(12) United States Patent
`US 7,326,708 B2
`(45) Date of Patent:
`Feb. 5, 2008
`Cypes et a1.
`
`(10) Patent No.:
`
`US007326708B2
`
`PHOSPHORIC ACID SALT OF A
`DIPEPTIDYL PEPTIDASE-IV INHIBITOR
`
`(56)
`
`References Cited
`U.S. PATENT DOCUMENTS
`
`........... 558/413
`11/2002 Ekwuribe et a1.
`6,479,692 B1 *
`3/2004 Edmondson et a1.
`6,699,871 B2
`5/2003 Edmondson et a1.
`2003/0100563 A1
`2006/0287528 A1* 12/2006 Wenslow et a1.
`........... 544/350
`2007/0021430 A1*
`1/2007 Chen et a1.
`................. 514/249
`
`FOREIGN PATENT DOCUMENTS
`
`W0
`W0
`
`WO 2005/072530 A1
`WO 2006/033848 A1
`
`8/2005
`3/2006
`
`OTHER PUBLICATIONS
`
`Edmondson, S.D., Drug Data Report, v01. 25, N0. 3, pp. 245-246
`(2003).
`Database Prous DDR OnlineiDatabase Accession No. 2003: 3561.
`
`* cited by examiner
`
`Primary Examinerilames O. Wilson
`Assistant ExamineriEbenezer Sackey
`(74) Attorney, Agent, or FirmiPhilippe L. Durette;
`Catherine D. Fitch
`
`(57)
`
`ABSTRACT
`
`The dihydrogenphosphate salt of 4-oxo-4-[3-(trifluorom-
`ethyl)-5,6-dihydro [1 ,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl] -
`1-(2,4,5-trifluorophenyl)butan-2-amine is a potent inhibitor
`of dipeptidyl peptidase-IV and is useful for the prevention
`and/or treatment of non-insulin dependent diabetes mellitus,
`also referred to as type 2 diabetes. The invention also relates
`to a crystalline monohydrate of the dihydrogenphosphate
`salt as well as a process for its preparation, pharmaceutical
`compositions containing this novel form and methods of use
`for the treatment of diabetes, obesity, and high blood pres-
`sure.
`
`(54)
`
`(75)
`
`Inventors: Stephen Howard Cypes, Santa Clara,
`CA (US); Alex Minhua Chen,
`Metuchen, NJ (US); Russell R. Ferlita,
`Westfield, NJ (US); Karl Hansen,
`Atlantic Highlands, NJ (US); Ivan Lee,
`Piscataway, NJ (US); Vicky K. Vydra,
`Fair Lawn, NJ (US); Robert M.
`Wenslow, Jr., East Windsor, NJ (US)
`
`(73)
`
`Assignee: Merck & Co., Inc., Rahway, NJ (US)
`
`(*)
`
`Notice:
`
`Subject to any disclaimer, the term of this
`patent is extended or adjusted under 35
`U.S.C. 154(b) by 657 days.
`
`(21)
`
`Appl. No.: 10/874,992
`
`(22)
`
`Filed:
`
`Jun. 23, 2004
`
`(65)
`
`Prior Publication Data
`
`US 2005/0032804 A1
`
`Feb. 10, 2005
`
`Related US. Application Data
`
`(60)
`
`Provisional application No. 60/482,161, filed on Jun.
`24, 2003.
`
`Int. Cl.
`
`(51)
`
`(2006.01)
`A61K 31/495
`(2006.01)
`C07D 471/04
`US. Cl.
`....................................... 514/249; 544/350
`Field of Classification Search ................ 514/249;
`544/350
`
`(52)
`(58)
`
`See application file for complete search history.
`
`24 Claims, 5 Drawing Sheets
`
`1of16
`
`|PR2020-01045
`
`Teva EX. 1001
`
`1 of 16
`
`IPR2020-01045
`Teva Ex. 1001
`
`

`

`U.S. Patent
`
`Feb. 5, 2008
`
`Sheet 1 0f 5
`
`US 7,326,708 B2
`
`L!)
`I"?
`
`OF
`
`)
`
`1.0
`N
`
`f“
`"‘.
`9/
`E C]
`8 E .—N u.
`
`In
`
`2
`
`In
`
`D
`C:
`Ln
`N
`
`O
`C:
`:3
`N
`
`O
`O
`Ln
`‘—
`
`O
`O
`0
`1—
`
`O
`0
`In
`
`O
`
`(smnoo) Ausmmu
`
`2 of 16
`
`IPR2020-O1045
`
`Teva EX. 1001
`
`2 of 16
`
`IPR2020-01045
`Teva Ex. 1001
`
`

`

`U.S. Patent
`
`Feb. 5, 2008
`
`Sheet 2 0f 5
`
`US 7,326,708 B2
`
`PPM FIG.2
`
`20015010050
`
`250
`
`300
`
`3 0f 16
`
`|PR2020-01045
`
`Teva EX. 1001
`
`3 of 16
`
`IPR2020-01045
`Teva Ex. 1001
`
`

`

`U.S. Patent
`
`Feb. 5, 2008
`
`Sheet 3 0f 5
`
`US 7,326,708 B2
`
`E
`
`0')
`
`E?
`LL
`
`OONl
`
`O EI
`
`g
`
`l
`
`Ot
`
`o I
`
`4 of 16
`
`|PR2020-01045
`
`Teva EX. 1001
`
`4 of 16
`
`IPR2020-01045
`Teva Ex. 1001
`
`

`

`U.S. Patent
`
`Feb. 5, 2008
`
`Sheet 4 0f 5
`
`US 7,326,708 B2
`
`183.1
`
`140
`
`
`
`TEMPERATURE(°c)
`
`FIG4
`
`IIIIIIIEII
`
` 160
`IIIIIIENII
`
` 120
`IIIIIIIHII
`
`IHIIIIIHII
`
`
`IIII
`
` DELTAY=3.3647%
`
`
`”III
` 60
`
`100
`
`80
`
`40
`
`(.D
`*‘I
`0
`
`on:
`CO
`CO
`F‘—
`
`In
`CD
`O!
`
`C:
`a!
`O!
`
`to
`co
`05
`
`ca
`no
`O)
`
`In
`N
`O)
`
`0.
`1‘-
`O)
`
`m
`CD
`O!
`
`02“
`I!)
`O)
`
`%.LH313M
`
`5 of 16
`
`|PR2020-01045
`
`Teva EX. 1001
`
`5 of 16
`
`IPR2020-01045
`Teva Ex. 1001
`
`

`

`US. Patent
`
`Feb. 5, 2008
`
`Sheet 5 of 5
`
`US 7,326,708 B2
`
`250
`
`150 (°C)
`5% L0
`E9
`E U.
`8 f:
`
`200
`
`
`5?:
`
`O
`
`i
`
`l
`I
`(b/M) MO'U MH
`
`l
`
`2'
`
`6 of 16
`
`|PR2020-01045
`
`Teva EX. 1001
`
`6 of 16
`
`IPR2020-01045
`Teva Ex. 1001
`
`

`

`US 7,326,708 B2
`
`1
`PHOSPHORIC ACID SALT OF A
`DIPEPTIDYL PEPTIDASE-IV INHIBITOR
`
`CROSS-REFERENCE TO RELATED
`APPLICATIONS
`
`The present invention is related to US. provisional appli-
`cation Ser. No. 60/482,161, filed Jun. 24, 2003, the contents
`of which are hereby incorporated by reference.
`
`FIELD OF THE INVENTION
`
`The present invention relates to a particular salt of a
`dipeptidyl peptidase-IV inhibitor. More particularly,
`the
`invention relates to a dihydrogenphosphate salt of 4-oxo-4-
`[3-(trifluoromethyl)-5, 6-dihydro[ l ,2,4]triazolo[4,3 -a]
`pyrazin—7(8H)-yl] - 1 -(2,4,5 -trifluorophenyl)butan-2 -amine,
`which is a potent inhibitor of dipeptidyl peptidase-IV. This
`novel salt and crystalline hydrates thereof are useful for the
`treatment and prevention of diseases and conditions for
`which an inhibitor of dipeptidyl peptidase-IV is indicated, in
`particular Type 2 diabetes, obesity, and high blood pressure.
`The invention further concerns pharmaceutical composi-
`tions comprising the dihydrogenphosphate salt and crystal-
`line hydrates thereof useful to treat Type 2 diabetes, obesity,
`and high blood pressure as well as processes for preparing
`the dihydrogenphosphate salt and crystalline hydrates
`thereof and their pharmaceutical compositions.
`
`BACKGROUND OF THE INVENTION
`
`30
`
`2
`
`4-oxo-4-[3-(trifluoromethyl)-5,6-dihydro[ l ,2,4]
`inhibitor
`triazolo[4,3-a]pyrazin—7(8H)-yl]-l-(2,4,5-trifluorophenyl)
`butan-2-amine and crystalline hydrates thereof, in particular
`a crystalline monohydrate. The dihydrogenphosphate salt
`and crystalline hydrates of the present invention have advan-
`tages in the preparation of pharmaceutical compositions of
`4-oxo-4-[3-(trifluoromethyl)-5,6-dihydro[l,2,4]triazolo[4,
`3 -a]pyrazin—7(8H)-yl] - 1 -(2,4,5 -trifluorophenyl)butan-2-
`amine, such as ease of processing, handling, and dosing. In
`particular,
`they exhibit
`improved physical and chemical
`stability, such as stability to stress, high temperatures and
`humidity, as well as improved physicochemical properties,
`such as solubility and rate of solution, rendering them
`particularly suitable for the manufacture of various pharma-
`ceutical dosage forms. The invention also concerns pharma-
`ceutical compositions containing the novel salt and hydrates
`as well as methods for using them as DP-IV inhibitors, in
`particular for the prevention or treatment of Type 2 diabetes,
`obesity, and high blood pressure.
`
`BRIEF DESCRIPTION OF THE FIGURES
`
`10
`
`15
`
`20
`
`FIG. 1 is a characteristic X-ray diffraction pattern of the
`crystalline monohydrate of the dihydrogenphosphate salt of
`structural formula II.
`
`25
`
`FIG. 2 is a carbon-l3 cross-polarization magic-angle
`spinning (CPMAS) nuclear magnetic resonance (NMR)
`spectrum of the crystalline monohydrate of the dihydrogen-
`phosphate salt of structural formula II.
`FIG. 3 is a fluorine-l9 magic-angle spinning (MAS)
`nuclear magnetic resonance (NMR) spectrum of the crys-
`talline monohydrate of the dihydrogenphosphate salt of
`structural formula II.
`
`35
`
`FIG. 4 is a typical thermogravimetric analysis (TGA)
`curve of the crystalline monohydrate dihydrogenphosphate
`salt of structural formula II.
`
`40
`
`45
`
`50
`
`55
`
`60
`
`65
`
`FIG. 5 is a typical differential scanning calorimetry (DSC)
`curve of the crystalline monohydrate of the dihydrogenphos-
`phate salt of structural formula II.
`
`DETAILED DESCRIPTION OF THE
`INVENTION
`
`This invention provides a new monobasic dihydrogen-
`phosphate salt of 4-oxo-4-[3-(trifluoromethyl)-5,6-dihy-
`dro[l
`,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl]-l-(2,4,5-trifluo-
`rophenyl) butan—2-amine of the following structural formula
`I:
`
`(I)
`
`or a crystalline hydrate thereof. In particular, the instant
`invention provides a crystalline monohydrate of the dihy-
`drogenphosphate salt of formula I.
`The dihydrogenphosphate salt of the present invention has
`a center of asymmetry at
`the stereogenic carbon atom
`
`Inhibition of dipeptidyl peptidase-IV (DP-IV), an enzyme
`that inactivates both glucose-dependent insulinotropic pep-
`tide (GIP) and glucagon-like peptide 1 (GLP-l), represents
`a novel approach to the treatment and prevention of Type 2
`diabetes, also known as non-insulin dependent diabetes
`mellitus (NIDDM). The therapeutic potential of DP-IV
`inhibitors for the treatment of Type 2 diabetes has been
`reviewed: C. F. Deacon and J. J. Holst, “Dipeptidyl pepti-
`dase IV inhibition as an approach to the treatment and
`prevention of Type 2 diabetes: a historical perspective,”
`Biochem. Biophys. Res. Commun, 294:
`l-4 (2000); K.
`Augustyns, et al., “Dipeptidyl peptidase IV inhibitors as new
`therapeutic agents for the treatment of Type 2 diabetes,”
`Expert. Opin. The}: Patents, 13: 499-510 (2003); and D. J.
`Drucker, “Therapeutic potential of dipeptidyl peptidase IV
`inhibitors for the treatment of Type 2 diabetes,” Expert Opin.
`Investig. Drugs, 12: 87-100 (2003).
`WC 03/004498 (published 16 Jan. 2003), assigned to
`Merck & Co., describes a class of beta-amino tetrahydrot-
`riazolo[4,3-a]pyrazines, which are potent inhibitors of DP-
`IV and therefore useful for the treatment of Type 2 diabetes.
`Specifically disclosed in WC 03/004498 is 4-oxo-4-[3-
`(trifluoromethyl)-5 ,6-dihydro [l ,2,4]triazolo [4,3 -a]pyrazin-
`7(8H)-yl]— l -(2,4,5-trifluorophenyl)butan-2-amine. Pharma-
`ceutically acceptable salts of this compound are generically
`encompassed within the scope of WO 03/004498.
`However,
`there is no specific disclosure in the above
`reference of the newly discovered monobasic dihydrogen-
`phosphate salt of 4-oxo-4-[3-(trifluoromethyl)-5,6-dihydro
`[l,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl]-l-(2,4,5-trifluo-
`rophenyl)butan-2-amine of structural formula I below.
`
`SUMMARY OF THE INVENTION
`
`The present invention is concerned with a novel dihydro-
`genphosphate salt of the dipeptidyl peptidase-IV (DP-IV)
`
`70f16
`
`|PR2020-01045
`
`Teva EX. 1001
`
`7 of 16
`
`IPR2020-01045
`Teva Ex. 1001
`
`

`

`US 7,326,708 B2
`
`3
`indicated with an * and can thus occur as a racemate,
`racemic mixture, and single enantiomers, with all isomeric
`forms being included in the present invention. The separate
`enantiomers, substantially free of the other, are included
`within the scope of the invention, as well as mixtures of the
`two enantiomers.
`
`One embodiment of the present invention provides the
`dihydrogenphosphate salt of (2R)-4-oxo-4-[3-(trifluorom-
`ethyl)-5 ,6-dihydro[ 1 ,2,4]triazolo [4,3 -a]pyrazin-7 (8H)-yl] -
`l-(2,4,5-triflorophenyl) butan—2-amine of structural formula
`II:
`
`5
`
`10
`
`(11)
`
`15
`
`20
`
`25
`
`30
`
`or a crystalline hydrate thereof.
`A second embodiment of the present invention provides
`the dihydrogenphosphate salt of (2S)-4-oxo-4-[3-(trifluo-
`romethyl)-5 ,6-dihydro [1 ,2,4]triazolo [4,3 -a]pyrazin-7 (8H)-
`yl]-1-(2,4,5-trifluorophenyl) butan-2-amine of structural for-
`mula III:
`
`(111)
`
`35
`
`
`
`or a crystalline hydrate thereof.
`More specifically, the dihydrogenphosphate salt of the
`present invention is comprised of one molar equivalent of
`mono-protonated 4-oxo-4-[3-(trifluoromethyl)-5,6-dihydro
`[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl]-1-(2,4,5-trifluo-
`rophenyl)butan-2-amine cation and one molar equivalent of
`dihydrogenphosphate (biphosphate) anion.
`the
`In a further embodiment of the present invention,
`dihydrogenphosphate salt of structural formulae I-III is a
`crystalline hydrate. In one class of this embodiment, the
`crystalline hydrate is a crystalline monohydrate.
`A further embodiment of the present invention provides
`the dihydrogenphosphate salt drug substance of structural
`formulae I-III that comprises the crystalline monohydrate
`present
`in a detectable amount. By “drug substance” is
`meant the active pharmaceutical ingredient (“API”). The
`amount of crystalline monohydrate in the drug substance can
`be quantified by the use of physical methods such as X-ray
`powder diffraction, solid-state fluorine-19 magic-angle spin-
`ning (MAS) nuclear magnetic resonance spectroscopy,
`solid-state carbon-13 cross-polarization magic-angle spin-
`ning (CPMAS) nuclear magnetic resonance spectroscopy,
`
`40
`
`45
`
`50
`
`55
`
`60
`
`65
`
`4
`
`solid state Fourier-transform infrared spectroscopy, and
`Raman spectroscopy. In a class of this embodiment, about
`5% to about 100% by weight of the crystalline monohydrate
`is present in the drug substance. In a second class of this
`embodiment, about 10% to about 100% by weight of the
`crystalline monohydrate is present in the drug substance. In
`a third class of this embodiment, about 25% to about 100%
`by weight of the crystalline monohydrate is present in the
`drug substance. In a fourth class of this embodiment, about
`50% to about 100% by weight of the crystalline monohy-
`drate is present in the drug substance. In a fifth class of this
`embodiment, about 75% to about 100% by weight of the
`crystalline monohydrate is present in the drug substance. In
`a sixth class of this embodiment, substantially all of the
`dihydrogenphosphate salt drug substance is the crystalline
`monohydrate of the present invention, i.e., the dihydrogen-
`phosphate salt drug substance is substantially phase pure
`monohydrate.
`The crystalline dihydrogenphosphate salt of the present
`invention exhibits pharmaceutic advantages over the free
`base and the previously disclosed hydrochloride salt (WO
`03/004498) in the preparation of a pharmaceutical drug
`product containing the pharmacologically active ingredient.
`In particular, the enhanced chemical and physical stability of
`the crystalline dihydrogenphosphate salt monohydrate con-
`stitute advantageous properties in the preparation of solid
`pharmaceutical dosage forms containing the pharmacologi-
`cally active ingredient.
`The dihydrogenphosphate salt of the present invention,
`which exhibits potent DP-IV inhibitory properties,
`is par-
`ticularly useful for the prevention or treatment of Type 2
`diabetes, obesity, and high blood pressure.
`Another aspect of the present invention provides a method
`for the prevention or treatment of clinical conditions for
`which an inhibitor of DP-IV is indicated, which method
`comprises administering to a patient in need of such pre-
`vention or treatment a prophylactically or therapeutically
`effective amount of the dihydrogenphosphate salt of struc-
`tural formula I or a hydrate thereof, in particular the crys-
`talline monohydrate thereof. Such clinical conditions
`include diabetes, in particular Type 2 diabetes, hyperglyce-
`mia, insulin resistance, and obesity.
`The present invention also provides the use of the dihy-
`drogenphosphate salt of structural formula I or a hydrate
`thereof, in particular the crystalline monohydrate, for the
`manufacture of a medicament for the prevention or treat-
`ment of clinical conditions for which an inhibitor of DP-IV
`is indicated.
`
`The present invention also provides pharmaceutical com-
`positions comprising the dihydrogenphosphate salt of struc-
`tural formula I or a hydrate thereof, in particular the crys-
`talline monohydrate,
`in association with one or more
`pharrnaceutically acceptable carriers or excipients. In one
`embodiment the pharmaceutical composition comprise a
`therapeutically effective amount of the active pharmaceuti-
`cal ingredient in admixture with pharrnaceutically accept-
`able excipients wherein the active pharmaceutical ingredient
`comprises a detectable amount of the crystalline monohy-
`drate of the present invention. In a second embodiment the
`pharmaceutical composition comprise a therapeutically
`effective amount of the active pharmaceutical ingredient in
`admixture with pharrnaceutically acceptable excipients
`wherein the active pharmaceutical
`ingredient comprises
`about 5% to about 100% by weight of the crystalline
`monohydrate of the present invention. In a class of this
`second embodiment, the active pharmaceutical ingredient in
`such compositions comprises about 10% to about 100% by
`
`80f16
`
`|PR2020-01045
`
`Teva EX. 1001
`
`8 of 16
`
`IPR2020-01045
`Teva Ex. 1001
`
`

`

`US 7,326,708 B2
`
`5
`weight of the crystalline monohydrate. In a second class of
`this embodiment, the active pharmaceutical ingredient in
`such compositions comprises about 25% to about 100% by
`weight of the crystalline monohydrate. In a third class of this
`embodiment, the active pharmaceutical ingredient in such
`compositions comprises about 50% to about 100% by
`weight of the crystalline monohydrate. In a fourth class of
`this embodiment, the active pharmaceutical ingredient in
`such compositions comprises about 75% to about 100% by
`weight of the crystalline monohydrate. In a fifth class of this
`embodiment, substantially all of the active pharmaceutical
`ingredient is the crystalline dihydrogenphosphate salt mono-
`hydrate of the present invention, i.e., the active pharmaceu-
`tical ingredient is substantially phase pure dihydrogenphos-
`phate salt monohydrate.
`The compositions in accordance with the invention are
`suitably in unit dosage forms such as tablets, pills, capsules,
`powders, granules, sterile solutions or suspensions, metered
`aerosol or liquid sprays, drops, ampoules, auto-injector
`devices or suppositories. The compositions are intended for
`oral, parenteral, intranasal, sublingual, or rectal administra-
`tion, or for administration by inhalation or insufilation.
`Formulation of the compositions according to the invention
`can conveniently be effected by methods known from the
`art, for example, as described in Remington ’s Pharmaceu—
`tical Sciences, 17th ed., 1995.
`The dosage regimen is selected in accordance with a
`variety of factors including type, species, age, weight, sex
`and medical condition of the patient; the severity of the
`condition to be treated; the route of administration; and the
`renal and hepatic function of the patient. An ordinarily
`skilled physician, veterinarian, or clinician can readily deter-
`mine and prescribe the effective amount of the drug required
`to prevent, counter or arrest the progress of the condition.
`Oral dosages of the present invention, when used for the
`indicated effects, will range between about 0.01 mg per kg
`of body weight per day (mg/kg/day) to about 100 mg/kg/day,
`preferably 0.01 to 10 mg/kg/day, and most preferably 0.1 to
`5.0 mg/kg/day. For oral administration, the compositions are
`preferably provided in the form of tablets containing 0.01,
`0.05, 0.1, 0.5, 1.0, 2.5, 5.0, 10.0, 15.0, 25.0, 50.0, 100, 200,
`and 500 milligrams of the active ingredient for the symp-
`tomatic adjustment of the dosage to the patient to be treated.
`A medicament typically contains from about 0.01 mg to
`about 500 mg of the active ingredient, preferably, from about
`1 mg to about 200 mg of active ingredient. lntravenously, the
`most preferred doses will range from about 0.1 to about 10
`mg/kg/minute during a constant rate infusion. Advanta-
`geously, the crystalline forms of the present invention may
`be administered in a single daily dose, or the total daily
`dosage may be administered in divided doses of two, three
`or four times daily. Furthermore, the crystalline forms of the
`present invention can be administered in intranasal form via
`topical use of suitable intranasal vehicles, or via transdermal
`routes, using those forms of transdermal skin patches well
`known to those of ordinary skill in the art. To be adminis-
`tered in the form of a transdermal delivery system,
`the
`dosage administration will, of course, be continuous rather
`than intermittent throughout the dosage regimen.
`In the methods of the present invention, the dihydrogen-
`phosphate salt and crystalline hydrates herein described in
`detail can form the active pharmaceutical ingredient, and are
`typically administered in admixture with suitable pharma-
`ceutical diluents, excipients or carriers (collectively referred
`to herein as ‘carrier’ materials) suitably selected with respect
`to the intended form of administration, that is, oral tablets,
`capsules, elixirs, syrups and the like, and consistent with
`conventional pharmaceutical practices.
`
`5
`
`10
`
`15
`
`20
`
`25
`
`30
`
`35
`
`40
`
`45
`
`50
`
`55
`
`60
`
`65
`
`6
`For instance, for oral administration in the form of a tablet
`or capsule,
`the active pharmaceutical
`ingredient can be
`combined with an oral, non-toxic, pharrnaceutically accept-
`able, inert carrier such as lactose, starch, sucrose, glucose,
`methyl cellulose, magnesium stearate, dicalcium phosphate,
`calcium sulfate, mannitol, sorbitol and the like; for oral
`administration in liquid form,
`the active pharmaceutical
`ingredient can be combined with any oral, non-toxic, phar-
`maceutically acceptable inert carrier such as ethanol, glyc-
`erol, water and the like. Moreover, when desired or neces-
`sary, suitable binders, lubricants, disintegrating agents and
`coloring agents can also be incorporated into the mixture.
`Suitable binders include starch, gelatin, natural sugars such
`as glucose or beta-lactose, corn sweeteners, natural and
`synthetic gums such as acacia, tragacanth or sodium algi-
`nate, carboxymethylcellulose, polyethylene glycol, waxes
`and the like. Lubricants used in these dosage forms include
`sodium oleate, sodium stearate, magnesium stearate, sodium
`benzoate, sodium acetate, sodium chloride and the like.
`Disintegrators include, without
`limitation, starch, methyl
`cellulose, agar, bentonite, xanthan gum and the like.
`The dihydrogenphosphate salt of structural formula I and
`the crystalline monohydrate have been found to possess a
`high solubility in water, rendering it especially amenable to
`the preparation of formulations, in particular intranasal and
`intravenous formulations, which require relatively concen-
`trated aqueous solutions of active ingredient. The solubility
`of the crystalline dihydrogenphosphate salt monohydrate of
`formula I in water has been found to be about 72 mg/mL.
`According to a further aspect, the present invention pro-
`vides a process for the preparation of the dihydrogenphos-
`phate salt of formula I, which process comprises reacting
`4-oxo-4-[3-(trifluoromethyl)-5,6-dihydro[1,2,4]triazolo[4,
`3 -a]pyrazin—7(8H)-yl]—1-(2,4,5 -trifluoromethyl)butan-2-
`amine of structural formula IV below:
`
`F
`
`(1V)
`
`CF3
`
`with approximately one equivalent of phosphoric acid in a
`suitable C1-C5 alkanol, such as methanol, ethanol, isopropyl
`alcohol (IPA), and isoamyl alcohol (1AA) or aqueous C1-C5
`alkanol. The reaction is carried out at a temperature range of
`about 25 ° C. to about 80 ° C. The phosphoric acid solution
`can be added to a solution of the amine, or the addition can
`be performed in the reverse direction. The crystalline dihy-
`drogenphosphate salt monohydrate is obtained by crystalli-
`zation from an aqueous C1-C5 alkanol solution of the dihy-
`drogenphosphate salt as described below.
`
`General Methods for Crystallizing the Monohydrate
`of the Dihydrogenphosphate Salt of Structural
`Formula I
`
`(a) In Ethanol/Water System at 25° C.:
`(1) crystallization from a mixture of compound I in ethanol
`and water, such that the water concentration is above 31
`weight percent,
`(2) recovering the resultant solid phase, and
`(3) removing the solvent therefrom.
`
`90f16
`
`|PR2020-01045
`
`Teva EX. 1001
`
`9 of 16
`
`IPR2020-01045
`Teva Ex. 1001
`
`

`

`US 7,326,708 B2
`
`7
`(b) In Isoamyl Alcohol (IAA)/Water System at 25° C.:
`(1) crystallization from a mixture of compound I in IAA and
`water, such that the water concentration is above 2.9
`weight percent;
`(2) recovering the resultant solid phase; and
`(3) removing the solvent therefrom.
`
`(c) In IAA/Water System at 40° C.:
`(1) crystallization from a mixture of compound I in IAA and
`water, such that the water concentration is above 3.6
`weight percent;
`(2) recovering the resultant solid phase; and
`(3) removing the solvent therefrom
`
`(d) In IAA/Water System at 60° C.:
`(1) crystallization from a mixture of compound I in IAA and
`water, such that the water concentration is above 4.5
`weight percent;
`(2) recovering the resultant solid phase; and
`(3) removing the solvent therefrom.
`
`(e) In Isopropyl Alcohol (IPA)/Water System at 25° C.:
`(1) crystallization from a mixture of compound I in IPA and
`water, such that the water concentration is above 7.0
`weight percent;
`(2) recovering the resultant solid phase; and
`(3) removing the solvent therefrom
`
`(f) In IPA/Water System at 40° C.:
`(1) crystallization from a mixture of compound I in EPA and
`water, such that the water concentration is above 8.1
`weight percent;
`(2) recovering the resultant solid phase; and
`(3) removing the solvent therefrom.
`
`(g) In IPA/Water System at 75° C.:
`(1) crystallization from a mixture of compound I in IPA and
`water, such that the water concentration is above about 20
`weight percent;
`(2) recovering the resultant solid phase; and
`(3) removing the solvent therefrom.
`The starting compound of structural formula IV can be
`prepared by the procedures detailed in Schemes 1-3 and
`Example 1 below.
`In a still further aspect, the present invention provides a
`method for the treatment and/or prevention of clinical con-
`ditions for which a DP-IV inhibitor is indicated, which
`method comprises administering to a patient in need of such
`prevention or treatment a prophylactically or therapeutically
`effective amount of the salt of Formula I as defined above or
`
`a crystalline hydrate thereof.
`The following non-limiting Examples are intended to
`illustrate the present invention and should not be construed
`as being limitations on the scope or spirit of the instant
`invention.
`
`Compounds described herein may exist as tautomers such
`as keto-enol tautomers. The individual tautomers as well as
`
`mixtures thereof are encompassed with compounds of struc-
`tural formula I.
`
`The term “% enantiomeric excess” (abbreviated “ee”
`shall mean the % major enantiomer less the % minor
`enantiomer. Thus, a 70% enantiomeric excess corresponds
`to formation of 85% of one enantiomer and 15% of the other.
`
`The term “enantiomeric excess” is synonymous with the
`term “optical purity.”
`
`10
`
`15
`
`20
`
`25
`
`30
`
`35
`
`40
`
`45
`
`50
`
`55
`
`60
`
`65
`
`Step A: Preparation of bishydrazide (1-1)
`Hydrazine (20.1 g, 35 wt% in water, 0.22 mol) was mixed
`with 310 mL of acetonitrile. 31.5 g of ethyl trifluoroacetate
`(0.22 mol) was added over 60 min. The internal temperature
`was increased to 25° C. from 14° C. The resulting solution
`was aged at 22-25° C. for 60 min. The was cooled to 7° C.
`17.9 g of 50 wt % aqueous NaOH (0.22 mol) and 25.3 g of
`chloroacetyl chloride (0.22 mol) were added simultaneously
`over 130 min at a temperature below 16° C. When the
`reaction was complete, the mixture was vacuum distilled to
`
`10of16
`
`|PR2020-01045
`
`Teva EX. 1001
`
`8
`EXAMPLE
`
`oH3Po4 onzo
`
`NH2
`
`0
`
`N /
`
`CF3
`
`(2R)-4-oxo -4- [3 -(trifluoromethyl)-5 ,6-dihydro [1 ,2,4]
`triazolo[4,3-a]pyrazin-7(8H)—yl]-1-(2,4,5 -trifluo-
`rophenyl)butan—2 -amine dihydrogenpho sphate
`monohydrate
`
`Preparation of 3-(trifluoromethyl)-5,6,7,8-tetrahydro[1,2,
`41]triazolo[4,3-a]pyrazine hydrochloride (1-4)
`
`Schemei
`
`1. CF3COOEt, CH3CN
`NHZNHZ —»
`2. C1COCH2C1,NaOH
`
`CH C12
`
`N
`
`N/
`H
`
`o
`
`POC13
`CH3CN
`
`o i
`
`F3C
`
`1—1
`N—N
`A %
`o
`1_2
`
`F3C
`
`o
`N\ )k
`PIN/\K g
`K/NH
`
`NHZ
`CHZCl HZN/\/—>
`MeOH
`
`M
`
`CF3
`
`MeOH,HCl,55°C.—>
`
`HCl
`
`N
`
`PIN/\f \N
`K/N\<
`
`CF3
`
`14
`
`10 of 16
`
`IPR2020-01045
`Teva Ex. 1001
`
`

`

`US 7,326,708 B2
`
`10
`
`1H—NMR (400 MHZ, DMSO-d6): a 3.6 (t, 2H), 4.4 (t, 2H),
`4.6 (s, 2H), and 10.6 (b, 2H) ppm; l3C-NMR (100 MHZ,
`DMSO-d6): a: 39.4, 39.6, 41.0, 118.6 (q, 1:325 HZ), 1429
`(q, J:50 HZ), and 148.8 ppm.
`
`Schemel
`
`F
`
`10
`
`F
`
`O
`
`o
`
`0
`
`9
`remove water and ethanol at 27~30° C. and under 26 ~27 in
`
`Hg vacuum. During the distillation, 720 mL of acetonitrile
`was added slowly to maintain constant volume (approxi-
`mately 500 mL). The slurry was filtered to remove sodium
`chloride. The cake was rinsed with about 100 mL of aceto-
`
`nitrile. Removal of the solvent afforded bis-hydraZide 1-1
`(43.2 g, 96.5% yield, 94.4 area % pure by HPLC assay).
`1H-NMR (400 MHZ, DMSO-d6): 6 4.2 (s, 2H), 10.7 (s,
`1H), and 11.6 (s, 1H) ppm. l3C-NMR (100 MHZ, DMSO-
`d6): 6 41.0, 116.1 (q, J:362 HZ), 155.8 (q, J:50 HZ), and
`165.4 ppm.
`
`Step B: Preparation of 5-(trifluoromethyl)-2-(chlorom-
`ethyl)-1.3.4-oxadiazole (1 -2)
`BishydraZide 1-1 from Step A (43.2 g, 0.21 mol) in ACN
`(82 mL) was cooled to 5° C. Phosphorus oxychloride (32.2
`g, 0.21 mol) was added, maintaining the temperature below
`10° C. The mixture was heated to 80° C. and aged at this
`temperature for 24 h until HPLC showed less than 2 area %
`of 1-1. In a separate vessel, 260 mL of lPAc and 250 mL of
`water were mixed and cooled to 0° C. The reaction slurry
`was charged to the quench keeping the internal temperature
`below 10° C. After the addition, the mixture was agitated
`vigorously for 30 min, the temperature was increased to
`room temperature and the aqueous layer was cut. The
`organic layer was then washed with 215 mL of water, 215
`mL of 5 wt % aqueous sodium bicarbonate and finally 215
`mL of 20 wt % aqueous brine solution. HPLC assay yield
`after work up was 86-92%. Volatiles were removed by
`distillation at 75-80 mm Hg, 55° C. to afford an oil which
`could be used directly in Step C without further purification.
`Otherwise the product can be purified by distillation to
`afford 1-2 in 70-80% yield.
`1H-NMR (400 MHZ, CDCl3): 6 4.8 (s, 2H) ppm. 13C-
`NMR (100 MHZ, CDCl3): 6 32.1, 115.8 (q, J:337 HZ), 156.2
`(q, J:50 HZ), and 164.4 ppm.
`
`Step C: Preparation of N-[(2Z)-piperaZin-2-ylidene]trifluo-
`roacetohydraZide (1-3)
`To a solution of ethylenediamine (33.1 g, 0.55 mol) in
`methanol (150 mL) cooled at —20° C. was added distilled
`oxadiazole 1-2 from Step B (29.8 g, 0.16 mol) while keeping
`the internal temperature at —20° C. After the addition was
`complete, the resulting slurry was aged at —20° C. for 1 h.
`Ethanol (225 mL) was then charged and the slurry slowly
`warmed to —5° C. After 60 min at —5° C., the slurry was
`filtered and washed with ethanol (60 mL) at —5° C. Amidine
`1-3 was obtained as a white solid in 72% yield (24.4 g, 99.5
`area wt % pure by HPLC).
`1H-NMR (400 MHZ, DMSO-d6): 6 2.9 (t, 2H), 3.2 (t, 2H),
`3.6 (s, 2H), and 8.3 (b, 1H) ppm. 13C-NMR (100 MHZ,
`DMSO-d6): 6 40.8, 42.0,43.3, 119.3 (q, J:350 HZ), 154.2,
`and 156.2 (q, J:38 HZ) ppm.
`
`Step D: Preparation of 3-(trifluoromethyl)-5,6,7,8-tetrahy-
`dro[1,2,4]triazolo[4.3-a]pyraZine hydrochloride (1-4)
`A suspension of amidine 1-3 (27.3 g, 0.13 mol) in 110 mL
`of methanol was warmed to 55° C. 37% Hydrochloric acid
`(11.2 mL, 0.14 mol) was added over 15 min at this tem-
`perature. During the addition, all solids dissolved resulting
`in a clear solution. The reaction was aged for 30 min. The
`solution was cooled down to 20° C. and aged at
`this
`temperature until a seed bed formed (10 min to 1 h). 300 mL
`of MTBE was charged at 20° C. over 1 h. The resulting
`slurry was cooled to 2° C., aged for 30 min and filtered.
`Solids were washed with 50 mL of ethanol:MTBE (1 :3) and
`dried under vacuum at 45° C. Yield of triazole 1-4 was 26.7
`
`g (99.5 area wt % pure by HPLC).
`
`15
`
`20
`
`25
`
`F
`
`F
`
`30
`
`35
`
`F
`
`40
`
`45
`
`50
`
`55
`
`60
`
`65
`
`OH
`
`0 OK—>
`
`tBuCOCl, iPerEt,
`DMAP, DMAc
`HC1
`
`F
`
`F
`
`2—1
`
`\
`
`Elk/EN
`
`CF3
`
`OH
`
`0
`
`o
`
`2-2
`
`O
`
`O
`
`
`NH40Ac
`MeOH
`
`N
`
`N
`/ \
`N
`
`N\<CF3
`
`2-3
`
`NH2 0
`
`[Rh(°0d)C112,
`
`R, S - t-Bu Josiphos,—>
`\ N/YN\
`K/N\<N H2, MeOH, 200 psi, 50° C.
`CF3
`
`2-4
`
`F
`
`F
`
`F
`
`F
`
`F
`
`F
`
`F
`
`NH2
`
`0
`
`2-5
`
`N
`
`Ny \N
`K/N\<
`
`Step A: Preparation of 4-oxo-4-[3-(trifluoromethyl)-5,6-di-
`hydro[1,2,4]triazolo[4,3-a]pyraZin-7(8H)-yl]—1-(2,4,5-trif-
`luorophenyl)butan-2-one (2-3)
`2,4,5-Trifluorophenylacetic acid (2-1 (150 g, 0.789 mol),
`Meldrum’s acid (125 g, 0.868 mol), and 4-(dimethylamino)
`pyridine (DMAP) (7.7 g, 0063 mol) were charged into a 5
`L three-neck flask. N,N—Dimethylacetamide (DMAc) (525
`mL) was added in one portion at room temperature to
`
`11 of16
`
`|PR2020-01045
`
`Teva EX. 1001
`
`11 of 16
`
`IPR2020-01045
`Teva Ex. 1001
`
`

`

`11
`
`12
`
`US 7,326,708 B2
`
`dissolve the solids. N,N—diisopropylethylamine (282 mL,
`1.62 mol) was added in one portion at room temperature
`while maintaining the temperature below 40° C. Pivaloyl
`chloride (107 mL, 0.868 mol) was added dropwise over 1 to
`2 h while maintaining the temperature between 0 and 5° C.
`The reaction mixture was aged at 5° C. for 1 h. Triazole
`hydrochloride 14 (180 g, 0.789 mol) was added in one
`portion at 40-50° C. The reaction solution was aged at 70°
`C. for several h. 5% Aqueous sodium hydrogencarbonate
`solution (625 mL) was then added dropwise at 20-45° C.
`The batch was seeded and aged at 20-30° C. for 1-2 h. Then
`an additional 525 mL of 5% aqueous sodium hydrogencar-
`bonate solution was added dropwise over 2-3 h. After aging
`several h at room temperature, the slurry was cooled to 0-5°
`C. and aged 1 h before filtering the solid. The wet cake was
`displacement-washed with 20% aqueous DMAc (300 mL),
`followed by an additional
`two batches of 20% aqueous
`DMAc (400 mL), and finally water (400 mL). The cake was
`suction-dried at room temperature. The isolated yield of final
`product 2-3 was 89%.
`
`Step B: Preparation of (2Z)-4-oxo-4-[3-(trifluoromethyl)-5,
`6-dihydro[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl-]—1-(2,4,5-
`trifluorophenyl)but-2-en-2-amine (2-4)
`A 5 L round-bottom flask was charged with methanol (100
`mL), the ketoamide 2-3 (200 g), and ammonium acetate
`(110.4 g). Methanol (180 mL) and 28% aqueous ammonium
`hydroxide (58.6 mL) were then added keeping the tempera-
`ture below 30° C. dur