This application claims priority from U.S. provisional application No.61/073,399, filed June 18, 2008, filed on 18.6.2008, which application is incorporated herein by reference in its entirety.
Summary of The Invention
The present invention includes a process for preparing a compound of formula I:
wherein: a is an optionally substituted heterocycle; r1Is N (R)1A)2Hydrogen, hydroxy, or optionally substituted alkyl, aryl, alkylaryl, arylalkyl, heteroalkyl, heterocycle, alkylheterocycle, or heterocycloalkyl; and each R1AIndependently hydrogen, or optionally substituted alkyl, aryl, alkylaryl, arylalkyl, heteroalkyl, heterocycle, alkylheterocycle or heterocycloalkyl.
Detailed description of the invention
Formula I encompasses S1P lyase inhibitors believed to be useful in the treatment of diseases and disorders such as rheumatoid arthritis. See U.S. patent application 12/038,872 to Augeri et al, filed on 28/2/2008. The present invention encompasses synthetic methods suitable for large scale (e.g., kilogram scale) production of these compounds.
Definition of
Unless otherwise stated, the term "alkenyl" refers to straight, branched, and/or cyclic hydrocarbons containing from 2 to 20 (e.g., 2 to 10 or 2 to 6) carbon atoms and including at least one carbon-carbon double bond. Representative alkenyl moieties include vinyl, allyl, 1-butenyl, 2-butenyl, isobutenyl, 1-pentenyl, 2-pentenyl, 3-methyl-1-butenyl, 2-methyl-2-butenyl, 2, 3-dimethyl-2-butenyl, 1-hexenyl, 2-hexenyl, 3-hexenyl, 1-heptenyl, 2-heptenyl, 3-heptenyl, 1-octenyl, 2-octenyl, 3-octenyl, 1-nonenyl, 2-nonenyl, 3-nonenyl, 1-decenyl, 2-decenyl, and 3-decenyl.
Unless otherwise stated, the term "alkoxy" means-O-alkyl. Examples of alkoxy groups include, but are not limited to, -OCH3，-OCH2CH3，-O(CH2)2CH3，-O(CH2)3CH3，-O(CH2)4CH3and-O (CH)2)5CH3. The term "lower alkoxy" refers to-O- (lower alkyl).
Unless otherwise stated, the term "alkyl" refers to straight, branched, and/or cyclic ("cycloalkyl") hydrocarbons containing 1 to 20 (e.g., 1 to 10 or 1 to 4) carbon atoms. Alkyl moieties containing 1 to 4 carbons are referred to as "lower alkyl". Examples of alkyl groups include methyl, ethyl, propyl, isopropyl, n-butyl, t-butyl, isobutyl, pentyl, hexyl, isohexyl, heptyl, 4, 4-dimethylpentyl, octyl, 2, 2, 4-trimethylpentyl, nonyl, decyl, undecyl and dodecyl. Cycloalkyl moieties may be monocyclic or polycyclic, examples of which include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and adamantyl. Further examples of alkyl moieties have linear, branched and/or cyclic moieties (e.g., 1-ethyl-4-methyl-cyclohexyl). The term "alkyl" includes saturated hydrocarbons as well as alkenyl and alkynyl moieties.
Unless otherwise stated, the term "alkylaryl" or "alkyl-aryl" refers to an alkyl moiety attached to an aryl moiety.
Unless otherwise stated, the term "alkylheteroaryl" or "alkyl-heteroaryl" refers to an alkyl moiety attached to a heteroaryl moiety.
Unless otherwise stated, the term "alkyl heterocycle" or "alkyl-heterocycle" refers to an alkyl moiety attached to a heterocyclic moiety.
Unless otherwise stated, the term "alkynyl" refers to a straight, branched or cyclic hydrocarbon containing from 2 to 20 (e.g., 2 to 20 or 2 to 6) carbon atoms and containing at least one carbon-carbon triple bond. Representative alkynyl moieties include ethynyl, propynyl, 1-butynyl, 2-butynyl, 1-pentynyl, 2-pentynyl, 3-methyl-1-butynyl, 4-pentynyl, 1-hexynyl, 2-hexynyl, 5-hexynyl, 1-heptynyl, 2-heptynyl, 6-heptynyl, 1-octynyl, 2-octynyl, 7-octynyl, 1-nonynyl, 2-nonynyl, 8-nonynyl, 1-decynyl, 2-decynyl and 9-decynyl.
Unless otherwise stated, the term "aryl" refers to an aromatic ring or an aromatic or partially aromatic ring system composed of carbon and hydrogen atoms. The aryl moiety may comprise multiple rings joined or fused together. Examples of aryl moieties include, but are not limited to, anthracenyl, azulenyl, biphenyl, fluorenyl, indane, indenyl, naphthyl, phenanthryl, phenyl, 1, 2, 3, 4-tetrahydro-naphthalene, and tolyl.
Unless otherwise stated, the term "arylalkyl" or "aryl-alkyl" refers to an aryl moiety attached to an alkyl moiety.
The terms "halogen" and "halo" as used herein refer to fluorine, chlorine, bromine and iodine unless otherwise stated.
Unless otherwise stated, the term "heteroalkyl" refers to an alkyl moiety (e.g., straight-chain, branched-chain, or cyclic) in which at least one of its carbon atoms is replaced with a heteroatom (e.g., N, O or S).
Unless otherwise stated, the term "heteroaryl" refers to an aryl moiety in which at least one of its carbon atoms is replaced with a heteroatom (e.g., N, O or S). Examples include acridinyl, benzimidazolyl, benzofuranyl, benzisothiazolyl, benzisoxazolylAzolyl, benzoquinazolinyl, benzothiazolyl, benzoAzolyl, furyl, imidazolyl, indolyl, isothiazolylAzolyl radical, isoThe group of azolyl groups,(ii) a diazolyl group,oxazolyl, phthalazinyl, pyrazinyl, pyrazolyl, pyridazinyl, pyridyl, pyrimidinyl, pyrrolyl, quinazolinyl, quinolinyl, tetrazolyl, thiazolyl and triazinyl.
Unless otherwise stated, the term "heteroarylalkyl" or "heteroaryl-alkyl" refers to a heteroaryl moiety attached to an alkyl moiety.
Unless otherwise stated, the term "heterocycle" refers to an aromatic, partially aromatic or non-aromatic mono-or polycyclic ring or ring system composed of carbon atoms, hydrogen atoms, and at least one heteroatom (e.g., N, O or S). The heterocyclic ring may include multiple (i.e., two or more) rings that are fused or joined together. Heterocycles include heteroaryls. Examples include benzo [1, 3] dioxolyl, 2, 3-dihydro-benzo [1, 4] dioxin-yl, cinnolinyl, furanyl, hydantoinyl, morpholinyl, oxetanyl, piperazinyl, piperidinyl, pyrrolidinonyl, pyrrolidinyl, tetrahydrofuranyl, tetrahydropyranyl, tetrahydropyridinyl, tetrahydropyrimidinyl, tetrahydrothienyl, tetrahydrothiopyranyl and valerolactam.
Unless otherwise stated, the term "heterocycloalkyl" or "heterocycle-alkyl" refers to a heterocyclic moiety bound to an alkyl moiety.
Unless otherwise stated, the term "hetero-cycloalkyl" refers to a heterocyclic ring that is not aromatic.
Unless otherwise stated, the term "hetero-cycloalkylalkyl" or "hetero-cycloalkyl-alkyl" refers to a hetero-cycloalkyl moiety bonded to an alkyl moiety.
Unless otherwise stated, the term "stereomerically enriched composition" of a compound refers to a mixture of the compound and one or more stereoisomers thereof that comprises more of the compound than one or more stereoisomers of the compound. For example, a stereoisomerically enriched composition of (S) -butan-2-ol includes a mixture of (S) -butan-2-ol and (R) -butan-2-ol present in a ratio of, for example, about 60/40, 70/30, 80/20, 90/10, 95/5, and 98/2.
Unless otherwise stated, the term "stereoisomer mixture" includes racemic mixtures as well as stereoisomerically enriched mixtures (e.g., R/S ═ 30/70, 35/65, 40/60, 45/55, 55/45, 60/40, 65/35, and 70/30).
Unless otherwise stated, the term "stereomerically pure" refers to a composition that comprises one stereoisomer of a compound and is substantially free of other stereoisomers of the compound. For example, a stereomerically pure composition of a compound having one stereocenter is substantially free of the opposite stereoisomer of the compound. A stereomerically pure composition of a compound having two stereocenters is substantially free of other diastereomers of the compound. A stereomerically pure composition of a compound having multiple stereocenters, but which is not depicted or indicated in a stereochemical manner as less than all of its stereocenters, is substantially free of isomers of the compound having different stereochemistry at the stereochemically defined stereocenters. For example, "stereoisomerically pure ((1R) -1, 2-dichloropropyl) benzene" refers to ((1R) -1, 2-dichloropropyl) benzene substantially free of ((1S) -1, 2-dichloropropyl) benzene.
Typical stereoisomerically pure compounds include greater than about 80% by weight of one stereoisomer of the compound and less than about 20% by weight of other stereoisomers of the compound, greater than about 90% by weight of one stereoisomer of the compound and less than about 10% by weight of the other stereoisomers of the compound, greater than about 95% by weight of one stereoisomer of the compound and less than about 5% by weight of the other stereoisomers of the compound, greater than about 97% by weight of one stereoisomer of the compound and less than about 3% by weight of the other stereoisomers of the compound, greater than about 99% by weight of one stereoisomer of the compound and less than about 1% by weight of the other stereoisomers of the compound.
Unless otherwise stated, the term "substituted" when used to describe a chemical structure or moiety refers to a derivative of that structure or moiety in which one or more of its hydrogen atoms is replaced with an atom, chemical moiety or functional group such as, but not limited to: alcohols, aldehydes, alkoxy, alkanoyloxy, alkoxycarbonyl, alkenyl, alkyl (e.g., methyl, ethyl, propyl, t-butyl), alkynyl, alkylcarbonyloxy (-OC (O) alkyl), amide (-C (O) NH-alkyl-or-alkylNHC (O) alkyl), amidino (-C (NH) NH-alkyl-or-C (NR) NH2) Amines (primary, secondary and tertiary amines, such as alkylamino, arylamino, arylalkylamino), aroyl, aryl, aryloxy, azo, carbamoyl (-NHC (O) O-alkyl-or-OC (O) NH-alkyl), carbamyl (e.g., CONH2And CONH-alkyl, CONH-aryl, and CONH-arylalkyl), carbonyl, carboxyl, carboxylic acid anhydride, carboxylic acid chloride, cyano, ester, epoxide, ether (e.g., methoxy, ethoxy), guanidino, halo, haloalkyl (e.g., -CCl)3，-CF3，-C(CF3)3) Heteroalkyl, hemiacetal, imine (primary and secondary), isocyanate, isothiocyanate, ketone, nitrile, nitro, oxygen (i.e., to provide an oxo group), phosphodiester, sulfide, sulfonamide (e.g., SO)2NH2) Sulfones, sulfonyls (including alkylsulfonyl, arylsulfonyl and arylalkylsulfonyl), sulfoxides, thiols (e.g., mercapto, thioether) and ureas (-NHCONH-alkyl-).
In particular embodiments, the term "substituted," when used to describe a chemical structure or moiety, refers to derivatives in which one or more hydrogen atoms of the chemical structure or moiety are replaced with one or more of the following groups: alkoxy, alkoxycarbonylalkyl, amine, aryl, cyano, halo, haloalkyl, hydroxy or nitrile.
Unless otherwise stated, the term "greater than X", where X is a number, has the same meaning as "X or greater than X". Similarly, the term "greater than about X", where X is a number, has the same meaning as "about X or greater than about X".
Unless otherwise stated, the term "less than X", where X is a number, has the same meaning as "X or less than X". Similarly, the term "less than about X", where X is a number, has the same meaning as "about X or less than about X".
Unless otherwise stated, the terms "including" and "comprising" have the same meaning and the terms "including" and "comprises," but are not limited to, "have the same meaning. Similarly, terms such as "and" such as but not limited to "have the same meaning.
Unless otherwise stated, one or more modifiers that immediately precede a series of nouns are considered to apply to each noun. For example, the phrase "optionally substituted alkyl, aryl or heteroaryl" has the same meaning as "optionally substituted alkyl, optionally substituted aryl or optionally substituted heteroaryl".
It should be noted that the chemical moiety that forms part of the larger compound may be referred to herein using the names typically used when the compound moiety is present as a single molecule or when present as a group. For example, the terms "pyridine" and "pyridyl" have the same meaning when used to describe a moiety bound to other chemical moieties. Thus, the two expressions "XOH, wherein X is pyridyl" and "XOH, wherein X is pyridine" are used with the same meaning and include the compounds pyridin-2-ol, pyridin-3-ol and pyridin-4-ol.
It should also be noted that a structure or a portion of a structure is understood to encompass all stereoisomers of it if the stereochemistry of the structure or portion of the structure is not indicated, for example, by bold or dashed lines. Similarly, the name of a compound having one or more chiral centers, without specifying the stereochemistry of such centers, encompasses both pure stereoisomers and mixtures thereof. In addition, any atom shown in the figures having an unsaturated valence is assumed to have enough hydrogen atoms attached to meet the valence requirement. In addition, chemical bonds represented by a solid line parallel to a dashed line encompass both single and double bonds (e.g., aromaticity), provided that valency permits.
Synthesis method
The present invention includes a process for preparing a compound of formula I:
wherein: a is an optionally substituted heterocycle; r1Is N (R)1A)2Hydrogen, hydroxy, or optionally substituted alkyl, aryl, alkylaryl, arylalkyl, heteroalkyl, heterocycle, alkylheterocycle, or heterocycloalkyl; and each R1AIndependently hydrogen, or optionally substituted alkyl, aryl, alkylaryl, arylalkyl, heteroalkyl, heterocycle, alkylheterocycle or heterocycloalkyl. In one embodiment, the compound is prepared by reacting a compound of formula II:
with a compound of formula III:
under conditions sufficient to form a compound of formula I.
In a particular embodiment, A is optionally substitutedDihydro-imidazole, dihydro-isoAzoles, dihydro-pyrazoles, dihydro-thiazoles, dioxolanes, dithiolanes, dithioles, imidazoles, isoxasOxazole, isoOxazolidines, oxathiolanes or pyrazoles.
The conditions sufficient to form the compound of formula I include conducting the reaction in the presence of a solvent and a base. Examples of solvents include alcohols such as methanol, ethanol, isopropanol, and ethers such as tetrahydrofuran, methyl tert-butyl ether, methyl tetrahydrofuran, dimethoxyethane, and mixtures thereof. Examples of the base include metal alkoxides such as sodium methoxide (NaOMe), sodium ethoxide (NaOEt) and potassium tert-butoxide (KO)tBu)。
In a particular method of the invention, a compound of formula i (a):
by reacting a compound of formula ii (a):
and 1-amino-3, 4,5, 6-tetrahydroxyhexane-2-one:
under conditions sufficient to form a compound of formula i (a), wherein: x is CR2，CHR2，N，NR3O or S; y is CR2，CHR2，N，NR3O or S; z is CR2，CHR2，N，NR3O or S; each R2Independently is OR2A，OC(O)R2AHydrogen, halogen, or optionally substituted alkyl, aryl, alkylaryl, arylalkyl, heteroalkyl, heterocycle, alkylheterocycle, or heterocycloalkyl; each R2AIndependently hydrogen, or optionally substituted alkyl, aryl, alkylaryl, arylalkyl, heteroalkyl, heterocycle, alkylheterocycle, or heterocycloalkyl; and each R3Independently hydrogen, or optionally substituted alkyl, aryl, alkylaryl, arylalkyl, heteroalkyl, heterocycle, alkylheterocycle or heterocycloalkyl.
In one embodiment, X is N or O. In one embodiment, Y is N or O. In one embodiment, Z is CH. In one embodiment, R2Is hydrogen or optionally substituted lower alkyl.
In one embodiment, the compound of formula II (a) is isoOxazole-3-carbonitrile:
different from each otherOxazole-3-carbonitrile can be prepared by reacting a compound of formula IV:
with a base inIs enough to provide a differenceOxazole-3-carbonitrile, wherein R is4Is an alkyl group. Examples of the base include inorganic bases (for example, hydroxides, carbonates, phosphates, alkoxides or amides of alkali metals or alkaline earth metals) and organic bases. Specific inorganic bases include sodium hydroxide, potassium carbonate, sodium hexamethyldisilazide (NaHMDS), and potassium tert-butoxide. Specific organic bases include pyridine and triethylamine (NEt)3) Diazabicyclo [5.4.0]Undecene (DBU), diazabicyclo [5.4.0]Nonene (DBN) and diisopropylethylamine. A particular base is DBU in Tetrahydrofuran (THF) or Dichloromethane (DCM).
The compound of formula IV can be prepared by reacting N-hydroxy-cyanoimidoyl chloride (hydroxyheterocyclic chloride):
with an alkoxyethylene under suitable reaction conditions.
N-hydroxy-cyanoimidoyl chloride can be prepared by reacting N-hydroxy-2- (hydroxyimino) imidoacetyl chloride:
with dehydrating agents (e.g. thionyl chloride (SOCl)2) ) under suitable reaction conditions. Suitable reaction conditions include the presence of a solvent or solvent system, such as ethyl acetate (EtOAc), Dimethylformamide (DMF), EtOAc/DMF, acetonitrile (MeCN)/DMF, DCM/NEt3Methyl tert-butyl ether (MTBE)/NEt3，THF，THF/NEt3And THF/pyridine. A specific solvent is THF. A specific solvent system is THF/NEt3。
N-hydroxy-2- (hydroxyimino) imido acetyl chloride may be prepared by contacting chloral hydrate with hydroxylamine under conditions sufficient to provide N-hydroxy-2- (hydroxyimino) imido acetyl chloride. Examples of such conditions include the presence of a base and a solvent or solvent system (e.g., water, ethanol, isopropanol, or THF). Specific bases include inorganic bases (e.g., hydroxides, carbonates, phosphates, alkoxides, or amides of alkali and alkaline earth metals). A specific inorganic base is K2CO3，Na2CO3，NaOAc，KOAc，KHCO3And K3PO4.
A particular embodiment of the invention comprises the preparation of (1R, 2S, 3R) -1- (2- (iso-isomer)Process for oxazol-3-yl) -1H-imidazol-5-yl) butane-1, 2, 3, 4-tetraol:
the method comprises the following steps: will be different fromMixing oxazole-3-carbonitrile with a solvent and a first base to provide a first reaction mixture; mixing the first reaction mixture with fructosamine to provide a second reaction mixture; and separating (1R, 2S, 3R) -1- (2- (iso-iso) from the second reaction mixtureOxazol-3-yl) -1H-imidazol-5-yl) butane-1, 2, 3, 4-tetraol.
In particular methods, the second reaction mixture further comprises a second base. In a particular method, the solvent is methanol. In a particular method, the first base is the same as the second base. In a particular process, the first base is methoxide. In a particular process, the first base and the second base are both methoxide.
The invention comprises the preparation of (1R, 2S, 3R) -1- (2- (iso-iso)A process for the preparation of a crystalline form of oxazol-3-yl) -1H-imidazol-5-yl) butane-1, 2, 3, 4-tetraol. In one method, (1R, 2S, 3R) -1- (2- (iso-iso)Crystalline hydrates of oxazol-3-yl) -1H-imidazol-5-yl) butane-1, 2, 3, 4-tetraol are prepared by reacting a mixture comprising (1R, 2S, 3R) -1- (2- (iso-isomer)Oxazol-3-yl) -1H-imidazol-5-yl) butane-1, 2, 3, 4-tetraol and water and cooling and providing a precipitate, and isolating the precipitate. In one embodiment, the solution is at a temperature of from about 50 ℃ to about 100 ℃, from about 60 ℃ to about 90 ℃, or from about 70 ℃ to about 80 ℃ prior to cooling. In one embodiment, the solution is cooled to a temperature of less than about 25 ℃, 20 ℃, or 15 ℃. In a specific method, the separated precipitate is washed with water or an alcohol (e.g., ethanol).
In one method, (1R, 2S, 3R) -1- (2- (iso-iso)Anhydrous crystals of oxazol-3-yl) -1H-imidazol-5-yl) butane-1, 2, 3, 4-tetraol are prepared by reacting a mixture comprising (1R, 2S, 3R) -1- (2- (iso-isomer)Oxazol-3-yl) -1H-imidazol-5-yl) butane-1, 2, 3, 4-tetraol and an alcohol (e.g., ethanol) is cooled to provide a precipitate, and the precipitate is isolated. In one embodiment, the solution is at a temperature of about 65 ℃ to about 80 ℃, about 70 ℃ to about 80 ℃, or about 75 ℃ to about 80 ℃ prior to cooling. In one embodiment, the solution is cooled to a temperature of less than about 25 ℃, 20 ℃, or 15 ℃. In a particular methodThe separated precipitate is washed with an alcohol (e.g., ethanol).
Examples
Various aspects of the invention can be understood from the following examples.
Preparation of (1Z, 2E) -N-hydroxy-2- (hydroxyimino) -imidoacetyl chloride
A50L three-necked flask, equipped with a thermometer control, mechanical stirrer and dropping funnel, which was dried and blanketed with nitrogen, was charged with 6060g (2.4X) water and 3151g (1.26X) hydroxylamine hydrochloride. The reaction mixture was stirred at 20-25 ℃ for 10-30 minutes until the solid dissolved. A clear solution of 3134g (1.25X) potassium carbonate and 28000g (11.2X) water is added dropwise to the solution at 20-25 ℃ over 30-50 minutes, followed by addition of 2500g (1.0X) chloral hydrate in portions at 20-28 ℃. After addition, the reaction mixture was stirred at 25-30 ℃ for 4-5 hours and confirmed to be complete by HPLC. The reaction mixture was cooled to 0-5 deg.C and 9673g (3.87X) of 25% sodium hydroxide was added dropwise at 0-5 deg.C over 60-90 minutes. After addition, the stirred mixture was acidified with 12200g (4.89X) of 25% sulfuric acid at 0-5 ℃ until pH 3.0-3.5. The resulting mixture was extracted twice with 2775g (1.11X) methyl tert-butyl ether. The combined organic layers were dried over 1000g (0.4X) sodium sulfate, filtered, and then concentrated under reduced pressure to 1500g (0.6X) volume, diluted with 2670g (1.08X) n-heptane, and concentrated again to 1500g (0.6X) volume. The resulting slurry was charged with 2670g (1.08X) of n-heptane and then cooled to 0-5 ℃ and held at that temperature for 1 hour. After filtration, the wet cake was washed twice with 250g (0.1X) of n-heptane. The wet cake was dried under vacuum at 30-38 ℃ for 48 hours to give 737.0g of an off-white solid (content of the title compound: 98.3%, purity: 99.2%, yield 40%).1H NMR(DMSO-d6，400MHz)δ12.44(s，1H)，12.23(s，1H)，8.27(s，1H)；13C NMR(DMSO-d6100MHz) δ 143.19, 137.83; elemental analysis: c2H3N2O2Found value of Cl: c, 19.54; n, 22.30; h, 2.64. calcd: c, 19.61; n, 22.87; h, 2.47.
Preparation of 5-ethoxy-4, 5-dihydroisoAzole-3-carbonitrile
A dry, nitrogen-blanketed, 10-L three-necked flask equipped with thermometer control, mechanical stirrer and dropping funnel was charged with 6966.7g (7.3X) tetrahydrofuran and 950.0g (1.0X) of the compound (1Z, 2E) -N-hydroxy-2- (hydroxyimino) imidoacetyl chloride. The reaction mixture was cooled to 0-5 ℃ and 1845.2g (1.9X) of thionyl chloride was added dropwise over 60-90 minutes at 0-5 ℃. After addition, the reaction mixture was stirred at 10-15 ℃ for 6-7 hours and confirmed to be complete by HPLC. The reaction mixture was then concentrated in vacuo at 15-20 ℃ to about 1.0L (1.0X), then a total of 950g (0.9X) tetrahydrofuran was added and the residual thionyl chloride was distilled off. The resulting mixture was added dropwise to a solution of 2755g (2.9X) ethoxyethylene, 6764g (7.12X) tetrahydrofuran and 715.0g (0.75X) sodium carbonate in 3200.0g (3.4X) water at 0-5 deg.C over 30-40 minutes. After addition, the reaction mixture was stirred at 0-5 ℃ for 1-2 hours and confirmed to be complete by HPLC. The resulting mixture was separated and the aqueous layer was extracted with 1900g (2.0X) of methyl t-butyl ether, and then the combined organic layers were dried over 380g (0.4X) of sodium sulfate, filtered, and then concentrated to obtain 549.7g of a yellow oil (content of the title compound: 60.3%, purity: 97.0%, yield 30.5%).1H NMR(CDCl3，400MHz)δ5.76(dd，J＝2.0Hz，4.8Hz，1H)，3.86～3.90(m，1H)，3.60～3.65(m，1H)，3.21(dd，J＝6.8Hz，11.2Hz，1H)，3.00(dd，J＝2.0Hz，16Hz，1H)，1.21(T，J＝6.8Hz，1H)。
Preparation of isoAzole-3-carbonitrile
To a dry, nitrogen-blanketed, 10L three-necked flask equipped with thermometer control, mechanical stirrer, and dropping funnel was charged 52000g (18.6X) methylene chloride and 289.8g 5-ethoxy-4, 5-dihydroisoOxazole-3-carbonitrile (1.0X, 449.3g, content of this compound 64.5% by weight, true amount 289.8 g). The reaction mixture was cooled to 0-5 ℃ and then 173.8g (0.6X) diazabicyclo [5.4.0 ] was added dropwise over 20-30 minutes at 0-5 ℃]Undecene. After addition, the reaction mixture was stirred at 0-5 ℃ for 2-3 hours and confirmed to be complete by HPLC. The stirred mixture was neutralized to pH 6.5-7.0 with 1000.0g (3.45X) of 0.1N hydrogen chloride at 0-5 ℃. The resulting mixture was extracted twice with 1170g (4.0X) methyl tert-butyl ether. After separation, the combined organic layers were dried over 116g (0.4X) sodium sulfate, filtered, and then concentrated in vacuo to give crude isoOxazole-3-carbonitrile (544.6g, content of the title compound 21.99% by weight, actual amount 119.8g, 62% yield). Subsequent distillation (40 ℃ C./5 mmHg) gave 97.3g of a colorless oil (purity 99%, yield 50%).1H NMR(CDCl3，400MHz)δ8.64(d，J＝1.6Hz，1H)，6.70(d，J＝1.6Hz，1H)；13C NMR(CDCl3100MHz) delta 160.92, 139.19, 109.95, 107.40; elemental analysis: c4H2N2Measured value of O: c, 50.02; n, 27.74, H2.18. Calculated C, 51.07; n, 29.78; 2.14.
preparation of (1R, 2S, 3R) -1- (2- (iso-iso)Oxazol-3-yl) -1H-imidazol-4-yl) butane-1, 2, 3, 4-tetraol
Into a dried, nitrogen blanketed, 101 three-necked flask equipped with a thermometer control, mechanical stirrer and dropping funnel was charged 336.2g (1.0X) of isoOxazole-3-carbonitrile and 4125.0g (12.3X) methanol. To the stirred solution was added 449.2g (1.34X) of sodium methoxide (25-30 wt%) in methanol over 15 minutes. The mixture was stirred at 20-25 ℃ overnight. The above solution was transferred over 15 minutes to a slurry of 880.68g (2.62X) fructosamine acetate in 4125g (12.3X) methanol and the mixture was stirred at 20-25 ℃ for 6 hours. An additional 400.0g (1.2X) of sodium methoxide (25-30 wt%) in methanol was then added to the mixture over 10 minutes and the mixture was stirred for an additional 6 hours and confirmed to be complete by HPLC. The reaction mixture was then diluted with 3362.3g (10.0X) of water and concentrated under reduced pressure to remove methanol, filtered, and the filter cake was washed twice with 243.2g (0.7X) of water to give 1140g of an off-white solid (99.0% pure, 60% assay).
(1R, 2S, 3R) -1- (2- (iso-iso)Crystal of oxazol-3-yl) -1H-imidazol-4-yl) butane-1, 2, 3, 4-tetraol hydrate
5g of (1R, 2S, 3R) -1- (2- (iso-iso)Disalt of oxazol-3-yl) -1H-imidazol-4-yl) butane-1, 2, 3, 4-tetraolThe acid salt was dissolved in 50mL of water to provide a clear solution. To this solution was added 1M sodium hydroxide until the pH reached about 10 and a solid precipitated out. The solid was filtered and collected to obtain 5 to 6g of (1R, 2S, 3R) -1- (2- (iso-isomer)Oxazol-3-yl) -1H-imidazol-4-yl) butane-1, 2, 3, 4-tetraol free base.
To the wet cake obtained above, 50mL of water (10X) was added, and the resulting mixture was heated to 70-75 ℃ to provide a clear tan solution. On cooling, the solid began to crystallize out of solution. Further cooling causes more solid to crystallize until stirring becomes difficult. At this point, the solid was filtered, collected (2.36g of free base) and dried under vacuum at 50 ℃ overnight. Upon further cooling of the filtrate, a second crop of crystals was obtained.
Anhydrous (1R, 2S, 3R) -1- (2- (iso-iso)Crystal of oxazol-3-yl) -1H-imidazol-4-yl) butane-1, 2, 3, 4-tetraol
Mixing (1R, 2S, 3R) -1- (2- (iso-iso)Oxazol-3-yl) -1H-imidazol-4-yl) butane-1, 2, 3, 4-tetraol hydrate (726g) was heated in 7200.0g (10.0X) ethanol at 75-80 ℃ for 3-3.5 hours, then slowly cooled to 10-15 ℃ and stirred at 10-15 ℃ for 2-2.5 hours. The solid was filtered, washed with 726g (1.0X) ethanol and dried under vacuum at 30-40 deg.C for 20 hours to give 663g of anhydrous (1R, 2S, 3R) -1- (2- (iso-propyl) -acetateOxazol-3-yl) -1H-imidazol-4-yl) butane-1, 2, 3, 4-tetraol as an off-white solid.1H NMR(DMSO-d6Adding one drop of DC1, 400MHz) delta 8.71(t, J is 0.8Hz, 1H), 7.40(s, 1H), 6.89(t, J is 0.8Hz, 1H), 5.06(d, J is 1.2Hz, 1H), 3.53-3.69(m, 3H),3.49-3.52(m，1H)；13C NMR(DMSO-d6adding one drop of DC1, 100MHz) delta 163.2, 149.6, 139.0, 133.0, 118.5, 104.8, 73.4, 71.4, 65.2, 63.8; elemental analysis: c10H13N3O5Measured value: c, 44.50; n, 15.77; h, 5.39. Calculated values: c, 47.06; n, 16.46; h, 5.13.
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