CN110885304B

CN110885304B - A kind of preparation method of deuterated calcitriol and intermediate thereof

Info

Publication number: CN110885304B
Application number: CN201811045167.4A
Authority: CN
Inventors: 张庆文; 齐丽春; 张德杰
Original assignee: Shanghai Institute of Pharmaceutical Industry; China State Institute of Pharmaceutical Industry
Current assignee: China Pharmaceutical Industry Research Institute Co Ltd; Shanghai Pharmaceutical Industry Research Institute Co ltd
Priority date: 2018-09-07
Filing date: 2018-09-07
Publication date: 2022-04-05
Anticipated expiration: 2038-09-07
Also published as: CN110885304A

Abstract

本发明公开了一种氘代骨化三醇的制备方法、及其中间体。本发明提供了一种如式DG‑1所示的氘代骨化三醇的制备方法，其包括如下步骤：步骤(1)、在有机溶剂1中，在脱保护剂作用下，将如式II所示的化合物进行如下所示的脱羟基保护基反应，得到如式DG‑4所示的化合物即可；步骤(2)、在有机溶剂2中，在光照射和光敏剂存在下，将步骤(1)中所述的如式DG‑4所示的化合物进行如下所示的光异构化反应，得到所述的如式DG‑1所示的氘代骨化三醇即可；其中，R₁为羟基保护基。采用本发明的中间体的氘代骨化三醇制备方法，起始原料易得、合成路线短、操作简便、收率高。

The invention discloses a preparation method of deuterated calcitriol and an intermediate thereof. The invention provides a preparation method of deuterated calcitriol as shown in formula DG-1, which comprises the following steps: step (1), in organic solvent 1, under the action of a deprotecting agent, the The compound shown in II is subjected to the dehydroxylation protecting group reaction shown below to obtain the compound shown in formula DG-4; step (2), in organic solvent 2, in the presence of light irradiation and a photosensitizer, the The compound shown in the formula DG-4 described in the step (1) carries out the photoisomerization reaction shown below to obtain the deuterated calcitriol shown in the formula DG-1; wherein , R ₁ is a hydroxyl protecting group. The method for preparing the intermediate deuterated calcitriol of the present invention has the advantages of easy-to-obtain starting materials, short synthetic route, simple operation and high yield.

Description

Preparation method of deuterated calcitriol and intermediate thereof

Technical Field

The invention relates to a preparation method of deuterated calcitriol and an intermediate thereof.

Background

Calcitriol (calceriol) is a vitamin D drug and is clinically used for treating diseases such as osteoporosis and secondary hyperparathyroidism. 26,26,26,27,27, 27-hexadeutero-1 alpha, 25-dihydroxy vitamin D₃Is a calcitriol labeled with deuterium as a stable isotope, CAS registry number 78782-99-7, other names including(1 α,3 β,5Z,7E) -9, 10-ring-opened cholesta-5, 7,10(19) -triene-26, 26,26,27,27, 27-hexadeutero-1, 3, 25-triol, Ro 21-5535/2, and the like, hereinafter referred to as deuterated calcitriol. The chemical structural formula is shown as a formula DG-1.

The vitamin D compound labeled by the stable heavy isotope deuterium can be used for measuring the vitamin D compound in biological samples such as blood, tissues and the like. In particular, deuterated vitamin D compounds can be used as internal standards for mass spectrometry and LC-MS. For example, Yuan C et al (Rapid Communications in Mass Spectrometry,2011,25: 1241-1249) report quantitative determination of 1 α, 25-dihydroxyvitamin D in serum by liquid phase/tandem Mass Spectrometry (LC/MS/MS) using deuterated calcitriol as an internal standard₃(calcitriol).

Sestelo JP et al (Journal of Organic Chemistry,1993,58: 118-. Oxidation of iodo-alcohol 2 with Pyridine Dichromate (PDC) gave iodo-ketone 3 in 90% yield. Treatment of 3 with Lithium Diisopropylamide (LDA) at-78 deg.C, and subjecting the resulting enol to N-phenyl-bis (trifluoromethanesulfonimide) (Tf) at-78 deg.C₂NPh) to obtain the trifluoromethanesulfonate 4 with the yield of 92 percent. 4. The mixture of zinc, cuprous iodide and methyl acrylate was subjected to ultrasonic reaction in ethanol/water (7:3) at room temperature to give 5% yield of 65%. 5 and eneyne 6 protected by silyl ether are coupled by palladium catalysis to obtain dienyne 7 with the yield of 86 percent. Partial hydrogenation of 7 in the presence of quinoline poisoned Lindlar catalyst gave vitamin precursor 8 in 95% yield. 8 is refluxed in isooctane for 4h to obtain 9 with a yield of 96 percent. 9 and deuterated methyl magnesium iodide to carry out Grignard reaction, and then removing a silyl ether protecting group by tetrabutylammonium fluoride (TBAF) to obtain deuterated calcitriol (DG-1) with the two-step yield of 72 percent. See scheme 1 in the deuterated calcitriol literature, below.

Literature synthetic route 1 of deuterated calcitriol

The defects are as follows: the initial raw materials Inhoffen-Lythgoe diol 1 and the silyl ether protected eneyne 6 need to be prepared additionally, and the synthetic route is long; the use of ultrasonic reaction requires special equipment; ultra-low temperature reaction is used; using special reagents; partial hydrogenation catalyzed by Lindlar catalyst has difficulty in grasping the reaction end point and is liable to cause excessive hydrogenation.

De Luca HF et al (US 4269777) report that benzoyl protected high-cholenic acid ester 10 is used as a starting material, 7-position double bond is introduced through multi-step reaction, and then 3-position hydroxybenzoyl protection is removed to obtain an intermediate 11. 11, irradiating the mixture in 20 percent ethanol/benzene by ultraviolet light, and separating and purifying the mixture by High Performance Liquid Chromatography (HPLC) to obtain previtamin ester with the yield of 18 percent; the obtained previtamin ester is heated and rearranged in ethanol to obtain an intermediate 12. 12 reacts with p-toluenesulfonyl chloride in pyridine to form ester, and then reacts in methanol/dichloromethane at 55 ℃ in the presence of sodium bicarbonate to obtain an intermediate 13. 13 in the presence of selenium dioxide and tert-butyl peroxide, 1 alpha-hydroxyl is introduced to obtain an intermediate 14, and more 1-keto byproducts are generated at the same time, and the intermediate needs to be purified by preparative thin-layer chromatography. 14 is reacted with acetic anhydride in pyridine to give an ester, intermediate 15. 15 at 55 deg.c with formic acid, reacting the obtained 3-formic ester with sodium bicarbonate, preparing intermediate 16 and corresponding 5, 6-trans isomer by-product by preparative thin layer chromatography, and purifying by normal phase HPLC to obtain 16. 16 reacts with potassium hydroxide methanol solution in ether to remove acetyl at the 3-position, and an intermediate 17 is obtained. And (17) reacting with deuterated methyl magnesium halide or deuterated methyl lithium to obtain deuterated calcitriol (DG-1). See scheme 2 in the deuterated calcitriol literature, below.

Literature synthetic route 2 of deuterated calcitriol

The defects are as follows: the starting materials are expensive and not easy to obtain, the synthetic route is long, the operation is complicated, the multi-step reaction products need to be subjected to preparative thin layer chromatography or preparative normal phase HPLC separation and purification, and the multi-step reaction yield is less than 20% (for example, the intermediate 12 is prepared from the intermediate 11 through photoreaction ring opening and thermal rearrangement).

De Luca HF et al (US patent US4269777) also reported that oxidation of methyl ester of homolithocholic acid 18 as starting material with 2, 3-dichloro-5, 6-dicyano-1, 4-benzoquinone (DDQ) gave intermediate 19. The corresponding acid is obtained by saponification of 19 with aqueous potassium hydroxide solution, and then the 1 alpha, 2 alpha-epoxide intermediate 20 is obtained by epoxidation under the action of 10% sodium hydroxide and 30% hydrogen peroxide. 20 is reduced by metal sodium (20 times excess) and liquid ammonia at the temperature of minus 33 ℃, and then is converted into methyl ester by diazomethane in aether, thus obtaining an intermediate 21. 21 was acetylated at 60 ℃ in acetic anhydride/pyridine (1:1) to give intermediate 22. 22 reacts with sodium bicarbonate and 1, 3-dibromo-5, 5-dimethylhydantoin at 75 ℃, then reflows with collidine in xylene, and then reacts with p-toluenesulfonic acid at 70 ℃ in dioxane to obtain an intermediate 23. Irradiating with ultraviolet light at 0 deg.C in 20% ethanol/benzene, performing thermal rearrangement in ethanol, saponifying with potassium hydroxide, and separating and purifying by normal phase HPLC to obtain intermediate 17. And (17) reacting with deuterated methyl magnesium halide or deuterated methyl lithium to obtain deuterated calcitriol (DG-1). See scheme 3 in the deuterated calcitriol literature, below.

Literature synthetic route 3 of deuterated calcitriol

The defects are as follows: the starting materials are expensive and not easy to obtain, the synthetic route is long, harsh reaction conditions and special reagents are used, and the preparation of the key intermediate 17 by normal phase HPLC separation and purification is required.

Disclosure of Invention

The invention aims to solve the technical problem of overcoming the defects of expensive and not easily available starting materials, harsh reaction conditions, special reagents, complex separation and purification and the like of the conventional preparation method of the deuterated calcitriol, and provides a preparation method of the deuterated calcitriol and an intermediate thereof. The preparation method of the intermediate deuterated calcitriol has the advantages of easily obtained starting materials, simple and convenient operation and high yield.

The present invention solves the above-mentioned problems by the following technical means.

The invention provides a preparation method of deuterated calcitriol shown as a formula DG-1, which comprises the following steps:

step (1), carrying out a dehydroxylation protecting group reaction on a compound shown as a formula II in an organic solvent 1 under the action of a deprotection agent to obtain a compound shown as a formula DG-4;

step (2), in an organic solvent 2, under the conditions of light irradiation and the existence of a photosensitizer, carrying out photoisomerization reaction on the compound shown as the formula DG-4 in the step (1) as shown in the specification to obtain deuterated calcitriol shown as the formula DG-1;

wherein R is₁Is a hydroxyl protecting group.

Preferably, R is₁Each independently is

R₃、R₄And R₅Each independently is C₁～C₆Alkyl or phenyl.

Said R₁In (b), the C₁-C₆Each alkyl group is independently a methyl, ethyl, propyl, butyl, pentyl or hexyl group, for example a methyl or tert-butyl group.

In one embodiment of the present invention, R₁Is tert-butyldimethylsilyl (tBuMe)₂Si-, TBS/TBDMS), Trimethylsilyl (TMS), Triethylsilyl (TES), Diphenylmethylsilyl (DPMS), Triisopropylsilyl (TIPS) or tert-butyldiphenylsilyl (TBDPS); preferably tert-butyldimethylsilyl (tBuMe)₂Si-，TBS/TBDMS)。

In step (1), the operation and conditions for the dehydroxylation protecting group reaction may be those conventional in the art. For example, see "Protective Groups in Organic Synthesis", 3 rd edition, ed. T.W.Greene & P.G.M.Wuts, John Wiley 1999.

The organic solvent 1 in the present invention is preferably an ethereal solvent (e.g., tetrahydrofuran) and/or an alcoholic solvent (e.g., methanol and/or ethanol).

The amount of the organic solvent 1 used in the present invention is not limited, and the reaction is not affected.

The deprotecting agent described in the invention can be a deprotecting agent conventional in the art for such reactions, e.g., when R is₁Is composed of

When the deprotection agent is fluorine-containing deprotection agent and/or hydrogen chloride solution; the fluorine-containing deprotection agents include, but are not limited to, tetrabutylammonium fluoride (TBAF); the hydrogen chloride solution includes, but is not limited to, an ethanol solution of hydrogen chloride.

The molar ratio of the deprotection agent to the compound represented by the formula II is preferably 6:1 to 18:1 (for example, 13: 1).

The dehydroxylation protecting group reaction is preferably carried out in an inert gas atmosphere, such as an argon atmosphere.

The temperature for the dehydroxylation protecting group reaction is preferably room temperature (e.g., 15 ℃ C. to 30 ℃ C.).

In the reaction for removing the hydroxyl protecting group, the progress of the reaction can be monitored by a conventional monitoring method in the art (such as TLC, HPLC or NMR), and the end point of the reaction is generally the disappearance or no longer reaction of the compound represented by the formula II.

The preparation method preferably further comprises the following post-treatment steps: and (2) after the reaction in the step (1) is finished, concentrating, extracting, concentrating and carrying out column chromatography. The concentration and column chromatography can be performed according to the conventional operation in the field, for example, the concentration is preferably performed by reduced pressure distillation; in the column chromatography, ethyl acetate/petroleum ether (volume ratio 50:50) is preferably used as a mobile phase and silica gel is preferably used as a stationary phase.

In step (2), the operations and conditions of the photoisomerization reaction may be those conventional in the art. For example:

the organic solvent 2 in the present invention is preferably an alcohol solvent (e.g., methanol and/or ethanol).

The amount of the organic solvent 2 used in the present invention is not limited, and the reaction is not affected.

The photosensitizer described in the present invention can be a triplet photosensitizer, preferably anthracene and/or 9-acetyl anthracene, more preferably 9-acetyl anthracene.

The molar ratio of the photosensitizer to the compound represented by the formula DG-4 is preferably 0.5:1 to 0.05:1 (e.g., 0.1: 1).

The photoisomerization reaction is preferably performed in an inert gas atmosphere, such as an argon atmosphere.

The photoisomerization reaction temperature is preferably-15 deg.C to 15 deg.C (e.g., -5 deg.C to 0 deg.C).

The light irradiation is preferably a high-pressure mercury lamp or a medium-pressure mercury lamp, optionally using a suitable filter.

In the photoisomerization reaction, the progress of the reaction can be monitored by conventional monitoring methods in the art (e.g., TLC, HPLC or NMR), and is generally at the end of the reaction when the compound of formula DG-4 disappears or no longer reacts.

The preparation method preferably further comprises the following post-treatment steps: and (3) after the reaction in the step (2) is finished, concentrating, carrying out column chromatography, and crystallizing. The concentration and column chromatography can be performed according to the conventional operation in the field, for example, the concentration is preferably performed by reduced pressure distillation; in the column chromatography, ethyl acetate/petroleum ether (containing 60-90% of ethyl acetate by volume) is preferably adopted as a mobile phase for gradient elution, and silica gel is adopted as a stationary phase; the crystallization is preferably carried out using methyl formate as a solvent.

The deuterated calcitriol synthesized by the preparation method provided by the invention has high purity, such as HPLC purity of not less than 95%, preferably not less than 98%, and more preferably not less than 99%. Reference is made to calcitriol for the HPLC analysis method. For example, the prepared deuterated calcitriol can be subjected to HPLC purity examination by the method reported in the literature (Chenyang et al, J. Pharmacology, 2005,25(2): 140-141).

The preparation method of the deuterated calcitriol shown as the formula DG-1 can also comprise the following steps: in an organic solvent 3, a compound shown as a formula I and CD are mixed₃Carrying out Grignard reaction on MgX as shown in the specification to obtain the compound as shown in the formula II;

wherein R is₁As described above; r₂Is an alkyl group;

x is halogen.

Said R₂Preferably C₁-C₆Alkyl radicals, such as the methyl, ethyl, propyl, butyl, pentyl or hexyl radical, and also methyl or ethyl radicals, for example.

The X is preferably Cl, Br or I, more preferably I.

In the grignard reaction, the organic solvent 3 may be an organic solvent which is conventional in the reactions of this type in the art, and in the present invention, an ether solvent (tetrahydrofuran and/or diethyl ether) is preferred.

The amount of the organic solvent 3 used in the present invention is not limited, and the reaction is not affected.

In the Grignard reaction, the CD₃The molar ratio of MgX to the compound shown in the formula I can be 15: 1-2: 1, preferably 9: 1-2.5: 1; more preferably 9:1 to 4: 1. For example, the molar ratio of the deuterated methyl magnesium iodide to the compound represented by the formula I can be 15:1 to 2:1, preferably 9:1 to 2.5:1, and more preferably 9:1 to 4: 1.

The CD₃MgX may be either commercially available or prepared in situ. For example, from CD₃Preparing X and metal magnesium on site; also for example, from deuterated iodomethanePreparing deuterated methyl magnesium iodide on site with metal magnesium; for another example, the deuterated methyl magnesium iodide is prepared in situ from deuterated methyl iodide and magnesium metal, and the molar ratio of the deuterated methyl iodide to the magnesium metal can be 1: 1.5-1: 1.05(1: 1.25). The CD₃MgX and CD₃X each have a high deuterium isotopic purity, e.g., 99% deuterium isotopic purity.

The temperature of the grignard reaction may be a temperature conventional in such reactions in the art, and in the present invention is preferably-10 ℃ to 15 ℃ (e.g., 0 ℃ to 5 ℃).

In the grignard reaction, the progress of the reaction can be monitored by conventional monitoring methods in the art (e.g., TLC, HPLC, or NMR), and is generally terminated when the compound represented by formula I disappears or no longer reacts.

The preparation method preferably further comprises the following post-treatment steps: and after the Grignard reaction is finished, quenching, extracting and concentrating to obtain the product. The quenching, extraction and concentration can be performed according to the conventional operation in the field, for example, the quenching is preferably performed by saturated ammonium chloride aqueous solution; in the extraction, ethyl acetate is preferably adopted for extraction; the concentration is preferably carried out under reduced pressure.

The preparation method preferably further comprises the following steps: after the Grignard reaction is finished, the compound shown as the formula II is directly used in the step (1) without purification.

The compounds of formula I are commercially available or can be prepared according to literature reported methods. For example, the compound of formula I is (1 α,3 β,5E,7E) -1, 3-bis [ [ (1, 1-dimethylethyl) dimethylsilyl]Oxygen gas]-9, 10-Cyclocholane-5, 7,10(19) -triene-24-carboxylic acid ethyl ester (DG-2) (R)₁＝TBS，R₂Et), it can be prepared according to the literature (Man chand PS Et al, Journal of Organic Chemistry,1995,60(20): 6574-; buxade Vinas A et al, Spanish patent ES2472241B 1).

One synthetic route for DG-2 is shown below:

with vitamin D₂The intermediate 24 is prepared by carrying out Diels-Alder reaction on the starting raw material and sulfur dioxide and then reacting the starting raw material and tert-butyldimethylsilyl chloride (TBSCl) to protect hydroxyl, wherein the yield is 97%; 24, ozonizing in a mixed solvent of dichloromethane and methanol at the temperature of-10 ℃, and reducing the obtained ozonide by sodium borohydride to obtain an intermediate 25 with the yield of 87%; conversion of 25 to iodide 26 using iodine/triphenylphosphine/imidazole, yield 71%; heating ethyl acrylate, nickel chloride hexahydrate and zinc powder in pyridine to prepare a zero-valent nickel complex on site, and performing conjugate addition on the zero-valent nickel complex and 26 to obtain an intermediate 27; 27 in ethanol containing sodium bicarbonate, the mixture is heated to generate a reverse Diels-Alder reaction to release sulfur dioxide, thus obtaining an intermediate 28 with a yield of 73 percent in two steps. 28 hydroxylating the C1 site with selenium dioxide and N-methylmorpholine N-oxide (NMO) under the reflux of dichloromethane/methanol, protecting the C1 site hydroxyl with tert-butyldimethylsilyl chloride, and carrying out chromatographic separation to obtain a compound DG-2 with the yield of 41%. With vitamin D₂The total yield is about 18%.

The invention provides a compound shown as a formula II:

wherein R is₁As described above.

In one embodiment of the present invention, the compound represented by formula II has the following structure:

the invention provides a compound shown as a formula DG-4:

the invention provides a preparation method of a compound shown as a formula II, which comprises the following steps: in an organic solvent 3, a compound shown as a formula I and CD are mixed₃Carrying out Grignard reaction on MgX as shown in the specification to obtain the compound as shown in the formula II; the CD₃The molar ratio of MgX to the compound shown in the formula I is 15: 1-4: 1;

wherein R is₁And R₂As described above;

x is halogen.

The X is preferably Cl, Br or I, more preferably I.

In the grignard reaction, the organic solvent 3 may be an organic solvent which is conventional in the reactions of this type in the art, and in the present invention, an ether solvent (e.g., tetrahydrofuran and/or diethyl ether) is preferred.

In the Grignard reaction, the CD₃The molar ratio of MgX to the compound shown in the formula I is preferably 9: 1-4: 1.

The CD₃MgX may be either commercially available or prepared in situ. For example, from CD₃Preparing X and metal magnesium on site; as another example, deuterated methyl magnesium iodide is prepared in situ from deuterated methyl iodide and magnesium metal; for another example, the deuterated methyl magnesium iodide is prepared in situ from deuterated methyl iodide and magnesium metal, and the molar ratio of the deuterated methyl iodide to the magnesium metal can be 1: 1.5-1: 1.05(1: 1.25). The CD₃MgX and CD₃X each have a high deuterium isotopic purity, e.g., 99% deuterium isotopic purity.

The preparation method of the deuterated calcitriol (DG-1) is the first synthetic route for preparing the deuterated calcitriol. On the basis, the invention further provides the following two synthetic routes for preparing the deuterated calcitriol (DG-1).

Specifically, the second synthetic route for preparing deuterated calcitriol of the invention can be as follows: taking I as a starting material, and carrying out photoisomerization reaction in the presence of a photosensitizer to obtain an intermediate III; III and a deuterated methyl Grignard reagent are subjected to a Grignard reaction to obtain an intermediate IV; and IV, removing a hydroxyl protecting group to obtain deuterated calcitriol (DG-1).

The third synthetic route for preparing deuterated calcitriol can be as follows: taking the I as an initial raw material, and carrying out a Grignard reaction with a deuterated methyl Grignard reagent to obtain an intermediate II; II, carrying out photoisomerization reaction in the presence of a photosensitizer to obtain an intermediate IV; and IV, removing a hydroxyl protecting group to obtain deuterated calcitriol (DG-1).

In the present invention, said C₁-C₆Each alkyl is independently methyl, ethyl, propyl, butyl, pentyl or hexyl; wherein propyl is C₃Alkyl (including isomers such as n-propyl or isopropyl); butyl being C₄Alkyl (including isomers, e.g. n-butyl, sec-butyl, isobutyl or tert-butyl)(ii) a Pentyl is C₅Alkyl (including isomers such as n-pentyl, 1-methyl-butyl, 1-ethyl-propyl, 2-methyl-1-butyl, 3-methyl-1-butyl, isopentyl, tert-pentyl or neopentyl); hexyl is C₆Alkyl (including isomers such as n-hexyl or isohexyl).

The above preferred conditions can be arbitrarily combined to obtain preferred embodiments of the present invention without departing from the common general knowledge in the art.

The reagents and starting materials used in the present invention are commercially available.

The positive progress effects of the invention are as follows: the preparation method of the deuterated calcitriol has the advantages of easily available starting materials, short synthetic route, simple and convenient operation and high yield.

Detailed Description

The invention is further illustrated by the following examples, which are not intended to limit the scope of the invention. The experimental methods without specifying specific conditions in the following examples were selected according to the conventional methods and conditions, or according to the commercial instructions. The reagents and starting materials used in the present invention are commercially available or can be prepared according to known literature methods. The NMR was model number Varian INOVA-400; the mass spectrometer model was Micromass Q-Tof micro, electrospray ionization (ESI), positive ionization mode from Waters corporation. HPLC purity examination of the prepared deuterated calcitriol was performed according to the method reported in the reference literature (Chenyang Sheng et al, J. Med. Analyzer., 2005,25(2): 140-141).

In the following examples, room temperature means 15 ℃ to 30 ℃.

Example 1

Preparation of (1 alpha, 3 beta, 5E,7E) -26, 27-hexadeutero-1, 3-bis [ [ (1, 1-dimethylethyl) dimethylsilyl ] oxy ] -9, 10-ring-opened cholest-5, 7,10(19) -trien-25-ol (DG-3)

DG-2(3.2g,4.85mmol) was dissolved in anhydrous tetrahydrofuran (16ml) under an argon atmosphere, followed by dropwise addition of deuterated methyl magnesium iodide (CD) with cooling in an ice-water bath₃MgI) in 1.0mol/L diethyl ether (19.4ml,19.4 mmol). After dropping, the reaction mixture was warmed to room temperature and stirred for 3 h. The resulting reaction mixture was cooled to 0 ℃ and carefully treated with saturated ammonium chloride waterThe reaction was quenched with the solution. Adding ethyl acetate for extraction. The organic extract was washed with a saturated aqueous sodium chloride solution and dried over anhydrous sodium sulfate. Vacuum concentrating, and vacuum drying to obtain DG-3 (quantitative yield). The obtained DG-3 does not contain DG-2, does not need to be purified, and can be directly put into the next reaction.¹H NMR(400MHz，CDCl₃)δ:6.46(d，J＝11.5Hz，1H)，5.83(d，J＝11.5Hz,1H),4.99(m,1H),4.94(m,1H),4.54(m,1H),4.22(m,1H),0.94(d,J＝6.4Hz,3H),0.90(s,9H),0.87(s,9H),0.55(s,3H),0.07(d,J＝2.0Hz,6H),0.06(s,6H)。ESI-MS(m/z):651.37[M+H]⁺。

Example 2

Magnesium chips (1.33g,54.7mmol) were mixed with dehydrated ether (6ml), and a solution of deuterated iodomethane (6.33g,43.66mmol) in dehydrated ether (26ml) was added dropwise under an argon atmosphere at 0 to 5 ℃. After dripping, reflux reaction is carried out for 30min, and deuterated methyl magnesium iodide (CD) is prepared on site₃MgI). Then, a solution of DG-2(3.2g,4.85mmol) in anhydrous tetrahydrofuran (16ml) was added dropwise to the reaction mixture at 0 to 5 ℃. Stirring at 0 deg.C for 30min, and stirring at room temperature for 1 h. The reaction was quenched with cooling by careful addition of saturated aqueous ammonium chloride. Adding ethyl acetate for extraction. The organic extract was washed with a saturated aqueous sodium chloride solution and dried over anhydrous sodium sulfate. Vacuum concentrating, and vacuum drying to obtain DG-3 (quantitative yield). The obtained DG-3 does not contain DG-2, does not need to be purified, and can be directly put into the next reaction.

Example 3

Preparation of (1 alpha, 3 beta, 5E,7E) -9, 10-Ring-opened cholest-5, 7,10(19) -triene-1, 3, 25-triol (DG-4)

DG-3 (4.85 mmol in quantitative yield) obtained in example 2 was dissolved in anhydrous tetrahydrofuran (36ml) under an argon atmosphere, and a 1.0mol/L tetrahydrofuran solution (64ml, 64mmol) of tetrabutylammonium fluoride (TBAF) was added, followed by stirring at room temperature for 8 hours. The resulting reaction mixture was concentrated under reduced pressure, and ethyl acetate was added to the residue to extract. The organic extract was washed with half-saturated aqueous sodium chloride solution and dried over anhydrous sodium sulfate. Concentrating under reduced pressure to obtain solid residue. The crude product is processed by rapidPurification by silica gel preparative chromatography (elution with ethyl acetate/petroleum ether (50: 50 by volume)) afforded DG-4 as a white solid (1.64g, 80% yield).¹H NMR(400MHz,CDCl₃)δ:6.58(d,J＝11.5Hz,1H),5.89(d,J＝11.5Hz,1H),5.13(d,J＝1.4Hz,1H),4.97(s,1H),4.50(m,1H),4.24(m,1H),2.88(m,1H),2.85(m,1H),0.95(d,J＝6.4Hz,3H),0.57(s,3H)。ESI-MS(m/z):445.49[M+Na]⁺。

Example 4

Preparation of deuterated calcitriol (DG-1)

A solution of DG-4(0.35g,0.8mmol) and 9-acetylanthracene (0.018g,0.08mmol) in methanol (250mL) was added to the photoreactor and irradiated with a high pressure mercury lamp under argon at-5 ℃ to 0 ℃ until the reaction was complete. The obtained reaction solution was transferred to an eggplant-shaped bottle and concentrated under reduced pressure. The residue was purified by flash silica gel preparative chromatography (gradient elution with ethyl acetate/petroleum ether (60-90% by volume) followed by recrystallization from methyl formate to give DG-1 as a white solid (0.21g, 60% yield). HPLC purity 99.14%.¹H NMR(400MHz,(CD₃)₂CO)δ:6.29(d,J＝11.2Hz,1H),6.09(d,J＝11.2Hz,1H),5.31(m,1H),4.87(m,1H),4.39(m,1H),4.16(m,1H),3.86(d,J＝4.7Hz,1H),3.61(d,J＝4.1Hz,1H),3.05(s,1H),2.86(dd,J＝12.0,4.1Hz,1H),2.50(dd,J＝13.3,2.9Hz,1H),2.28(dd,J＝13.4,6.1Hz,1H),0.97(d,J＝6.4Hz,3H),0.58(s,3H)。ESI-MS(m/z):445.14[M+Na]⁺。

Comparative example 1

DG-2(3.2g,4.85mmol) was dissolved in anhydrous tetrahydrofuran (16ml) under an argon atmosphere, followed by dropwise addition of deuterated methyl magnesium iodide (CD) with cooling in an ice-water bath₃MgI) in 1.0mol/L diethyl ether (12.3ml,12.3 mmol). After dropping, the reaction mixture was stirred for 15min under cooling in an ice-water bath, then warmed to room temperature and stirred for 3 h. The resulting reaction mixture was cooled to 0 ℃ and carefully quenched with saturated aqueous ammonium chloride. Adding ethyl acetate for extraction. Washing the organic extract with saturated sodium chloride aqueous solution, and drying with anhydrous sodium sulfate. Concentrating under reduced pressure, and vacuum drying. The residue obtained, which contains, in addition to DG-3, a relatively large amount (about 30%) of the starting DG-2 which has not reacted, needs to be purified before it can be fed to the next reaction.

Claims

1. a preparation method of deuterated calcitriol as shown in formula DG-1, is characterized in that, it comprises the steps:

Step (1), in organic solvent 1, under the action of a deprotecting agent, the compound shown in formula II is subjected to the dehydroxylation protecting group reaction shown below to obtain the compound shown in formula DG-4;

In step (2), in organic solvent 2, in the presence of light irradiation and photosensitizer, the compound represented by the formula DG-4 described in step (1) is subjected to the photoisomerization reaction shown below to obtain Described deuterated calcitriol as shown in formula DG-1 gets final product;

Wherein, R ₁ is a hydroxyl protecting group;

The preparation method further comprises the following steps: in the organic solvent 3, the compound shown in formula I is subjected to the Grignard reaction shown below with CD ₃ MgX to obtain the compound shown in the formula II, namely Can;

R ₂ is C ₁ -C ₆ alkyl; X is I;

The molar ratio of the CD ₃ MgX to the compound represented by formula I is 15:1 to 4:1.

2. preparation method as claimed in claim 1, is characterized in that, described R ₁ is

R ₃ , R ₄ and R ₅ are each independently C ₁ -C ₆ alkyl or phenyl;

And/or, described organic solvent 1 is ether solvent and/or alcohol solvent;

And/or, the deprotection agent is a fluorine-containing deprotection agent and/or a hydrogen chloride solution;

And/or, the molar ratio of the deprotecting agent to the compound shown in formula II is 6:1 to 18:1;

And/or, the described dehydroxylation protecting group reaction is carried out in an inert gas atmosphere;

And/or, the temperature of the dehydroxy protecting group reaction is 15°C to 30°C;

And/or, described organic solvent 2 is alcoholic solvent;

And/or, the photosensitizer is a triplet photosensitizer;

And/or, the molar ratio of the photosensitizer to the compound represented by the formula DG-4 is 0.5:1 to 0.05:1;

And/or, the described photoisomerization reaction is carried out in an inert gas atmosphere;

And/or, the temperature of the photoisomerization reaction is -15℃～15℃;

And/or, the light irradiation is high pressure mercury lamp or medium pressure mercury lamp irradiation.

3. The preparation method of claim 2, wherein in the R ₁ , the C ₁ -C ₆ alkyl groups are each independently methyl, ethyl, propyl, butyl, pentyl base or hexyl;

And/or, in described organic solvent 1, described ether solvent is tetrahydrofuran;

And/or, in described organic solvent 1, described alcoholic solvent is methanol and/or ethanol;

And/or, in described deprotection agent, described fluorine-containing deprotection agent is tetrabutylammonium fluoride;

And/or, in described deprotection agent, described hydrogen chloride solution is the ethanolic solution of hydrogen chloride;

And/or, the mol ratio of described deprotecting agent and described compound shown in formula II is 13:1;

And/or, in described organic solvent 2, described alcoholic solvent is methyl alcohol and/or ethanol;

And/or, in the photosensitizer, the triplet photosensitizer is anthracene and/or 9-acetyl anthracene;

And/or, the mol ratio of described photosensitizer and described compound shown as formula DG-4 is 0.1:1;

And/or, the temperature of the photoisomerization reaction is -5°C～0°C;

And/or, the preparation method further includes the following post-processing steps: after the reaction in the step (1) is completed, concentration, extraction, concentration and column chromatography are performed;

And/or, the preparation method further includes the following post-processing steps: after the reaction in the step (2) is completed, concentration, column chromatography, and crystallization are sufficient.

4. preparation method as claimed in claim 3 is characterized in that, described R ₁ is tert-butyldimethylsilyl, trimethylsilyl, triethylsilyl, diphenylmethyl silyl, triisopropylsilyl or tert-butyldiphenylsilyl.

5. preparation method as claimed in claim 1, is characterized in that, described organic solvent 3 is ether solvent;

And/or, the CD ₃ MgX is prepared on site by CD ₃ X and metal magnesium;

And/or, the temperature of the Grignard reaction is -10°C to 15°C.

6. The preparation method of claim ₅ , wherein the R is methyl, ethyl, propyl, butyl, pentyl or hexyl;

And/or, in described organic solvent 3, described ether solvent is tetrahydrofuran and/or ether;

And/or, the molar ratio of the CD ₃ MgX to the compound shown in formula I is 9:1 to 4:1;

And/or, the CD ₃ MgX is prepared on site by deuterated iodomethane and metallic magnesium, and the molar ratio of deuterated iodomethane and metallic magnesium is 1:1.5～1:1.05;

And/or, the temperature of the Grignard reaction is 0°C to 5°C;

And/or, the preparation method further includes the following post-processing steps: after the Grignard reaction is completed, quenching, extracting and concentrating are finished;

And/or, the preparation method further includes the following steps: after the Grignard reaction is completed, the compound represented by the formula II is directly used in the above step (1) without purification.

7. The preparation method of claim 6, wherein the R ₂ is methyl or ethyl.

8. a compound shown in formula II or a compound shown in formula DG-4:

wherein R ₁ is as described in any one of claims 1 to 4.

9. the compound shown in the formula II as claimed in claim 8 or the compound shown in the formula DG-4, is characterized in that, the described compound shown in the formula II is the following structure:

10. a preparation method of the compound shown in formula II, is characterized in that, it comprises the steps: in organic solvent 3, the compound shown in formula I and CD ₃ MgX are carried out Grignard reaction as shown below , to obtain the compound shown in formula II; the molar ratio of the CD ₃ MgX to the compound shown in formula I is 15:1 to 4:1; X is I;

wherein, R ₁ and R ₂ are as described in any one of claims 1 to 7;

The operation and conditions of the preparation method are as described in claim 6 or 7.