Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C401/00—Irradiation products of cholesterol or its derivatives; Vitamin D derivatives, 9,10-seco cyclopenta[a]phenanthrene or analogues obtained by chemical preparation without irradiation
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
  • A61P19/00—Drugs for skeletal disorders
  • A61P19/08—Drugs for skeletal disorders for bone diseases, e.g. rachitism, Paget's disease
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
  • A61P19/00—Drugs for skeletal disorders
  • A61P19/08—Drugs for skeletal disorders for bone diseases, e.g. rachitism, Paget's disease
  • A61P19/10—Drugs for skeletal disorders for bone diseases, e.g. rachitism, Paget's disease for osteoporosis
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
  • A61P3/00—Drugs for disorders of the metabolism
  • A61P3/02—Nutrients, e.g. vitamins, minerals
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
  • A61P3/00—Drugs for disorders of the metabolism
  • A61P3/12—Drugs for disorders of the metabolism for electrolyte homeostasis
  • A61P3/14—Drugs for disorders of the metabolism for electrolyte homeostasis for calcium homeostasis
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
  • A61P5/00—Drugs for disorders of the endocrine system
  • A61P5/18—Drugs for disorders of the endocrine system of the parathyroid hormones
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
  • Y02P20/00—Technologies relating to chemical industry
  • Y02P20/50—Improvements relating to the production of bulk chemicals
  • Y02P20/55—Design of synthesis routes, e.g. reducing the use of auxiliary or protecting groups

Definitions

• This invention relates to methods for treating a variety of diseases using Vitamin D 3 analogs and methods for producing these analogs.
• This invention relates particularly to 3- desoxy-20-desmethyl-20-cyclopropyl vitamin D 3 analog esters and methods for producing and using the same.
• Osteoporosis is the most common form of metabolic bone disease and may be considered the symptomatic, fracture stage of bone loss (osteopenia). Although osteoporosis may occur secondary to a number of underlying diseases, 90% of all cases appear to be idiopathic. Postmenopausal women are at risk for idiopathic osteoporosis (postmenopausal or Type I osteoporosis); another particularly high risk group for idiopathic osteoporosis is the elderly of either sex (senile or Type II osteoporosis).
• Osteoporosis has also been related to corticosteroid use, immobilization or extended bed rest, alcoholism, diabetes, gonadotoxic chemo-therapy, hyperprolactinemia, anorexia nervosa, primary and secondary amenorrhea, transplant immunosuppression, and oophorectomy.
• Postmenopausal osteoporosis is characterized by fractures of the spine, while femoral neck fractures are the dominant features of senile osteoporosis.
• the mechanism by which bone is lost in osteoporotics is believed to involve an imbalance in the process by which the skeleton renews itself. This process has been termed bone remodeling. It occurs in a series of discrete pockets of activity.
• Osteoclasts bone dissolving or resorbing cells
• Osteoclasts are responsible for the resorption of a portion of bone of generally constant dimension. This resorption process is followed by the appearance of osteoblasts (bone forming cells) which then refill with new bone the cavity left by the osteoclasts.
• osteoclasts and osteoblasts function so that bone formation and bone resorption are in balance.
• an imbalance in the bone remodeling process develops which results in bone being replaced at a slower rate than it is being lost.
• this imbalance occurs to some extent in most individuals as they age, it is much more severe and occurs at a younger age in postmenopausal osteoporotics, following oophorectomy, or in iatrogenic situations such as those resulting from corticosteroid therapy or the immunosuppression practiced in organ transplantation.
• Vitamin D 3 is a critical element in the metabolism of calcium, promoting intestinal absorption of calcium and phosphorus, maintaining adequate serum levels of calcium and phosphorus, and stimulating flux of calcium into and out of bone. Vitamin D 3 is hydroxylated in vivo, with the resulting l ,25-dihydroxy metabolite being the active material. Animal studies with l,25-(OH)2 vitamin D 3 have suggested bone anabolic activity. Aerssens et al. in Calcif Tissue Int, 55:443-450 (1994) reported upon the effect of l ⁇ -hydroxy Vitamin D 3 on bone strength and composition in growing rats with and without corticosteroid treatment. However, human usage is restricted to antiresorption due to the poor therapeutic ratio (hypercalciuria and hypercalcemia as well as nephrotoxicity).
• One aspect of the present invention provides a 3-desoxy vitamin D 3 analog ester of the formula:
• L is a linker selected from the group consisting of:
• each of R 2 and R 3 is independently alkyl or haloalkyl; or R 2 and R 3 and together with the carbon atom to which they are attached to form a cycloalkyl; and each of R 1 and R 4 is independently hydrogen, alkyl, acyl group or other hydroxy protecting group, provided at least one of R 1 and R 4 is an acyl group.
• Acyl refers to a moiety of the formula -C(O)R', where R' is alkyl, heteroalkyl, cycloalkyl, aryl, heteroaryl, aralkyl or heteroaralkyl.
• Alkyl means a linear fully- saturated hydrocarbon moiety having one to six, preferably one to four, carbon atoms or a branched fully saturated hydrocarbon moiety having three or six carbon atoms.
• Alkyl means a moiety of the formula -R a -R b , where R a is alkyl and R is aryl as defined herein.
• Aryl means a monocyclic or bicyclic aromatic hydrocarbon moiety.
• one or more, preferably one, two or three, hydrogen atoms of the aryl moiety can be replaced by halo, nitro, cyano, hydroxy, amino, alkyl or alkoxy.
• exemplary aryl groups include phenyl and naphthalenyl which can be substituted with one or more substituents listed above.
• aryl is phenyl.
• Cycloalkyl means a fully saturated cyclic hydrocarbon moiety of three to six ring carbon atoms, e.g., cyclopropyl, cyclopentyl and the like.
• Haloalkyl refers to an alkyl moiety, as defined above, in which one or more hydrogen atoms attached to the carbon backbone have been replaced with one or more halides. Preferred halide is fluoride.
• Heteroalkyl means an alkyl moiety as defined herein having one or more, preferably one, two or three, substituents selected from -NR a R , -OR c wherein R a , R b and R c are independently of each other hydrogen, alkyl, or the corresponding protecting group.
• Heteroaralkyl means a moiety of the formula -R a -R , where R a is alkyl and R is heteroaryl as defined herein.
• Heteroaryl means a monocyclic or bicyclic radical of 5 to 12 ring atoms having at least one aromatic ring containing one, two, or three ring heteroatoms selected from N, O, or S, the remaining ring atoms being C, with the understanding that the attachment point of the heteroaryl radical will be on an aromatic ring
• one or more, preferably one, two or three, hydrogen atoms of the heteroaryl moiety can be replaced by the substituents described above for the aryl group.
• hydroxy protecting group and "other hydroxy protecting group” are used interchangeably herein and refer to hydroxy protecting groups known to one skilled in the art excluding alkyl or acyl groups, which are referred herein specifically.
• Representative hydroxy protecting groups include silyl ethers, carbonates, carbamates, substituted methyl ethers, substituted ethyl ethers, and the like.
• a list of other suitable hydroxy protecting groups can be found, for example, in Protective Groups in Organic Synthesis, 3rd edition, T.W. Greene and P.G.M. Wuts, John Wiley & Sons, New York, 1999, which is incorporated herein by reference in its entirety.
• “Pharmaceutically acceptable excipient” means an excipient that is useful in preparing a pharmaceutical composition that is generally safe, non-toxic and neither biologically nor otherwise undesirable, and includes an excipient that is acceptable for veterinary use as well as human pharmaceutical use. "A pharmaceutically acceptable excipient” as used in the specification and claims includes both one and more than one such excipient.
• “Therapeutically effective amount” means the amount of a compound that, when administered to a mammal for treating or preventing a disease, is sufficient to effect such treatment or prevention for the disease.
• the “therapeutically effective amount” will vary depending on the compound, the disease and its severity and the age, weight, etc., of the patient to be treated.
• Treating" or “treatment” of a disease includes: (1) preventing the disease, i.e. causing the clinical symptoms of the disease not to develop in a mammal that may be exposed to or predisposed to the disease but does not yet experience or display symptoms of the disease, (2) inhibiting the disease, i.e., arresting or reducing the development of the disease or its clinical symptoms, or (3) relieving the disease, i.e., causing regression of the disease or its clinical symptoms.
• the terms “treating”, “contacting” and “reacting” are used interchangeably herein and refer to adding or mixing two or more reagents under appropriate conditions to produce the indicated and/or the desired product. It should be appreciated that the reaction which produces the indicated and/or the desired product may not necessarily result directly from the combination of two reagents which were initially added, i.e., there maybe one or more intermediates which are produced in the mixture which ultimately leads to the formation of the indicated and/or the desired product.
• Haloalkyl refers to an alkyl radical, as defined above, in which one or more hydrogen atoms attached to the carbon backbone have been replaced with one or more halides. Preferred halide is fluoride.
• Pro-drugs means any compound which releases an active parent drug according to Formula (I) in vivo when such prodrug is administered to a mammalian subject. Prodrugs of a compound of Formula (I) are prepared by modifying functional groups present in the compound of Formula (I) in such a way that the modifications may be cleaved in vivo to release the parent compound.
• Prodrugs include compounds of Formula (I) wherein a hydroxy group in compound (I) is bonded to any group that may be cleaved in vivo to regenerate the free hydroxyl group.
• Examples of prodrugs include, but are not limited to esters (e.g., acetate, formate, and benzoate derivatives), carbamates (e.g., N,N-dimethylaminocarbonyl) and ethers of hydroxy functional groups in compounds of Formula (I), and the like. Such compounds are routinely made by one of skill in the art by acylating or etherifying the hydroxy group in the parent molecule.
• “Hydroxy protecting group” refers to a grouping of atoms that when attached to a hydroxy group in a molecule masks, reduces or prevents the reactivity of the hydroxy group. Examples of protecting groups can be found in T.W. Green and P.G. Futs, Protective Groups in Organic Chemistry, (Wiley, 2 n ed. 1999) and Harrison and Harrison et al., Compendium of Synthetic Organic Methods, Vols. 1-8 (John Wiley and Sons, 1971- 1996).
• hydroxy protecting groups include those where the hydroxy group is either acylated or alkylated such as benzyl, and trityl ethers as well as alkyl ethers, tetrahydropyranyl ethers, trialkylsilyl ethers and allyl ethers.
• one aspect of the present invention provides a method for treating osteoporosis or hyperparathyroidism comprising administering a 3- desoxy-l ⁇ -hydroxy vitamin D 3 analog to the patient, wherein said 3-desoxy vitamin D 3 analog is of the formula:
• L is a linker selected from the group consisting of:
• each of R and R is selected from the group consisting of hydrogen and alkyl; and each of R 2 and R 3 is independently selected from the group consisting of alkyl and haloalkyl, or R 2 and R 3 and together with the carbon atom to which they are attached to form a cycloalkyl.
• Another aspect of the present invention provides a method for producing a compound of the formula:
• each of R 1 and R 4 is selected from the group consisting of hydrogen, alkyl, and a hydroxy protecting group; and each of R and R is independently selected from the group consisting of alkyl; haloalkyl; or R 2 and R 3 and together with the carbon atom to which they are attached to form a cycloalkyl.
• the method further comprises the steps of protecting the hydroxy group of said ketone of Formula II prior to said step of contacting with said phosphine oxide compound of Formula III and removing the hydroxy protecting group after contacting said ketone of Formula II with said phosphine oxide compound of Formula III to produce said compound of Formula I.
• dotted line is optionally a double bond
• L is a linker selected from the group consisting of:
• each of R 2 and R 3 is independently alkyl or haloalkyl; or R 2 and R 3 and together with the carbon atom to which they are attached to form a cycloalkyl; and
• each of R and R is independently hydrogen, alkyl, acyl group or other hydroxy protecting group
• R 1 and R 4 are acyl groups.
• R 1 , R 2 , R 3 , R 4 and L are those defined in Claim 1.
• Another preferred aspect of the invention is a compound of the formula
• L is selected from the group consisting of:
• Another preferred aspect of the invention is a compound according to formula I, wherein R is an acyl group.
• each of R 2 and R 3 is independently selected from the group consisting of alkyl and haloalkyl .
• Another preferred aspect of the invention are compounds of formula I, wherein R 2 and R 3 are trifluoromethyl.
• each of Ar 1 and Ar 2 is independently optionally substituted aryl
• dotted line is optionally a double bond
• L is a linker selected from the group consisting of:
• each of R 2 and R 3 is independently alkyl or haloalkyl; or R 2 and R 3 and together with the carbon atom to which they are attached to form a cycloalkyl; and
• each of R and R is independently alkyl, an acyl group or a hydroxy protecting group
• R 1 and R 4 are hydroxy protecting groups.
• R la is an acyl group and R 4a is hydrogen or an acyl group.
• R a is an acyl group.
• Ar 1 and Ar 2 are phenyl.
• Another preferred aspect of the invention is a compound according to formula I, when manufactured according to the above method.
• composition comprising a compound according to formula I and a pharmaceutically acceptable excipient.
• Another preferred aspect of the present invention are compounds according to formula I for the preparation of medicaments for the prophylaxis and therapy of bone related diseases.
• a method according to formula I wherein the disease is selected from hyperparathyroidism, secondary hyperparathyroidism, renal osteodystrophy and osteoporosis.
• Another preferred aspect of the invention is a method for treating a bone-related disease in a patient comprising administering to the patient a compound according to formula
• dotted line is optionally a double bond
• L is a linker selected from the group consisting of:
• each of R 1 and R 4 is selected from the group consisting of hydrogen or alkyl
• each of R and R 3 is independently selected from the group consisting of alkyl or haloalkyl, or R 2 and R 3 and together with the carbon atom to which they are attached to form a cycloalkyl.
• Particularly preferred is the above method for treating a bone-related disease in a patient, comprising administering to the patient a compound according to formula I.
• dotted line is optionally a double bond
• L is a linker selected from the group consisting of:
• each of R and R is selected from the group consisting of hydrogen or alkyl
• each of R and R 3 is independently selected from the group consisting of alkyl or haloalkyl, or R and R and together with the carbon atom to which they are attached to form a cycloalkyl.
• the bone related disease is hyperparathyroidism, renal osteodystrophy or osteoporosis.
• R 1 , R 2 , R 3 , R 4 and L are defined as before.
• linker L is selected from the group consisting of:
• linker L is selected from the group consisting of:
• each of R 2 and R is independently selected from the group consisting of alkyl and haloalkyl.
• the above method or use wherein the disease is osteoporosis. Additionally, preferred is the above method or use, wherein the disease is healing or reducing the incidence of a fracture.
• each of Ar 1 and Ar 2 is independently optionally substituted aryl
• dotted line is optionally a double bond
• L is a linker selected from the group consisting of:
• each of R and R is selected from the group consisting of hydrogen and alkyl
• each of R and R is independently selected from the group consisting of alkyl and haloalkyl, or R and R 3 and together with the carbon atom to which they are attached form a cycloalkyl.
• the above method for producing further comprising the steps of protecting the hydroxy group of said ketone of Formula II prior to said step of contacting with said phosphine oxide compound of Formula III and removing the hydroxy protecting group after contacting said ketone of Formula II with said phosphine oxide compound of Formula III to produce said compound of Formula I.
• One aspect of the present invention provides a 3-desoxy-20-desmethyl-20- cyclopropyl vitamin D 3 analog ester of the formula:
• each of R 2 and R 3 is independently alkyl or haloalkyl; or R 2 and R 3 and together with the carbon atom to which they are attached to form a cycloalkyl; and each of R and R is independently hydrogen, alkyl, acyl group or other hydroxy protecting group, provided at least one of R 1 and R 4 is an acyl group.
• the stereochemistry of the side chain on the cyclopentane ring system can be alpha or beta.
• the stereochemistry of the side chain on the cyclopentane ring system is beta, i.e., of the formula:
• the 3-desoxy vitamin D 3 analog ester is of the formula:
• R 1 , R 2 , R 3 , R 4 and L are those defined herein.
• R 1 is preferably an acyl group, more preferably acetyl.
• R 1 is an acyl group and R is hydrogen or an acyl group.
• R 1 is an acyl group and each of R 2 and R 3 is independently selected from the group consisting of methyl, ethyl and trifluoromethyl.
• R 2 and R 3 are alkyl or haloalkyl, preferably methyl or trifluoromethyl, most preferably trifluoromethyl.
• substituent preferences have been given above and following any of these substituent preferences results in a compound of the invention that is more preferred than one in which the particular substituent preference is not followed.
• substituent preferences are generally independent, although some preferences are mutually exclusive, and following more than one of these preferences may result in a more preferred compound than one in which fewer of the substituent preferences are followed.
• the present invention is directed to a method for treating osteoporosis, hyperparathyroidism or an autoimmune disease in a patient by administering a 3-desoxy vitamin D 3 analog of Formula I, where R 1 , R 2 , R 3 , R 4 and L are as defined in the Summary of the Invention.
• the stereochemistry of the side chain on the cyclopentane ring system can be alpha or beta.
• the stereochemistry of the side chain on the cyclopentane ring system is beta, i.e., of the formula:
• the 3-desoxy vitamin D 3 analog is the formula:
• R 1 , R 2 , R 3 , R 4 and L are as defined in the Summary of the Invention.
• R 1 is hydrogen.
• R 4 is hydrogen. In another embodiment, both R and R 4 are hydrogen.
• each of R 2 and R 3 is independently alkyl or haloalkyl, preferably methyl or trifluoromethyl.
• substituent preferences have been given above and following any of these substituent preferences results in a compound of the invention that is more preferred than one in which the particular substituent preference is not followed.
• substituent preferences are generally independent, although some preferences are mutually exclusive, and following more than one of these preferences may result in a more preferred compound than one in which fewer of the substituent preferences are followed.
• each of R and R is independently alkyl or haloalkyl; or R" and R and together with the carbon atom to which they are attached to form a cycloalkyl; and each of R 1 and R is independently alkyl, an acyl group or a hydroxy protecting group, and
• acylating step (b) when neither R 1 nor R is an acyl group, acylating the compound of Formula I with an acylating agent under conditions sufficient to produce a Compound of Formula I where at least one of R and R is an acyl group.
• R 1 and R 4 are hydroxy protecting groups.
• the acylating step (b) comprises:
• step (i) removing the hydroxy groups by contacting the resulting compound of said step (a) with a hydroxy protecting group removing compound under conditions sufficient to produce a l-hydroxy-3-desoxy vitamin D 3 analog of the formula:
• R la is an acyl group and R 4a is hydrogen or an acyl group.
• R a is an acyl group.
• Ar 1 and Ar 2 are phenyl.
• hydroxy protecting groups are well known to one of ordinary skill in the art and examples of such hydroxy protecting groups are disclosed in Protective Groups in Organic Synthesis, 3rd edition, T.W. Greene and P.G.M. Wuts, John Wiley & Sons, New York, 1999, and Harrison and Harrison et al, Compendium of Synthetic Organic Methods, Vols. 1-8 (John Wiley and Sons, 1971-1996), which are incorporated herein by reference in their entirety.
• Representative hydroxy protecting groups include benzyl and trityl ethers, tetrahydropyranyl ethers, trialkylsilyl ethers, carbamates and allyl ethers.
• hydroxy groups are protected as silyl ethers; however, the scope of the invention includes the use of alternative hydroxyl protecting groups known in the art as described in the above disclosed Protective Groups in Organic Synthesis, 3rd edition, and Compendium of Synthetic Organic Methods, Vols. 1-8.
• a phosphine oxide of Formula III in tetrahydrofuran is reacted with n- butyllithium typically at about -78 °C.
• n- butyllithium typically at about -78 °C.
• a ketone of Formula II in tetrahydrofuran to provide a compound of Formula I.
• R 1 and/or R are hydrogen, they are protected with hydroxy protecting groups prior to the coupling reaction.
• Reaction Scheme 1 illustrates a synthetic method for preparing a compound of Formula IA.
• the compound of Formula IV is a known compound prepared by the method described in WO99/12894, published March 18, 1999 (Preparation of 1,3- dihydroxy-20,20-dialkyl vitamin D3 analogs).
• the compound of Formula IV is converted to the compound of Formula V by selective partial reduction of the triple bond to anb E- double bond using lithium aluminum hydride in inert organic acid such as tetrahydrofuran.
• the reaction is typically conducted by adding the compound of Formula IV to a suspension of LiAlH in THF at 0 °C or 5 °C.
• the reaction mixture is heated under refluxing condition to provide the compound of Formula V.
• the compound of Formula V is converted to the ketone of Formula VI by oxidation using an oxidizing agent such as pyridinium dichromate.
• the reaction is generally conducted in a halogenated solvent such as methylene chloride at room temperature.
• a halogenated solvent such as methylene chloride at room temperature.
• the hydroxy group of compound of Formula VI is then protected as a silyl ether of Formula VII using a silylating agent, such as 1- (trimethylsilyl)imidazole, trimethylsilyl chloride or trimethylsilyl triflate, in an inert solvent, such as a halogenated solvent (e.g., methylene chloride), at room temperature.
• a halogenated solvent e.g., methylene chloride
• the compound of Formula IIIA is reacted with n-butyllithium and the resulting compound is reacted with the compound of Formula VII in tetrahydrofuran at temperature of generally about -78 ° C, and the silyl protecting groups are then removed, for example, with tetrabutylammonium fluoride in tetrahydrofuran solvent to give the compound of Formula IA'.
• the free hydroxyl groups are then acetylated to provide the compound of Formula I A, for example, with acetic anhydride in pyridine.
• the secondary hydroxyl group is generally more reactive, it can be selectively acetylated depending on the amount of acetylating agent used and/or the reaction conditions used, e.g., the reaction temperature and/or the reaction time.
• both the secondary and the tertiary hydroxyl groups can be acteylated by using an excess amount of the acetylating agent and longer reaction time.
• a Z-stereoisomer analog or a saturated carbon chain analog of compound of Formula IA can be prepared by reduction of the compound of Formula IV with hydrogen in the presence of an appropriate hydrogenation catalyst, such as Pd-S or Pd, respectively.
• an appropriate hydrogenation catalyst such as Pd-S or Pd, respectively.
• the resulting compounds can be subjected to similar reaction conditions as shown in Scheme I to produce the corresponding a Z-isomer analog and a saturated carbon chain analog of the compound of Formula IA.
• a compound of Formula II comprising an acetylenic alcohol and varying alkyl, haloalkyl and cycloalkyl groups of R 2 and R 3 can be prepared by condensing an acetylide anion derived from a compound of Formula VIII (where Pg is a hydroxy protecting group) with an appropriate ketone, haloketone (e.g. hexafluoroacetone) and cycloketone, and removing the protecting group.
• Pg is a hydroxy protecting group
• Scheme II The compound of Formula X is then subjected to a similar reaction conditions shown above in Reaction Scheme I (i.e., oxidation, protection and coupling) to produce a compound of Formula I having an acetylenic linker moiety.
• the dotted line is a double bond, i.e., a compound of the formula:
• the linker L is selected from the group consisting of:
• R 1 is an acyl group.
• R is hydrogen or an acyl group.
• each of R 2 and R 3 is independently selected from the group consisting of methyl, ethyl and trifluoromethyl or R 2 and R 3 together with the carbon atom to which they are attached to form a cyclopentyl ring.
• substituent preferences have been given above and following any of these substituent preferences results in a compound of the invention that is more preferred than one in which the particular substituent preference is not followed.
• substituent preferences are generally independent, although some preferences are mutually exclusive, and following more than one of these preferences may result in a more preferred compound than one in which fewer of the substituent preferences are followed.
• Another aspect of the invention provides salts of a compound of Formula I.
• each of Ar 1 and Ar 2 is independently optionally substituted aryl, and the dotted line, R 1 , R 2 , R 3 , R 4 and L are as defined in the Summary of the Invention.
• Ar 1 and Ar 2 are phenyl.
• R 1 and/or R 4 are hydrogen, the corresponding hydroxy groups are preferably protected with hydroxy protecting groups that are compatible with the coupling reaction conditions prior to the coupling reaction between the ketone of Formula II and the phosphine oxide compound of Formula III.
• Suitable hydroxy protecting groups are well known to one of ordinary skill in the art and examples of such hydroxy protecting groups are disclosed in Protective Groups in Organic Synthesis, 3rd edition, T.W. Greene and P.G.M.
• hydroxy protecting groups include benzyl and trityl ethers, tetrahydropyranyl ethers, trialkylsilyl ethers and allyl ethers.
• hydroxy groups are protected as silylethers; however, the scope of the invention includes the use of alternative hydroxyl protecting groups known in the art as described in the above disclosed Protective Groups in Organic Synthesis, 3rd edition, and Compendium of Synthetic Organic Methods, Vols. 1-8.
• a phosphine oxide compound of Formula III in tetrahydrofuran is reacted with n-butyllithium typically at about -78 °C.
• n-butyllithium typically at about -78 °C.
• a ketone of Formula II in tetrahydrofuran is then added to provide a compound of Formula I.
• R 1 and/or R 4 are hydrogen, they are protected with hydroxy protecting groups prior to the coupling reaction. In such a case, the hydroxy protecting groups are then removed to provide a compound of Formula I.
• Reaction Scheme la illustrates a synthetic method for preparing a compound of Formula IA.
• the compound of Formula IV is a known compound prepared by the method described in WO99/12894, published March 18, 1999 (Preparation of l,3-dihydroxy-20,20-dialkyl vitamin D3 analogs).
• the compound of Formula IV is converted to the compound of Formula V by selective partial reduction of the triple bond to an E-double bond using lithium aluminum hydride in inert organic acid such as tetrahydrofuran.
• the reaction is typically conducted by adding the compound of Formula IV to a suspension of LiAlH in THF at 0 °C or 5 °C. The reaction mixture is heated under refluxing condition to provide the compound of Formula V.
• the compound of Formula V is converted to the ketone compound of Formula VI by oxidation using an oxidizing agent such as pyridinium dichromate.
• the reaction is generally conducted in a halogenated solvent such as methylene chloride at room temperature.
• a halogenated solvent such as methylene chloride at room temperature.
• the hydroxy group of compound of Formula VI is then protected as a silyl ether of Formula VII using a silylating agent, such as l-(trimethylsilyl)imidazole, trimethylsilyl chloride or trimethylsilyl triflate, in an inert solvent, such as a halogenated solvent (e.g., methylene chloride), at room temperature.
• a silylating agent such as l-(trimethylsilyl)imidazole, trimethylsilyl chloride or trimethylsilyl triflate
• the compound of Formula Ilia is reacted with n-butyllithium and the resulting compound is reacted with the compound of Formula VII in tetrahydrofuran at a temperature of -78° C to give the compound of Formula IA after removal of silyl protecting groups, for example, with tetrabutylammonium fluoride in tetrahydrofuran solvent.
• a Z-stereoisomer analog or a saturated carbon chain analog of compound of Formula IA can be prepared by reduction of the compound of Formula IV with hydrogen in the presence of an appropriate hydrogenation catalyst, such as Pd-S or Pd, respectively.
• an appropriate hydrogenation catalyst such as Pd-S or Pd, respectively.
• the resulting compounds can be subjected to similar reaction conditions as shown in Scheme la to produce the corresponding a Z-isomer analog and a saturated carbon chain analog of the compound of Formula IA.
• a compound of Formula II comprising an acetylenic alcohol and varying alkyl, haloalkyl and cycloalkyl groups of R 2 and R can be prepared by condensing an acetylide anion derived from a compound of Formula VIII (where Pg is a hydroxy protecting group) with an appropriate ketone, haloketone (e.g. hexafluoroacetone) and cycloketone, and removing the protecting group.
• Pg is a hydroxy protecting group
• the compounds of the present invention are useful for the prevention and treatment of a variety of mammalian conditions manifested by loss of bone mass. All such conditions are referred to as "bone-related diseases" and are described in more detail hereunder.
• the compounds of this invention are indicated for the prophylaxis and therapeutic treatment of osteoporosis and osteopenia in mammals without inducing hypercalciuria, hypercalcemia, or nephrotoxicity.
• “Hypercalcemia” is an excessive concentration of calcium in the serum; in humans (and rats) this corresponds to greater than about 10.5 mg/dl.
• Withinlerable hypercalcemia usually occurring at serum calcium concentrations greater than about 12 mg/dl, is associated with emotional lability, confusion, delirium, psychosis, stupor, and coma.
• the compounds of the present invention are useful in the treatment of Type I (postmenopausal), Type II (iatrogenic), and Type III (senile) osteoporosis, including that associated with corticosteroid treatment (e.g. for asthma), as well in the treatment of osteodystrophy due to renal dialysis and hyperparathyroidism.
• Treatment with the vitamin D3 analogs as described herein results in increased bone mineral density and unlike conventional treatments provides bone of good quality. Therefore, the treatments described herein may reduce the incidence of fracture and result in faster healing of pre- existing fractures.
• Such treatments are particularly useful for patients suffering from estrogen withdrawal (e.g. elderly females) who would otherwise be at risk for an increased fracture rate.
• Types of fractures treatable include both traumatic and osteoporotic fractures, e.g., fractures of the hip, neck of the femur, wrist, vertebrae, spine, ribs, sternum, larynx and trachea, radius/ulna, tibia, patella, clavicle, pelvis, humerus, lower leg, fingers and toes, face and ankle.
• traumatic and osteoporotic fractures e.g., fractures of the hip, neck of the femur, wrist, vertebrae, spine, ribs, sternum, larynx and trachea, radius/ulna, tibia, patella, clavicle, pelvis, humerus, lower leg, fingers and toes, face and ankle.
• the compounds of the present invention are also useful in treating diseases caused by elevated levels of parathyroid hormone.
• compounds of the invention are used in treating secondary hyperparathyroidism associated with renal failure and in particular with reversing or reducing the bone loss associated with renal insufficiency.
• Other aspects include the treatment of renal osteodystrophy associated with late stage secondary hyperparathyroidism.
• Other aspects include the treatment of primary hyperparathyroidism.
• Compounds of Formula I are also useful in treating neoplastic diseases such as leukemia, colon cancer, breast cancer and prostate cancer.
• neoplastic diseases such as leukemia, colon cancer, breast cancer and prostate cancer.
• compounds of the present invention do not cause the elevated calcium levels observed with other vitamin D 3 analogs such as 1,25 (OH) 2 vitamin D 3 , thus providing an improved therapeutic ratio and better treatment of the above diseases.
• the compound of this invention may be administered in amounts between about 0.0002 and 0.5 mg compound/kg body weight per day, preferably from about 0.001 to about 0.1 mg/kg body weight per day, more preferably from about 0.002 to about 0.02 mg/kg body weight per day, most preferably from about 0.005 to about 0.010 mg/kg body weight per day.
• the daily dose of active ingredient may be from about 0.01 to about 25 ⁇ gs, preferably from about 0.05 to about 10 ⁇ gs, most preferably from about 1.0 ⁇ g to about 10 ⁇ g per day.
• This dosage can be delivered in a conventional pharmaceutical composition by a single administration, by multiple applications, or via controlled release, as needed to achieve the most effective results, preferably once or twice daily by mouth. In certain situations, alternate day dosing can prove adequate to achieve the desired therapeutic response.
• the selection of the exact dose and composition and the most appropriate delivery regimen are influenced by, inter alia, the pharmacological properties of the formulation, the nature and severity of the condition being treated, and the physical condition and mental acuity of the recipient. In general, the requisite dose is greater for higher doses of corticosteroids in the treatment of corticosteroid induced osteopenia.
• Representative delivery regimens include oral, parenteral (including subcutaneous, intramuscular and intravenous), rectal, buccal (including sublingual), pulmonary, transdermal, and intranasal, most preferably oral. Administration can be continuous or intermittent (e.g., by bolus injection).
• a related aspect of this invention relates to combination therapies of compounds of Formula I with other active agents such as bisphosphonates, estrogen, SERMS (selective estrogen receptor modulators), calcitonins or anabolic therapies.
• active agents such as bisphosphonates, estrogen, SERMS (selective estrogen receptor modulators), calcitonins or anabolic therapies.
• bisphosphonates include alendronate, ibandronate, pamidronate, etidronate and risedronate.
• SERMS include raloxifene, dihydroraloxifene and lasofoxifene.
• Calcitonins include human and salmon calcitonin.
• Anabolic agents include parathyroid hormones (PTH) e.g. hPTH(l-34), PTH(l-84), and parathyroid hormone-related protein (PTHrP) and analogs thereof.
• PTHrP Parathyroid Hormone-Related Protein. 1. Synthesis and Biological Studies," Michael Chorev et al. Biochemistry, 36:3293-3299 (1997) and "Cyclic analogs of PTH and PTHrP," WO 96/40193 and U.S. Patent No. 5,589,452 and WO 97/07815.
• the other active agent may be administered concurrently, prior to or after the compound of Formula I and may be administered by a different delivery method.
• compositions comprising a compound of the present invention as an active ingredient in admixture with a pharmaceutically acceptable non-toxic carrier.
• a pharmaceutically acceptable non-toxic carrier can be prepared for parenteral (subcutaneous, intramuscular or intravenous) administration, particularly in the form of liquid solutions or suspensions; for oral or buccal administration, particularly in the form of tablets or capsules; for pulmonary or intranasal administration, particularly in the form of powders, nasal drops or aerosols; and for rectal or transdermal administration.
• compositions of the present invention can conveniently be administered in unit dosage form and can be prepared by any of the methods well-known in the pharmaceutical art, for example, as described in Remington's Pharmaceutical Sciences, 17th ed., Mack Publishing Company, Easton, PA (1985).
• Formulations for parenteral administration can contain as excipients sterile water or saline, alkylene glycols such as propylene glycol, polyalkylene glycols such as polyethylene glycol, oils of vegetable origin, hydrogenated naphthalenes and the like.
• Formulations for nasal administration can be solid and can contain excipients, for example, lactose or dextran, or can be aqueous or oily solutions for use in the form of nasal drops or metered spray.
• typical excipients include sugars, calcium stearate, magnesium stearate, pregelatinated starch, and the like.
• Orally administrable compositions can comprise one or more physiologically compatible carriers and/or excipients and can be in solid or liquid form.
• Tablets and capsules can be prepared with binding agents, for example, syrup, acacia, gelatin, sorbitol, tragacanth, or poly-vinylpyrollidone; fillers, such as lactose, sucrose, corn starch, calcium phosphate, sorbitol, or glycine; lubricants, such as magnesium stearate, talc, polyethylene glycol, or silica; and surfactants, such as sodium lauryl sulfate.
• binding agents for example, syrup, acacia, gelatin, sorbitol, tragacanth, or poly-vinylpyrollidone
• fillers such as lactose, sucrose, corn starch, calcium phosphate, sorbitol, or glycine
• lubricants such as magnesium stearate, talc, polyethylene glyco
• Liquid compositions can contain conventional additives such as suspending agents, for example sorbitol syrup, methyl cellulose, sugar syrup, gelatin, carboxymethylcellulose, or edible fats; emulsifying agents such as lecithin, or acacia; vegetable oils such as almond oil, coconut oil, cod liver oil, or peanut oil; preservatives such as butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT).
• suspending agents for example sorbitol syrup, methyl cellulose, sugar syrup, gelatin, carboxymethylcellulose, or edible fats
• emulsifying agents such as lecithin, or acacia
• vegetable oils such as almond oil, coconut oil, cod liver oil, or peanut oil
• preservatives such as butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT).
• Liquid compositions can be encapsulated in, for example, gelatin to provide a unit dosage form.
• Preferred solid oral dosage forms include tablets, two-piece hard shell capsules and soft elastic gelatin (SEG) capsules.
• SEG capsules are of particular interest because they provide distinct advantages over the other two forms (see Seager, H., "Soft gelatin capsules: a solution to many tableting problems"; Pharmaceutical Technology, 9, (1985).
• SEG capsules Some of the advantages of using SEG capsules are: a) dose- content uniformity is optimized in SEG capsules because the drug is dissolved or dispersed in a liquid that can be dosed into the capsules accurately, b) drugs formulated as SEG capsules show good bioavailability because the drug is dissolved, solubilized or dispersed in an aqueous-miscible or oily liquid and therefore when released in the body the solutions dissolve or are emulsified to produce drug dispersions of high surface area, and c) degradation of drugs that are sensitive to oxidation during long-term storage is prevented because the dry shell of soft gelatin provides a barrier against the diffusion of oxygen.
• the dry shell formulation typically comprises of about 40% to 60% concentration of gelatin, about a 20% to 30% concentration of plasticizer (such as glycerin, sorbitol or propylene glycol) and about a 30 to 40% concentration of water. Other materials such as preservatives, dyes, opacifiers and flavours also can be present.
• the liquid fill material comprises a solid drug that has been dissolved, solubilized or dispersed (with suspending agents such as beeswax, hydrogenated castor oil or polyethylene glycol 4000) or a liquid drug in vehicles or combinations of vehicles such as mineral oil, vegetable oils, triglycerides, glycols, polyols and surface-active agents.
• This example illustrate a method for producing [lR-(l ⁇ (E),3a ⁇ ,7a ⁇ )]-Octahydro- 7a-methyl-l-[5,5,5-trifluoro-4-hydroxy-4-(trifluoromethyl)-2-pentynyl]cyclopropyl]-4H- inden-4-ol.
• Example 2 This example illustrate a method for producing [lR-(l (E),3a ⁇ ,7a ⁇ )] ]Octahydro- 7a-methyl-l- [ 1- [ 1- [5,5,5-trifluoro-4-hydroxy-4-(trifluoromethyl)-2- pentynyl] cyclopropyl] -4H-inden-4-one.
• This example illustrates a method for producing [lR-[l ⁇ (E),3a ⁇ ,7a ⁇ )] ]-Octahydro- 7a-methyl- 1- [ 1- [5,5,5-trifluoro-4- trifluoromethyl) -4- [ (trimethylsilyl) oxy] -2- pentynyl] cyclopropyl] -4H-inden-4-one.
• Example 4 This example illustrates a method for producing 3-desoxy-l,25-dihydroxy-20- methyl-23-(E)-ene-26,27-hexafluoro-21,28-cyclochole-calciferol.
• Example 6 This example illustrates a method for producing 3-desoxy- l,25-dihydroxy-20- methyl-23-yne-21,28-cyclocholecalciferol.
• Example 7 This example illustrates a method for producing 3-desoxy- l,25-dihydroxy-20- methyl-23-yne-26,27-hexafluoro-21,28-cyclocholecalciferol.
• Example 8 This example illustrates a method for producing 3-desoxy- l,25-dihydroxy-20- methyl-21,28-cyclocholecalciferol.
• the aqueous layer was re- extracted with 20 ml of ethyl acetate. Both organic layers were combined and washed with 5 x 35 ml water and once with brine, then passed through a plug of sodium sulfate and evaporated to a crystalline, white residue, 0.3523 gr.
• This material was chromatographed on a 25 x 110 mm column using 1:1 ethyl acetate-hexane as mobile phase. Fractions 3-4, already crystallizing in the tubes. The suspension so obtained was concentrated to a volume of ca 5 ml, diluted with hexane and concentrated, and filtered to give crystalline title compound 0.2567 gr.
• This example illustrate a method for synthesizing 3-desoxy- l ⁇ - acetoxy-25-hydroxy- 20-cyclopropyl-23E-ene-26,27-hexafluoro-cholecalciferol.
• a 25-mL round bottom flask was charged with 0.1702 g of 3-desoxy- l ,25- dihydroxy-20-cyclopropyl-23E-ene-26,27-hexafluoro-cholecalciferol and 2.85 g of pyridine.
• the solution was stirred and cooled in an ice bath, then 0.5 mL of acetic anhydride was added and stirring in the ice bath continued for one hour. At that time the solution was placed in the refrigerator overnight.
• the flask was returned to the ice-bath and 0.2 mL of acetic anhydride was added.
• UV max, nm (absorbance) 121 (0.3639), 250 (0.4591), 262 (4486), 244 sh (0.4482).
• This example illustrate a method for synthesizing 3-desoxy- l ,25-diacetoxy-20- cyclopropyl-23E-ene-26,27-hexafluoro-cholecalciferol.
• the pyridine was added while the flask was immersed in an ice bath. After 10 min, 1.0 mL of acetic anhydride was added dropwise and stirring in the ice bath continued. After 1 hour starting material was virtually undetectable.
• fractions 4-6 were combined and the residue re- chromatographed on a 15 x 150 mm column using 1:9 ethyl acetate - hexane as mobile phase and taking 20 mL fractions.
• Fractions 2 and 3 contained the bulk of the product in pure form. These fractions were added to fraction 3 of the first chromatogram, then evaporated. The residue was taken up in 1:9, filtered and concentrated, diluted with pentane and refrigerated. The mother liquor was withdrawn and the crystals rinsed with pentane, then dried at hivac for 2 h, to give 0.190 g of the title compound.
• MA 192020 found C, 63.99; H, 6.62; calcd C, 63.78; H, 6.69,
• UV max (Absorbance) 212 (0.3573), 251 (0.4392), 261 (0.4276).
• Example 11 This example illustrates a method of determining effectiveness of the compounds of the present invention for bone anabolism in the rat.
• Rats Three month old rats are ovariectomized (Ovx) and administered either 1,25- dihydroxy vitamin D 3 or one of the compounds of the present invention once a day by mouth starting at 3 weeks post-ovariectomy and continuing until final sacrifice at 6 weeks post-ovariectomy.
• Control groups both sham (rats that were not ovariectomized) and Ovx, receive vehicle only. Blood and urine samples are collected twice, at 4 weeks post- ovariectomy and again at the 6 week mark and the amount of serum and urine calcium is determined. The final femoral calcium is determined upon sacrifice 6 weeks post- ovariectomy.
• the bone mineral density of the right femur is determined by using a High Resolution Software Package on a QDR-1000W Bone Densitometer (Hologic, Walthan, MA).
• the animals are scanned by placing them on a scanning block in a supine position such that the right leg was perpendicular to the main body and the tibia was perpendicular to the femur.
• Example 12 This example illustrates a method for determining comparative in vivo efficacy of Compounds of the present invention and l,25-(OH) 2 Vitamin D 3 .
• Comparison of the efficacy of compounds of the present invention to that of 1,25- dihydroxy vitamin D 3 can be made using the standard animal model for post menopausal osteopenia, the rat ovariectomy model. Three month old rats were ovariectomized, and then treated for 8 weeks beginning 1 week post OVX. Drugs were administered once/day orally in miglyol (medium chain triglyceride) vehicle.
• Bone mineral density was determined in vivo at 6wk using Dual Energy X-ray Absorptiometry (Hologic QDR-4500TM Bone Scanner).
• Hologic QDR-4500TM Bone Scanner Dual Energy X-ray Absorptiometry
• the animals were sacrificed, and the lumbar vertebrae and femur bones removed for ex vivo BMD determination (Lunar PixiMusTM Bone Scanner) and biomechanical testing for strength. Data for each compound are then determined for the highest safe doses.
• the highest safe dose is defined as that which does not produce hypercalcemia as defined by serum calcium levels greater than 10.0 mg/dl.
• This example illustrates comparative in vivo efficacy of Compound 27 and 1,25- (OH) 2 Vitamin D 3 .
• the highest safe dose is defined as that which does not produce hypercalcemia as defined by serum calcium levels greater than 10.0 mg/dl.
• Table 3 shows the safety (serum calcium, urinary calcium) results.
• the doses being compared all gave 3wk serum calcium levels of 9.3mg/dl, and 6wk levels of 9.8 + O.lmg/dl.
• the urinary calcium output per 24hr sample was the same for the 0.4nmol/kg dose of VD 3 and the 0.5nmol/kg dose of Compound 27.
• Table 4 shows the efficacy parameters for the 2 compounds (BMD, biomechanics, and urinary deoxypyridinolines). BMD at all of the bone sites listed is significantly higher in the animals dosed with Compound 27 than those dosed with VD 3 at doses which give equivalent serum calcium levels.
• Urinary deoxy-pyridinolines a marker of bone resorption were significantly less for Compound 27 than VD 3 at 6 weeks showing greater ability of Compound 27 to inhibit bone resorption.
• Compound 27 treatment resulted in stronger vertebral bone.
• Failure Load the amount of force needed to fracture the L5 vertebra, was determined in axial compression testing. Significantly more force was needed to fracture the vertebrae of animals treated with Compound 27 compared to those treated with VD 3 at the highest safe doses.
• the compounds of the invention possess biological activity comparable to that of compound 27.

Landscapes

• Health & Medical Sciences (AREA)
• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Life Sciences & Earth Sciences (AREA)
• General Health & Medical Sciences (AREA)
• Physical Education & Sports Medicine (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Medicinal Chemistry (AREA)
• Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
• Bioinformatics & Cheminformatics (AREA)
• Pharmacology & Pharmacy (AREA)
• Engineering & Computer Science (AREA)
• Animal Behavior & Ethology (AREA)
• Veterinary Medicine (AREA)
• Public Health (AREA)
• Rheumatology (AREA)
• Orthopedic Medicine & Surgery (AREA)
• Diabetes (AREA)
• Endocrinology (AREA)
• Hematology (AREA)
• Obesity (AREA)
• Nutrition Science (AREA)
• Pharmaceuticals Containing Other Organic And Inorganic Compounds (AREA)
• Acyclic And Carbocyclic Compounds In Medicinal Compositions (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

Priority Applications (7)

Applications Claiming Priority (4)

Publications (1)

Family

ID=26984180

Family Applications (1)

Country Status (14)

Cited By (2)

Families Citing this family (3)

Citations (3)

• 2002
  • 2002-09-12 CA CA002459789A patent/CA2459789A1/en not_active Abandoned
  • 2002-09-12 CN CNB028185285A patent/CN1285573C/zh not_active Expired - Fee Related
  • 2002-09-12 MX MXPA04002640A patent/MXPA04002640A/es active IP Right Grant
  • 2002-09-12 RU RU2004112217/04A patent/RU2296121C2/ru not_active IP Right Cessation
  • 2002-09-12 PL PL02370352A patent/PL370352A1/xx not_active Application Discontinuation
  • 2002-09-12 WO PCT/EP2002/010233 patent/WO2003027065A1/en not_active Application Discontinuation
  • 2002-09-12 AU AU2002338672A patent/AU2002338672B2/en not_active Ceased
  • 2002-09-12 KR KR1020047004110A patent/KR100628586B1/ko not_active IP Right Cessation
  • 2002-09-12 JP JP2003530656A patent/JP2005503434A/ja active Pending
  • 2002-09-12 BR BR0212719-9A patent/BR0212719A/pt not_active IP Right Cessation
  • 2002-09-12 EP EP02777075A patent/EP1430026A1/en not_active Withdrawn
  • 2002-09-18 PA PA20028554901A patent/PA8554901A1/es unknown
  • 2002-09-19 PE PE2002000921A patent/PE20030429A1/es not_active Application Discontinuation
  • 2002-09-20 UY UY27448A patent/UY27448A1/es not_active Application Discontinuation

Patent Citations (3)

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events