediate 3 (104 mg, 0.214 mmol) in 0.2 mL of pyridme, was added 45 mg of (0.3 mmol) of phenol followed by 45 mg of K2CO3 and 3 mg of CuO. The mixture was stirred at 170 °C for 3 h cooled down to room temperature and punfied directly by flash chromatography on silica gel (10% EtOH/ethyl acetate) to afford 47 mg of the title compound. Step 2 4-{ 2-[3,4-Bιs(difluoromethoxy)phenyll-2-{6-r(4-hydroxymethyl-3- carboxyl)phenoxyl3-pyndyl }ethyl lpyndιne-N-oxιde sodium salt To a solution of lactone (23 mg, 0.041 mmol) from Step 1 above in 1 mL of ethanol, was added 0.041 mL of a 1 N solution of NaOH. The reaction was stiπed 3 h at room temperature and 1 mL of water was added. The mixture was filtered and frozen dry to afford 22 mg of the title compound. EXAMPLE 14 4-{2-[3,4-BIS(DIFLUOROMETHOXY)PHENYL]-2-[6-(BENZYLOXY)3- PYRIDYL]ETHYL}PYR]DF E-N-OXIDE Following the procedure described in Example 1 but substituting benzyl alcohol for 4-trifluoromethoxyphenol, the title compound was obtained as a white foam (290 mg). J H NMR (500 MHz, Acetone-dό) δ 8.11 (d, IH), 7.95 (m, 2H), 7.73 (dd, IH), 7.45-7.25 (m, 8H), 7.18 (m, 2H), 6.96 (t, IH), 6.93 (t, IH), 6.77 (d, IH), 5.33 (s, 2H), 4.49 (t, IH), 3.45 (m, 2H). EXAMPLE 15 4-{ 2-[3,4-BIS(DΓFLUOROMETHOXY)PHENYL]-2-[6-(1-PHENYLETHOXY)3- PYRID YLjETHYL } PYRIDINE-N-OXIDE Following the procedure described in Example 1 but substituting (±)-l- phenylethanol for 4-tnfluoromethoxyphenol, the title compound was obtained as a white foam (54 mg). l H NMR (500 MHz, Acetone-d6) δ 8.01 (m, IH), 7.92 (m, 2H), 7.70 (m, IH), 7.42-7.37 (m, 3H), 7.32-7.28 (m, 3H), 7.25-7.20 (m, 2H), 7.15 (m, 2H), 6.93 (m, 2H), 6.75 (d, IH), 6.17 (m, IH), 4.44 (m, IH), 3.42 (m, 2H), 1.54 (d, 3H). EXAMPLE 16 4-{ 2-[3,4-BIS(DIFLUOROMETHOXY)PHENYL]-2-[6-(3,4- DIFLUOROBENZYLOXY)3-P YRID YL]ETHYL ) PYRIDINE-N-OXIDE Following the procedure descnbed in Example 1 but substituting 3,4- difluorobenzyl alcohol for 4-tπfluoromethoxyphenol, the title compound was obtained } H NMR (500 MHz, Acetone-d6) δ 8.12 (d, IH), 7.96 (m, 2H), 7.77 (dd, IH), 7.41 (m, 2H), 7.34-7.26 (m, 4H), 7.19 (m, 2H), 6.97 (t, IH), 6 94 (t, IH), 6.79 (d, IH), 5.30 (m, 2H), 4.51 (t, IH), 3.48 (m, 2H). EXAMPLE 17 4- { 2- [3 ,4-BIS (DEFLUOROMETHOX Y)PHEN YL]-2- [6-(4- METHYLSULFONYLBENZYLOXY)3-PYRIDYL]ETHYL} PYRIDINE-N-OXIDE Step 1 2-r4-(methylthιo)benzyloxyl-5-bromopyndιne To a solution of 2,5-dιbromopyndιne (5.0 g, 21.1 mmol) in 75.0 mL of toluene, was added 4.2 g (27.43 mmol) of 4-(methylthιo)benzyl alcohol, 2 8 g (50.64 mmol) of KOH and 400 mg (0.054 mmol) of 18-crown-6. The solution was heated at refluxing temperature with a Dean-Stark apparatus for 3 h, cooled down to room temperature and rotovaped down to dryness. The residue was diluted with water/CHCl3 and the organic phase was washed with bnne, dried over MgSO4 and concentrated under reduced pressure. The solid residue was washed with Et2θ/hexane and filtered to afford 3.6 g (55%) of bromide as a pale yellow solid Step 2 [3,4-Bis(difluoromethoxy)phenyll-{6-r4-(methylthio)benzyloxyl-3-pyridyU methanol To a -78 °C solution of bromopyridine from Step 1 above (1.0 g, 3.22 mmol) in 10 mL of THF, was added 1.7 mL (3.65 mmol) of a 2.1 M solution of n- BuLi. The solution was stirred 15 minutes followed by the addition of 7 mL of a THF solution of 3,4-bis(difluoromethoxy)benzaldehyde (512 mg, 2.15 mmol). The resulting solution was stirred 30 minutes at -78 °C, quenched with a 25% NH4OAC solution and diluted with ethyl acetate. The organic layer was washed with brine, dried over MgSO4 and concentrated under reduced pressure. The residue was purified by flash chromatography on silica gel (25% Ethyl acetate/hexane) to afford the alcohol as an oil (380 mg, 30%). Step 3 [3,4-Bis(difluoromethoxy)phenyn-[6-(4-methylsulfonylbenzyloxy)3-pyridvnmethanol To a solution of methyl sulfide from Step 2 above (380 mg, 0.97 mmol) in a mixture of 10 mL of CH2CI2 and 1.0 mL of MeOH, was added MMPP (1.4 g, 2.82 mmol) in one portion. The mixture was stirred 1.5 h at room temperature, quenched with a 25% NH4OAC solution and diluted with ethyl acetate. The organic layer was washed with brine, dried over MgSO4 and concentrated under reduced pressure. The residue was purified by flash chromatography on silica gel (60% Ethyl acetate/hexane) to afford the methyl sulfone as an oil (384 mg, 93%). Step 4 |3,4-Bis(difluoromethoxy)phenyll-[6-(4-methylsulfonylbenzyloxy)3- pyridyllchloromethane The procedure for the formation of the chloride described in Example 1, Step 3 was applied using the product of Step 3 above as starting material. The chloride obtained was used directly for the next step without any purification. Step 5 4-{ l-Carbethoxy-2-r3,4-bis(difluoromethoxy)phenyll-2-F6-(4- methylsulfonylbenzyloxy)-3-pyridyllethyl Ipyridine The procedure for the alkylation with ethyl 4-pyndylacetate described in Example 1, Step 4 was applied using the product of Step 4 above as starting matenal. The ethyl ester obtained was used directly for the next step without any punfication. Step 6 4-{ 2-r3,4-Bιs(dιfluoromethoxy)phenyl1-2-[6-(4-methylsulfonylbenzyloxy)3- pyndyll ethyl I pyndine The procedure for the hydrolysis/decarboxylation descnbed in Example 1, Step 5 was applied using the product of Step 5 above as starting matenal. The pyndine was obtained as an oil (340 mg, 65% for 3 steps). Step 7 4-{ 2-[3,4-Bιs(dιfluoromethoxy)phenyl1-2-r6-(4-methylsulfonylbenzyloxy)3- pyndyllethyl )pyndιne-N-oxιde The procedure for the oxidation of the pyndine group descnbed in Example 1, Step 6 was applied using the product of Step 6 above as starting matenal. The title compound was obtained as a foam (320 mg, 92%). { H NMR (500 MHz, Acetone-d6) δ 8.10 (d, IH), 7.96-7.92 (m, 4H), 7.77 (dd, IH), 7.68 (d, 2H), 7.41 (d, IH), 7.33 (dd, IH), 7.27 (d, IH), 7 18 (d, 2H), 6.97 (t, IH), 6 94 (t, IH), 6.84 (d, IH), 5.46 (s, 2H), 4 50 (t, IH), 3.46 (m, 2H), 3.12 (s, 3H). EXAMPLE 18 (ENANTIOMER-L )-4-{ 2-[3,4-BIS(DIFLUOROMETHOXY)PHENYL]-2-[6-(3,5- DΓFLUOROBENZYLOXY)3-PYRΓDYL]ETHYL}PYRIDΓNE Following the procedure descnbed in Example 1, Step 1-5 but substituting 3,5-difluorobenzyl alcohol for 4-tnfluoromethoxyphenol, the racemic title compound was obtained as a white foam. The mixture was then resolved with a preparative column chiralpak AD, 17% z-PrOH/hexane, 70 mlJmin 650 mg of Example 18 were obtained as the fast elutmg enantiomer with a retention time of 38 minutes. !H NMR (400 MHz, Acetone-d6) δ 8 36 (dd, 2H), 8.10 (d, IH), 7 78 (dd, IH), 7.40 (s, IH), 7 32 (dd, IH), 7.25 (d, IH), 7 18 (dd, 2H), 7.07 (m, 2H), 6.96 (t, IH), 6.95 (m, IH), 6.92 (t, IH), 6.79 (d, IH), 5 35 (s, 2H), 4.55 (t, IH), 3 48 (dd, 2H). EXAMPLE 19 (ENANTIOMER-2)-4-{ 2-[3,4-BIS(DIFLUOROMETHOXY)PHENYL]-2-[6-(3,5- DΓFLUOROBENZYLOXY)3-PYRΓD YLJETHYL } PYRΓDINE Following the procedure descnbed in Example 1, Step 1-5 but substituting 3,5-difluorobenzyl alcohol for 4-tnfluoromethoxyphenol, the racemic title compound was obtained as a white foam. The mixture was then resolved with a preparative column: chiralpak AD, 35% /-PrOH/hexane, 75 mlJmin. 640 mg of Example 19 were obtained as the slow eluting enantiomer with a retention time of 45 minutes. !H NMR (400 MHz, Acetone-d6) δ 8.36 (dd, 2H), 8.10 (d, IH), 7.78 (dd, IH), 7.40 (s, IH), 7.32 (dd, IH), 7.25 (d, IH), 7 18 (dd, 2H), 7.07 (m, 2H), 6.96 (t, IH), 6.95 (m, IH), 6.92 (t, IH), 6.79 (d, IH), 5.35 (s, 2H), 4.55 (t, IH), 3 48 (dd, 2H). EXAMPLE 20 (ENANTIOMER- 1 )-4- { 2- [3 ,4-BIS(DIFLUOROMETHOXY)PHENYL] -2-[6-(3 ,5- DIFLUOROBENZYLOXY)3-PYRIDYL]ETHYL}PYRΓDINE-N-OXIDE The procedure for the oxidation of the pyndine group descnbed in Example 1 , Step 6 was applied using the product of Example 18 above as starting matenal. The title compound was obtained as a foam (600 mg) iH NMR (400 MHz, Acetone-d6) δ 8.13 (d, IH), 7.97 (d, 2H), 7.78 (dd, IH), 7.41 (d, IH), 7 34 (dd, IH), 7.27 (d, IH), 7.20 (d, 2H), 7.09 (dd, 2H), 6.98 (t, IH), 6.95 (t, IH), 6.94 (m, IH), 6.85 (d, IH), 5.36 (s, 2H), 4.53 (t, IH), 3 47 (dd, 2H). EXAMPLE 21 (ENANTIOMER-2)-4-{ 2-[3,4-BIS(DIFLUOROMETHOXY)PHENYL]-2-[6-(3,5- DΓFLUOROBENZYLOXY)3-PYRΓD YLJETHYL } PYRΓDΓNΈ-N-OXΓDE The procedure for the oxidation of the pyndine group descnbed in Example 1, Step 6 was applied using the product of Example 19 above as starting matenal. The title compound was obtained as a foam (600 mg). *H NMR (400 MHz, Acetone-d6) δ 8.13 (d, IH), 7.97 (d, 2H), 7.78 (dd, IH), 7.41 (d, IH), 7.34 (dd, IH), 7.27 (d, IH), 7.20 (d, 2H), 7.09 (dd, 2H), 6.98 (t, IH), 6.95 (t, IH), 6.94 (m, IH), 6.85 (d, IH), 5.36 (s, 2H), 4.53 (t, IH), 3.47 (dd, 2H). EXAMPLE 22 4-{ 2-[3,4-BIS(DIFLUOROMETHOXY)PHENYL]-2-{ 6-[2-METHYL-2-(4- FLUOROPHENYL)PROPYLOXY] 3-P YRID YL } ETHYL } PYRΓDP E Step 1 2-Methyl-2-(4-fluorophenyl)propanol To a 0 °C solution of methyl 4-fluorophenylacetate (37 mmol) in 80 mL of THF was added 83 mmol of a 1 0 M solution of NaHMDS in THF. The solution was stirred 35 miutes at 0 °C and 1 12 mmol od Mel were added The reaction was stiπed ovemight at room temperature and quenched at 0 °C with a saturated solution of NH4CI. The aqueous layer was extracted with Et2θ and the combined organic layers were washed with bnne, dned over MgSO4 and concentrated under reduced pressure. The residue was punfied by flash chromatography on silica gel (10% Et2θ/hexane) to afford the ester methyl 2-methyl- 2-(4-fluorophenyl) propanoate This ester (3 1 g) was then dissolved in 60 mL of THF and treated at 0 °C with 8 mL of a LiAlH4 solution. The reaction was stirred 30 minutes at 0 °C and quenched with a saturated solution of NH4CI The aqueous layer was extracted with ethyl acetate and the combined organic layers were washed with bnne, dned over MgSO4 and concentrated under reduced pressure The residue was punfied by flash chromatography on silica gel (40% Et2θ/hexane) to afford 2.7 g (100%) of alcohol. Step 2 2-[2-methyl-2-(4-fluorophenyl)propyloxyl-5-bromopyndιne Following the procedure descnbed in Example 17, Step 1 but substituting 2-methyl-2-(4-fluorophenyl)propanol From Step 1 above for 4- (methylthιo)benzyl alcohol, the desired bromopyndme was obtained in 90% yield Step 3 [3,4-Bιs(dιfluoromethoxy)phenyl1-<6-[2-methyl-2-(4-fluorophenyl)propyloxy1-3- pyndyl l methanol The coupling procedure described in Example 17, Step 2 was applied using the product of Step 2 above as starting matenal. The alcohol was obtained in 45% yield. Step 4 r3,4-Bιs(dιfluoromethoxy)phenyl1-{6-r2-methyl-2-(4-fluorophenyl)propyloxyl-3- pyndyUchloromethane The procedure for the formation of the chloride descnbed in Example 1, Step 3 was applied using the product of Step 3 above as starting material. The chloride obtained was used directly for the next step without any punfication. Step 5 4-{ l-Carbethoxy-2-r3,4-bιs(dιflυoromethoxy)phenvn-2-{6-r2-methyl-2-(4- fluorophenyl)propyloxyl-3-pyndyl jethyl Ipyridine The procedure for the alkylation with ethyl 4-pyndyl acetate descnbed in Example 1, Step 4 was applied using the product of Step 4 above as starting material. The ethyl ester obtained was used directly for the next step without any punfication. Step 6 4-{ 2-r3.4-Bιs(dιfluoromethoxy)phenvn-2-{ 6-|2-methyl-2-(4- fluorophenyl)propyloxyl3-pyrιdyl jethyl j pyndine The procedure for the hydrolysis/decarboxylation descnbed in Example 1, Step 5 was applied using the product of Step 5 above as starting matenal. 641 mg of the title compound were obtained (58%, 3 Steps). iH NMR (400 MHz, Acetone-d6) δ 8.36 (d, 2H), 8.06 (s, IH), 7.69 (dd, IH), 7.49-7.46 (m, 2H), 7.38 (s, IH), 7.29 (q, 2H), 7.17 (d, 2H), 7.04 (t, 2H), 6.94 (t, IH), 6.92 (t, IH), 6.64 (d, IH), 4.52 (t, IH), 4.26 (s, 2H), 3.45 (d, 2H), 1.39 (s, 6H). EXAMPLE 23 4-{2-[3,4-BIS(DIFLUOROMETHOXY)PHENYL]-2-{6-[2-METHYL-2-(4- FLUOROPHENYL)PROPYLOXY] 3-PYRIDYL } ETHYL } PYRΓDPNE-N-OXIDE The procedure for the oxidation of the pyridine group described in Example 3 was applied using the product of Example 22 above as starting material. The title compound was obtained as a foam (157 mg, 62%). l R NMR (400 MHz, Acetone-d6) δ 8.06 (d, IH), 7.93 (d, 2H), 7.67 (dd, IH), 7.50-7.47 (m, 2H), 7.38 (s, IH), 7.32 (q, 2H), 7.17 (d, 2H), 7.04 (t, 2H), 6.95 (t, IH), 6.92 (t, IH), 6.65 (d, IH), 4.48 (t, IH), 4.27 (s, 2H), 3.44 (dd, 2H), 1.40 (s, 6H). EXAMPLE 24 4-{ 2-[3,4-BIS(DIFLUOROMETHOXY)PHENYL]-2-{6-[2-(4- FLUOROPHEN YL)ETHOX Y] 3 -P YRID YL } ETHYL } PYRIDINE Following the procedure described in Example 22, Step 2-6 but substituting 2-(4-fluorophenyl)ethanol for 2-methyl-2-(4-fluorophenyl)propanol , 820 mg of the title compound were obtained. !H NMR (400 MHz, Acetone-d6) δ 8.39 (d, 2H), 8.09 (s, IH), 7.71 (dd, IH), 7.39 (s, IH), 7.35 (m, 3H), 7.25 (d, IH), 7.20 (m, 2H), 7.05 (m, 2H), 6.85 (t, IH), 6.83 (t, IH), 6.66 (d, IH), 4.55 (t, IH), 4.42 (t, 2H), 3.42 (d, 2H), 3.02 (t, 2H). EXAMPLE 25 4-{2-[3,4-BIS(DIFLUOROMETHOXY)PHENYL]-2-{6-[2-(4- FLUOROPHENYL)ETHOXY]3-PYRID YL } ETHYL } PYR1DINE-N -OXIDE The procedure for the oxidation of the pyridine group described in Example 3 was applied using the product of Example 24 above as starting material. The title compound was obtained as a foam (137 mg, 66%). iH NMR (400 MHz, Acetone-dό) δ 8.08 (s, IH), 7.93 (d, 2H), 7.70 (dd, IH), 7.38 (s, IH), 7.35 ( , 3H), 7.28 (d, IH), 7.18 (d, 2H), 7.03 (t, 2H), 6.95 (t, IH), 6.92 (t, IH), 6.67 (d, IH), 4.48 (t, IH), 4.42 (t, 2H), 3.45 (dd, 2H), 3.01 (t, 2H). EXAMPLE 26 4-{ 2-[3,4-BIS(DIFLUOROMETHOXY)PHENYL]-2-[6-(4- TRΓFLUOROMETHYLBENZYLOXY)3-PYRID YL]ETHYL } PYRΓDΓNE-N-OXIDE Following the procedure described in Example 1 but substituting 4- trifluoromethylbenzyl alcohol for 4-trifluoromethoxyphenol, 427 mg of the title compound was obtained as an oil. *H NMR (500 MHz, Acetone-dό) δ 8.12 (d, IH), 7.98 (m, 2H), 7.78 (dd, IH), 7.70 (d, 2H), 7.65 (d, 2H), 7.43 (d, IH), 7.33 (m, IH), 7.28 (d, IH), 7.20 (m, 2H), 7.00 (t, IH), 6.96 (t, IH), 6.83 (d, IH), 5.43 (m, 2H), 4.52 (t, IH), 3.47 (m, 2H). EXAMPLE 27 4-{ 2-[3,4-BIS(DIFLUOROMETHOXY)PHENYL]-2-[6-(4- TRΓFLUOROMETHOXYBENZYLOXY)3-PYRΓD YLJETHYL } PYRΓDΓNE-N- OXIDE Following the procedure described in Example 1 but substituting 4- trifluoromethoxybenzyl alcohol for 4-trifluoromethoxyphenol, 480 mg of the title compound was obtained as an oil. H NMR (500 MHz, Acetone-d6) δ 8.12 (d, IH), 7.96 (m, 2H), 7.76 (dd, IH), 7.57 (d, 2H), 7.41 (s, IH), 7.32 (m, 3H), 7.27 (d, IH), 7.19 (d, 2H), 6.98 (t, IH), 6.94 (t, IH), 6.79 (d, IH), 5.36 (m, 2H), 4.51 (t, IH), 3.46 (m, 2H). EXAMPLE 28 4- { 2-[3,4-BIS(DIFLUOROMETHOXY)PHENYL]-2-[6-( 1 , 1 -DIMETHYL-2- PHENYLETHOXY)3-PYRIDYL]ETHYL} PYRIDINE-N-OXIDE Step 1-5 4-{ 2-F3,4-Bis(difluoromethoxy)phenyn-2-r6-(l ,l-dimethyl-2-phenylethoxy)3- pyridvUethyl Ipyridine Following the procedure described in Example 22, Step 2-6 but substituting l,l-dimethyl-2-phenylethanol for 2-methyl-2-(4-fluorophenyl)propanol the pyridine was obtained. Step 6 4-{ 2-[3,4-Bιs(dιfluoromethoxy)phenvn-2-[6-(l,l-dιmethyl-2-phenylethoxy)3- pyndyllethyl jpyndme-N-oxide The procedure for the oxidation of the pyndine group described Example 3 was applied using the product of Step 5 above as starting matenal. The title compound was obtained as a foam (175 mg). ] H NMR (400 MHz, Acetone-d6) δ 8.12 (d, IH), 7.95 (d, 2H), 7.67 (dd, IH), 7.40 (d, IH), 7.33 (dd, IH), 7.26 (d, IH), 7.12-7.23 (m, 7H), 6.96 (t, IH), 6.92 (t, IH), 6.60 (d, IH), 4.47 (t, IH), 3.46 (dd, 2H), 3.23 (d, 2H), 1.49 (s, 6H). EXAMPLE 29 4-{2-[3,4-BIS(DIFLUOROMETHOXY)PHENYL]-2-{ 6-[2-THIENYLMETHOXY]3- P YRID YL } ETHYL } PYRIDINE-N-OXIDE Step 1-5 4-{ 2-r3,4-Bιs(dιfluoromethoxy)phenyl1-2-{ 6-[2-thιenylmethoxy13- pyndyl jethyl j pyndine Following the procedure descnbed in Example 22 , Step 2-6 but substituting (2-thιenyl)methanol for 2-methyl-2-(4-fluorophenyl)propanol , the pyndine was obtained. Step 6 4-{ 2-[3,4-Bιs(dιfluoromethoxy)phenyll-2-{ 6-f2-thιenylmethoxyl3- pyndyl jethyl jpyndine-N-oxide The procedure for the oxidation of the pyndine group descnbed in Example 3 was applied using the product of Step 5 above as starting matenal. The title compound was obtained as a foam (35 mg). !H NMR (400 MHz, Acetone-dό) δ 8.14 (d, IH), 7.95 (d, 2H), 7.73 (dd, IH), 7.43-7.41 (m, 2H), 7.31 (q, 2H), 7.20-7.15 (m, 3H), 7.00-6.97 (m, IH), 6.97 (t, IH), 6.94 (t, IH), 6.72 (d, IH), 5.50 (s, 2H), 4.51 (t, IH), 3.52-3.42 (m, 2H). EXAMPLE 30 4- { 2-[3,4-BIS(DIFLUOROMETHOXY)PHENYL]-2- { 6-[ 1 -METHYL- 1 -(4- FLUOROPHEN YL)ETHOXY]3-PYRIDYL } ETHYL } PYRIDFNE Following the procedure descnbed in Example 22, Step 2-6 but substituting 1 -methyl- l-(4-fluorophenyl)ethanol (Prepared by the addition of MeMgCl on 4-fluoroacetophenone) for 2-methyl-2-(4-fluorophenyl)propanol, 500 mg of the title compound were obtained. H NMR (400 MHz, Acetone-d6) δ 8.33 (d, 2H), 7.80 (d, IH), 7.65 (dd, IH), 7.43-7.38 (m, 2H), 7.33 (s, IH), 7.26 (dd, IH), 7.22 (d, IH), 7.10 (d, 2H), 7.00 (t, IH), 6.92 (t, IH), 6.91 (t, IH), 6.72 (d, IH), 4.39 (t, IH), 3.40 (m, 2H), 1.81 (s, 6H). EXAMPLE 31 4- { 2-[3,4-BIS(DIFLUOROMETHOXY)PHENYL]-2- { 6-[ 1 -METHYL- 1 -(4- FLUOROPHENYL)ETHOXY]3-PYRΓDYL JETHYL JPYRΓDΓNE-N-OXΓDE The procedure for the oxidation of the pyndine group descnbed in Example 3 was applied using the product of Example 30 above as starting matenal. The title compound was obtained as a foam (53 mg, 19%). l U NMR (400 MHz, Acetone-d6) δ 7.92 (d, 2H), 7.84 (d, IH), 7.44- 7.38 (m, 2H), 7.33 (s, IH), 7.29 (dd, IH), 7.22 (d, IH), 7.12 (d, 2H), 7.05 (t, 2H), 6.95 (t, IH), 6.93 (t, IH), 6.74 (d, IH), 4.32 (t, IH), 3.45-3.32 (m, 2H), 1.82 (s, 6H). EXAMPLE 32 4-{ 2-[3,4-BIS(DIFLUOROMETHOXY)PHENYL]-2-[6-(4- FLUOROBENZYLOXY)3-PYRID YLjETHYL } PYRIDINE-N-OXIDE Following the procedure descnbed in Example 1 but substituting 4- fluorobenzyl alcohol for 4-tnfluoromethoxyphenol, 475 mg of the title compound were obtained. iH NMR (400 MHz, Acetone-d6) δ 8.11 (d, IH), 7.94 (d, 2H), 7.74 (dd, IH), 7.47 (dd, 2H), 7.40 (d, IH), 7.33 (dd, IH), 7.27 (d, IH), 7.18 (d, 2H), 7.08- 7.13 (m, 2H), 6.96 (t, IH), 6.93 (t, IH), 6.77 (d, IH), 5.30 (s, 2H), 4.50 (t, IH), 3.47 (dd, 2H). EXAMPLE 33 4-{ 2-[3,4-BIS(DIFLUOROMETHOXY)PHENYL]-2-[6-(4- CHLOROBENZYLOXY)3-PYRIDYL]ETHYL } PYRΓDINE-N-OXIDE Following the procedure descnbed in Example 1 but substituting 4- chlorobenzyl alcohol for 4-tnfluoromethoxyphenol, 500 mg of the title compound were obtained. iH NMR (400 MHz, Acetone-d6) δ 8.11 (d, IH), 7.94 (d, 2H), 7.75 (dd, IH), 7.46 (d, 2H), 7.36-7.41 (m, 3H), 7.33 (dd, IH), 7.27 (d, IH), 7.18 (d, 2H), 6.97 (t, IH), 6.93 (t, IH), 6.77 (d, IH), 5.31 (s, 2H), 4.49 (t, IH), 3.46 (dd, 2H). EXAMPLE 34 4- { 2- [3 ,4-BIS (DIFLUOROMETHOXY)PHEN YL] -2- { 6- [ 1 ,2-DIH YDRO- 1 - ISOBENZOFURANONE-6-OXY]3-PYRIDYL } ETHYL} PYRIDLNΕ-N-OXIDE To a solution of intermediate 3 (104 mg, 0.214 mmol) in 0.2 mL of pyndine, was added 45 mg of (0.3 mmol) of 6-hydroxyl-l,2-dιhydro-l- lsobenzofuranone followed by 45 mg of K2CO3 and 3 mg of CuO. The mixture was stiπed at 170 °C for 3 h cooled down to room temperature and purified directly by flash chromatography on silica gel (10% EtOH/ethyl acetate) to afford 47 mg of the title compound. l H ΝMR (500 MHz, Acetone-d6) δ 8.11 (s, IH), 8.00-7.90 (m, 3 H), 7 69 (d, IH), 7.55-7.47 (m, 2H), 7.44 (s, IH), 7.34 (d, IH), 7.28 (d, IH), 7.20 (d, 2H), 7.03 (d, IH), 6.97 (t, large J, IH), 6.94 (t, large J, IH), 5.40 (s, 2H), 4.57 (t, IH), 3 50 (d, 2H). PREPARATION OF INTERMEDIATES INTERMEDIATE 1 [3,4-BIS(DIFLUOROMETHOXY)PHENYL]-(6-BROMO-3- PYRΓDYL)METHANONE Step 1 r3,4-Bis(difluoromethoxy)phenyl1-(6-bromo-3-pyndyl)methanol To a -78 °C suspension of 2,5-dibromopyridine (1 1.4 g, 48 0 mmol) in 300 mL of Et2θ, was added 40.0 mL (48.0 mmol) of a 1.2 N solution of n- butylhthium in hexane over 10 minutes. The orange mixture was stiπed (Mechanical stiπer) 10 minutes at -78 °C followed by the addition over 5 minutes of a precooled solution of bιs(dιfluoromethoxy)benzaldehyde (9.6 g, 40.0 mmol) in 60 mL of Et2θ This red solution was stiπed 1 h at -78 °C and slowly poured into a saturated aqueous solution of NH4CI. The aqueous layer was extracted with ethyl acetate and the combined organic phases were washed with brine, dry over MgSO4 and concentrated under reduced pressure. The residue was purified by chromatography on silica gel (Gradient 20% to 40% ethyl acetate/hexane) to afford 8.3 g (53%) of alcohol. Step 2 f3,4-Bιs(dιfluoromethoxy)phenyll-(6-bromo-3-pyndyl)methanone To a solution of alcohol (3.96 g, 10.0 mmol) from Step 1 above in 60 mL of CH2CI2, was added 8.1 g (93.0 mmol) of Mnθ2- The resulting mixture was stirred 20 h at room temperature and filtered on ce te. the volatile were removed under reduced pressure to afford 3 48 g (88%) of ketone. ! H NMR (500 MHz, Acetone-d6) δ 8.72 (d. IH), 8.10 (dd, IH), 7.85- 7 78 (m, 3H), 7.55 (d, IH), 7.20 (t, IH), 7.12 (t, IH). INTERMEDIATE 2 4-{ 2-[3,4-BIS(DIFLUOROMETHOXY)PHENYL]-2-(6-BROMO-3- PYRΓDYL)ETHYL } PYRΓDΓNE Step 1 [3,4-Bιs(dιfluoromethoxy)phenyll-(6-bromo-3-pyndyl)chloromethane To a solution [3,4-Bιs(dιfluoromethoxy)phenyl]-(6-bromo-3- pyπdyl)methanol (15.8 g,40.0 mmol) 400 mL of CH2CI2, was added 3.8 mL (52.0 mmol) of SOC12- The solution was stirred 45 minutes at room temperature and poured into a saturated aqueous solution of NaHCO3. The aqueous layer was extracted with CH2CI2 and the combined organic layers were dry over MgSO4 and concentrated under reduced pressure. The crude chlonde was used directly for the next step without any punfication. Step 2 4-{ l-Carbethoxy-2-[3,4-bιs(dιfluoromethoxy)phenyl1-2-(6-bromo-3- pyndyl)ethyl j pyndme To a 0 °C solution of ethyl 4-pyridyl acetate (19.8 g, 120 mmol) in 500 mL of THF, was added 21.0 mL (120 mmol) of HMPA and 240 mL (120 mmol) of a 0.5 M solution KHMDS in toluene. The resulting mixture was stirred 15 minutes at room temperature followed by the addition over 10 minutes of a solution of the crude chloride from Step 1 above in 100 mL of THF The reaction was stirred 1 h at room temperature, poured into a saturated aqueous solution of NH4CI and the pH was adjusted to 7 with 1 N HCl. The aqueous layer was extracted with ethyl acetate and the combined organic phases were washed with brine, dry over MgSO4 and concentrated under reduced pressure. The residue was used directly for the next step without any punfication. Step 3 4-{ 2-r3,4-Bιs(dιfluoromethoxy)phenyl1-2-(6-bromo-3-pyndyl)ethyl }pyndme To a solution of crude ester from Step 2 above in a mixture of 540 mL of THF, 180 mL of MeOH and 180 mL of water, was added 180 mL of a 2 N solution of LiOH. The solution was stirred 1.5 h at 65 °C, cooled down to room temperature and 360 mL of 1 N HCl solution were added The mixture was rotovaped down, the residue was diluted in ethyl acetate and the organic phases was washed with bnne, dry over MgSO4 and concentrated under reduced pressure to afford 18.2 g (97%, 3 steps) of pure bromopyndme. !H NMR (500 MHz, Acetone-d6) δ 8 40 (m, 3H), 7 78 (dd, IH), 7 50 (d, IH), 7.43 (s, IH), 7.36 (dd, IH), 7.28 (d, IH), 7.20 (m, 2H), 6 95 (t, IH), 6 94 (t, IH), 4.65 (t, IH), 3 58-3.48 (m, 2H). INTERMEDIATE 3 4- { 2-[3,4-BIS(DIFLUOROMETHOXY)PHENYL]-2-(6-BROMO-3- PYRΓDYL)ETHYL } PYRΓDΓNE To a solution of intermediate 2 (2.0 g, 4.2 mmol) in a mixture of 30 mL of CH2CI2 and 3 mL of MeOH was added 1.55 g (2.5 mmol) of 80% MMPP. The reaction was stiπed at room temperature for 20 h and punfied directly by chromatography on silica gel (Gradient 3% Et3N/ethyl acetate to 30% EtOH/ethyl acetate + 3% Et3N to 40% EtOH/ethyl acetate + 3% E.3N) to afford 1.91 g (93%) of desired pyndine-N-oxide. l H NMR (500 MHz, Acetone-d6) δ 8.38 (d, IH), 7.95 (d, 2H), 7.77 (dd, IH), 7.51 (d, IH), 7.41 (s, IH), 7.35 (dd, IH), 7.29 (d, IH), 7.19 (d, 2H), 6.96 (t, IH), 6.94 (t, IH), 4.60 (t, IH), 3.57-3.47 ( , 2H).

Claims: WHAT IS CLAIMED IS: A compound represented by formula I: or a pharmaceutically acceptable salt or hydrate thereof wherein. Y represents N or N-oxide; R! and R^ are independently selected from: H, Ci-6alkyl and haloCi-6 alkyl, R and R are independently selected from H and Ci-βalkyl, or R3 and R4 attached to the same carbon atom taken together represent a carbonyl oxygen atom, or R3 and R attached to different carbon atoms considered in combination with the carbon atoms to which they are attached along with any intervening atoms and represent a saturated 5, 6 or 7 membered carbocychc nng, R5 and R6 independently represent a member selected from the group consisting of H, Cι _6alkyl, haloCi-βalkyl and CN; n represents an integer of from 0-6; Ar^ 1S se ]ected from the group consisting of: (a) thienyl, (b) thiazolyl, (c) pyπdyl, (d) phenyl and (e) naphthyl, said Ar J 1 bein g optionally substituted with 1-3 members selected from the group consisting of: (1) halo, (2) Ci-6alkoxy, (3) Cι_7alkylthιo, (4) CN, (5) Cι_6alkyl, (6) Ci-6hydroxyalkyl, (7) -CO2H, -CO2Ci-6alkyl, (8) NH(SO2Me), N(SO2Me)2, (9) SO2Me, (10) NO2, (11) Cι_6alkenyl, (12) halo Ci-6 alkyl, and (13) NH 2 , and when Arl represents a phenyl or naphthyl group with two or three substituents, two such substituents may be considered in combination and represent a 5 or 6 membered fused lactone ring. 2 A compound in accordance with claim 1 wherein R ! and R are Ci-6 alkyl or haloCi-6alkyl 3 A compound in accordance with claim 2 wherein R ! and R are selected from the group consisting of CH3, CH2F, CHF2 and CF3. 4 A compound in accordance with claim 3 wherein R ! and R2 are CHF2. 5 A compound in accordance with claim 1 wherein n is selected from 0, 1, 2 and 3. 6 A compound in accordance with claim 5 wherein n is selected from 0, 1 and 2 7. A compound in accordance with claim 1 wherein R5 and R6 are independently selected from the group consisting of: H and Cι_6 alkyl. 8. A compound in accordance with claim 7 wherein R5 and R6 represent H. 9. A compound in accordance with claim 1 wherein Arl , s selected from phenyl and naphthyl. 10. A compound in accordance with claim 9 wherein Arl , s phenyl. 11. A compound in accordance with claim 1 wherein R and R are H or Chalky]. 12. A compound in accordance with claim 11 wherein R and R4 are H or methyl. 13 A compound in accordance with claim 1 wherein: R! and R are Ci-6alkyl or haloCi-6alkyl selected from the group consisting of CH3, CH2F, CHF2 and CF3 ; n is 0, 1, 2 or 3; Arl 1S phenyl or naphthyl, R and R are H or methyl and R5 and R6 are H or Ci_6alkyl. 14. A compound in accordance with claim 13 wherein: R ! and R 2 are CHF2, and n is 0, 1 or 2. 15. A compound in accordance with claim 14 wherein: Rl and R 2 are CHF2; n is 0, 1 or 2; R3 and R are H or methyl and Arl ]S phenyl 16 A compound selected from the group consisting of: 4-{2-[3,4-Bιs(dιfluoromethoxy)phenyl]-2-{6-[4- (tπfluoromethoxy)phenoxy]3-pyndyl jethyl }pyπdιne-N-oxιde, 4-{2-[3,4-Bιs(dιfluoromethoxy)phenyl]-2-[6-(4- (methoxycarbonyl)phenoxy)3-pyndyl]ethyl j pyndine, 4-{2-[3,4-Bιs(dιπuoromethoxy)phenyl]-2-[6-(4- (methoxycarbonyl)phenoxy)3-pyndyl]ethyljpyndιne-N-oxιde, 4-{2-[3,4-Bιs(dιfluoromethoxy)phenyl]-2-{6-[4-(2-hydroxypropan-2- yl)phenoxy]3-pyndyl Jethyl } pyndine, 4-{2-[3,4-Bιs(dιfluoromethoxy)phenyl]-2-{6-[4-(2-hydroxypropan-2- yl)phenoxy]3-pyndyl jethyl }pyndme-N-oxιde, 4-{2-[3,4-Bιs(dιfluoromethoxy)phenyl]-2-[6-(4-nιtrophenoxy)3- pyndyljethyl }pyπdme-N-oxιde, 4-{2-[3,4-Bιs(dιfluoromethoxy)phenyl]-2-{6-[4- (methylsulfonylammo)phenoxy]3-pyndyl jethyl }pyndιne-N-oxιde, 4-{2-[3,4-Bιs(dιfluoromethoxy)phenyl]-2-{6-[4- (tnfluoromethyl)phenoxy]3-pyndyl jethyl }pyπdme-N-oxιde, 4-{2-[3,4-Bιs(dιfluoromethoxy)phenyl]-2-{6-[3- (methylsulfonylamιno)phenoxy]3-pyndyl jethyl }pyndιne-N-oxιde, 4-{2-[3,4-Bιs(dιfluoromethoxy)phenyl]-2-{6-[4-(2- propenyl)phenoxy]3-pyndyl jethyl }pyπdιne-N-oxιde, 4-{2-[3,4-Bιs(dιfluoromethoxy)phenyl]-2-{6-[4-(2-propyl)phenoxy]3- pyπdyl jethyl }pyndιne-N-oxιde, 4-{2-[3,4-Bιs(dιfluoromethoxy)phenyl]-2-{6-[4- (dιmethylsulfonylamιno)phenoxy]3-pyndyl jethyl }pyndιne-N-oxιde, 4-{2-[3,4-Bιs(dιfluoromethoxy)phenyl]-2-{6-[(4-hydroxymethyl-3- carboxyl)phenoxy]3-pyndyl jethyl }pyndιne-N-oxιde sodium salt, 4-{2-[3,4-Bιs(dιfluoromethoxy)phenyl]-2-[6-(benzyloxy)3- pyndyl]ethyl jpyπdιne-N-oxιde, 4-{2-[3,4-Bιs(dιfluoromethoxy)phenyl]-2-[6-(l-phenylethoxy)3- pyπdyljethyl }pyndιne-N-oxιde, 4-{ 2-[3,4-Bιs(dιfluoromethoxy)phenyl]-2-[6-(3,4-dιfluorobenzyloxy)3- pyπdyljethyl }pyπdιne-N-oxιde, 4-{ 2-[3,4-Bιs(dιfluoromethoxy)phenyl]-2-[6-(4- methylsulfonylbenzyloxy)3-pyndyl]ethyl jpyπdιne-N-oxιde, (Enantiomer- 1)-4-{ 2-[3,4-Bιs(dι fluoromethoxy)phenyl]-2-[6-(3,5- dιfluorobenzyloxy)3-pyndyl]ethyl j pyndine, (Enantιomer-2)-4-{ 2-[3,4-Bιs(dιfluoromethoxy)phenyl]-2-[6-(3,5- dιfluorobenzyloxy)3-pyndyl]ethyl j pyndine, (Enantiomer- l)-4-{ 2-[3,4-Bιs(dιfluoromethoxy)phenyl]-2-[6-(3, 5- dιfluorobenzyloxy)3-pyndyl]ethyl jpyπdιne-N-oxιde, (Enantιomer-2)-4-{ 2-[3,4-Bιs(dιfluoromethoxy)phenyl]-2-[6-(3,5- dιfluorobenzyloxy)3-pyπdyl]ethyl }pyndιne-N-oxιde, 4-{2-[3,4-Bιs(dιfluoromethoxy)phenyl]-2-{6-[2-methyl-2-(4- fluorophenyl)propyloxy]3-pyπdyl jethyl jpyπdine, 4-{2-[3,4-Bιs(dιfluoromethoxy)phenyl]-2-{6-[2-methyl-2-(4- fluorophenyl)propyloxy]3-pyndyl jethyl }pyπdme-N-oxιde, 4-{2-[3,4-Bιs(dιfluoromethoxy)phenyl]-2-{6-[2-(4- fluorophenyl)ethoxy]3-pyndyl jethyl jpyπdine, 4-{2-[3,4-Bιs(dιfluoromethoxy)phenyl]-2-{ 6-[2-(4- fluorophenyl)ethoxy]3-pyπdyl jethyl }pyndιne-N-oxιde, 4-{2-[3,4-Bιs(dιfluoromethoxy)phenyl]-2-[6-(4- tnfluoromethylbenzyloxy)3-pyπdyl]ethyl }pyndιne-N-oxιde, 4-{2-[3,4-Bιs(dιfluoromethoxy)phenyl]-2-[6-(4- trιfluoromethoxybenzyloxy)3-pyπdyl]ethyl jpyndιne-N-oxιde, 4-{ 2-[3,4-Bιs(dιfluoιomethoxy)phenyl]-2-[6-(l,l-dιmethyl-2- phenylethoxy)3-pyndyl]ethyl jpyπdιne-N-oxιde, 4-{2-[3,4-Bιs(dιfluoromethoxy)phenyl]-2-[6-(2-thιenylmethoxy)3- pyπdyljethyl }pyndιne-N-oxιde, 4-{2-[3,4-Bιs(dιfluoromethoxy)phenyl]-2-{ 6-[l-methyl-l-(4- fluorophenyl)ethoxy]3-pyndyl jethyl jpyπ dine, 4-{2-[3,4-Bιs(dιfluoromethoxy)phenyl]-2-{6-[l-methyl-l-(4- fluorophenyl)ethoxy]3-pyπdyl jethyl }pyndιne-N-oxιde, 4-{2-[3,4-Bιs(dιfluoromethoxy)phenyl]-2-[6-(4-fluorobenzyloxy)3- pyndyljethyl }pyπdme-N-oxιde, 4-{2-[3,4-Bιs(dιfluoromethoxy)phenyl]-2-[6-(4-chlorobenzyloxy)3- pyndyljethyl }pyndme-N-oxιde, and 4-{2-[3,4-Bis(difluoromethoxy)phenyl]-2-{6-[l,2-dihydro-l- isobenzofuranone-6-oxy]3-pyridyl jethyl }pyridine-N-oxide; or a pharmaceutically acceptable salt or hydrate thereof. 17. A compound in accordance with claim 1 selected from one of the following tables: 18. A pharmaceutical composition that is comprised of a compound of formula (I) or a pharmaceutically acceptable salt or hydrate thereof, as defined in any one of claims 1 to 17 in combination with a pharmaceutically acceptable carrier. 19. A method of treating or preventing a disease or condition mediated by PDE 4, comprising administering to a mammalian patient in need thereof, a compound in accordance with claim 1 in an amount that is effective to treat or prevent said disease or condition. 20. A method in accordance with claim 19 wherein the disease or condition is selected from the group consisting of: asthma, inflammed lung associated with asthma, cystic fibrosis, inflammatory airway disease, chronic bronchitis, eosinophilic granuloma, psoriasis, other benign and malignant proliferative skin diseases, endotoxic shock, septic shock, ulcerative colitis, Crohn's disease, reperfusion injury of the myocardium or brain, inflammatory arthritis, chronic glomerulonephritis, atopic dermatitis, urticaria, adult respiratory distress syndrome, diabetes insipidus, allergic rhinitis, allergic conjunctivitis, vernal conjunctivitis, arterial restenosis, atherosclerosis, neurogenic inflammation, pain, cough, rheumatoid arthritis, ankylosing spondylitis, transplant rejection and graft versus host disease, hypersecretion of gastric acid, bacterial, fungal or viral induced sepsis or septic shock, inflammation and cytokine-mediated chronic tissue degeneration, osteoarthritis, cancer, cachexia, muscle wasting, depression, memory impairment, tumour growth and cancerous invasion of normal tissues. 21. A method of treating or preventing asthma in a mammalian patient in need of such treatment or prevention, comprising administering to said patient a compound in accordance with claim 1 in an amount that is effective for treating or preventing asthma. 22. A compound of formula (I), or a pharmaceutically acceptable salt or hydrate thereof, as defined in any one of claims 1 to 17 for use in treating or preventing a disease or condition mediated by PDE 4. 23. Use of a compound of formula (I), or a pharmaceutically acceptable salt or hydrate thereof, as defined in any one of claims 1 to 17, for use in the manufacture of a medicament for treating or preventing a disease or condition mediated by PDE 4. 24. A phosphodiesterase IV (PDE 4) inhibitor pharmaceutical composition comprising an acceptable PDE 4 inhibiting amount of a compound of formula (I), as defined in any one of claims 1 to 17, or a pharmaceutically acceptable salt or hydrate thereof, in association with a pharmaceutically acceptable carrier.

Inventors: FRENETTE RICHARD, FRIESEN RICHARD, GIRARD MARIO, GIRARD YVES, GODBOUT CEDRICKX, GUAY DANIEL, HAMEL PIERRE, PERRIER HELENE, FRENETTE, RICHARD, FRIESEN, RICHARD, GIRARD, MARIO, GIRARD, YVES, GODBOUT, CEDRICKX, GUAY, DANIEL, HAMEL, PIERRE, Perrier, Helene
Applicants: FRENETTE RICHARD, FRIESEN RICHARD, GIRARD MARIO, GIRARD YVES, GODBOUT CEDRICKX, GUAY DANIEL, HAMEL PIERRE, MERCK FROSST CANADA INC, PERRIER HELENE, FRENETTE, RICHARD, FRIESEN, RICHARD, GIRARD, MARIO, GIRARD, YVES, GODBOUT, CEDRICKX, GUAY, DANIEL, HAMEL, PIERRE, MERCK FROSST CANADA & CO., Perrier, Helene
Application year: 2000
Main classification: C07D213
IPC codes: A61K31, A61P9, A61P11, A61P17, A61P19, A61P29, A61P35, A61P43, C07D213, C07D405, C07D409, C07D417