HK1169121A1 - A preparation method of phosphoric monoester compound of acyclic nucleoside antiviral drugs - Google Patents

Abstract

Provided is a method for preparing an acyclic nucleoside monophosphate compound as an antiviral drug, which comprises reacting an acyclic nucleoside antiviral drug such as adefovir or tenofovir as a raw material, with a aliphatic long-chain alkoxy-ethanol/propanol, to obtain a target compound. The present invention overcomes the disadvantage in the prior art, not only improves the quality of adefovir or tenofovir monophosphate, but also reduces the production cost, and meanwhile has the advantages of being convenient in operation and being easy for industrial production.

Description

Preparation method of phosphate monoester compound of acyclic nucleoside antiviral drug

Technical Field

The invention belongs to the technical field of medicines, and particularly relates to a preparation method of a phosphoric monoester compound of an acyclic nucleoside antiviral medicine, in particular to a preparation method of an adefovir or tenofovir monoester compound.

Background

In the treatment of viral infectious diseases, the problem of viral resistance is becoming more and more prominent. Compared with the cyclic nucleoside reverse transcriptase inhibitor, the acyclic nucleoside compounds adefovir and tenofovir have obvious advantages in preventing the problem of virus resistance, are effective to virus strains resistant to cyclic nucleoside drugs, have low drug resistance incidence rate and relatively low toxicity, and can be used for treating patients infected with HIV-1 and HBV simultaneously. However, the phosphate carries negative charges, the polarity is too strong, the biological membrane permeability is poor, and the bioavailability is low, so that the phosphate cannot be used as a medicine for clinical application. The diester prodrugs adefovir and tenofovir disopropioxymethyl ester fumarate improves the bioavailability of the drug and is approved by FDA to be on the market in 2001. As a prodrug, the prodrug has no antiviral activity, and can exert curative effect only after being dissociated out of original drugs after entering a body, and part of the drugs are hydrolyzed before being absorbed into blood; in addition, the released active compounds of adefovir and tenofovir are also quickly discharged out of the body due to the problem of poor membrane permeability, so that the concentration of the active compounds at the infected part is difficult to maintain, and the bioavailability of the active compounds in the human body is still only about 28%. Therefore, the adefovir and tenofovir have important value for further research and modification.

In the patent (CN1810816), a fat-soluble long-chain alkoxyethyl long chain is introduced to one hydroxyl of a phosphate group in a tenofovir molecule, so that one hydroxyl of the phosphate group in the molecular structure is esterified and the other hydroxyl is still in a free state, and the phosphoric acid long-chain alkoxyethyl/propyl monoester derivatives of adefovir and tenofovir are obtained. After long-chain alkoxyethyl/propyl is introduced into the compound, the pharmacokinetic property of the compound is improved, and the other free hydroxyl in the phosphate group can be phosphorylated to participate in the virus replication process and exert the antiviral effect, so that the antiviral activity of tenofovir is retained. Namely, the introduction of the fat-soluble long chain not only improves the pharmacokinetic property of the compound, but also retains the antiviral activity.

When the tenofovir monoester is synthesized, two-step reaction is needed in side chain synthesis, stirring reaction is needed for 6 hours at 80 ℃ in the reaction for synthesizing the tenofovir monoester, column chromatography separation is needed in post-treatment, and industrial production is not easy to realize.

Disclosure of Invention

The invention aims to provide a preparation method of a novel acyclic nucleoside antiviral drug phosphomonoester compound, in particular to adefovir and tenofovir monoester, which can simplify the operation steps, reduce the production cost and is suitable for industrial production.

In order to achieve the purpose, the invention adopts the following technical scheme:

the invention provides a preparation method of a phosphoric monoester compound of an acyclic nucleoside antiviral drug, which comprises the steps of firstly preparing a fatty side chain (long-chain alkoxy-ethanol/propanol), and then reacting with the acyclic nucleoside antiviral drug such as adefovir or tenofovir to obtain a target compound.

A preparation method of acyclic nucleoside antiviral drug monoester compound with the structure shown in the general formula I,

wherein R is CH₃Or H; m is 0-8, n is 1-20;

the method comprises the following specific steps:

1) dissolving substituted alkane and dihydric alcohol in aprotic solvent, adding alkali, reacting at room temperature for 10-16 hr to obtain compound II HOCH₂(CH₂)_mCH₂OCH₂(CH₂)_nCH₃The substituted alkane is C3-C23 alkane substituted by halogen, methane sulfonic acid group or p-toluene sulfonic acid group, and the dihydric alcohol is C2-C10 straight-chain alkane containing two hydroxyl groups;

2) dissolving the acyclic nucleoside antiviral drug, the compound II and triphenylphosphine in an aprotic solvent, adding a dehydration reagent for three times, and stirring at room temperature to react to obtain the compound I.

Wherein the substituted alkane is preferably a long-chain alkane of C12-C18 substituted by bromine.

The diol is preferably ethylene glycol or 1, 3-propanediol.

The aprotic solvent is selected from benzene, diethyl ether, tetrahydrofuran, carbon tetrachloride, dimethyl sulfoxide, N-dimethylformamide, N-dimethylacetamide, acetone, acetonitrile, hexamethylphosphoramide, pyridine or pyrrole, and is preferably selected from dimethyl sulfoxide, N-dimethylformamide or tetrahydrofuran.

The alkali is selected from sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium carbonate or potassium carbonate, and is preferably sodium hydroxide or potassium hydroxide.

The acyclic nucleoside antiviral drug is Adefovir (Adefovir, PMEA) or Tenofovir (Tenofovir, PMPA), and is commercially available.

The dehydrating agent is diisopropyl azodicarboxylate (DIAD) or diethyl azodicarboxylate (DEAD), and the molar ratio of the dehydrating agent to the acyclic nucleoside antiviral drug is 1-5:1, preferably 2-2.5: 1.

In one embodiment of the present invention, the purification is performed after the step 1), and the compound II is obtained by pouring water into the reaction solution of the step 1), neutralizing the reaction solution with an acid to neutrality, extracting the reaction solution with ethyl acetate, washing the reaction solution with saturated brine, drying the reaction solution, spin-drying the solvent, and recrystallizing the dried product.

The acid is selected from hydrochloric acid or sulfuric acid.

In another embodiment of the present invention, the purification is performed after the step 2), and the solvent in the reaction solution of the step 2) is evaporated to dryness under reduced pressure, and then dichloromethane is added to dissolve the residue, and the dichloromethane layer is washed with water, dried, and the solvent is dried by spinning, and recrystallized to obtain the compound I.

The invention has the advantages and positive effects that:

1. the intermediate compound II (long-chain alkoxy-ethanol/propanol) used in the invention is easy to prepare and can be industrially produced in a large scale;

2. in the process of preparing the adefovir and the tenofovir monoester, the quality of an intermediate and a final product is easy to control;

3. the raw materials used in the invention are easy to obtain and low in price, and the prepared adefovir and tenofovir monoester have lower cost;

4. is easy for industrialized production.

Drawings

FIG. 1 is a schematic diagram of the preparation of adefovir and tenofovir monoester prodrug provided by the present invention, wherein R is CH₃Or H; m is 0-8, n is 1-20; x is halogen, methane sulfonic group or p-toluene sulfonic group.

Detailed Description

The present invention is further described below in conjunction with examples, which are to be understood as being illustrative only and in no way limiting to the scope of the invention.

Example 1: synthesis of 2-octadecyloxy-1-ethanol

Bromooctadecane (214.8g, 0.64mol) and ethylene glycol (120g, 1.93mol) were dissolved in 400ml DMSOAnd 400ml Tetrahydrofuran (THF), KOH (144g, 2.56mol) was added and mechanical stirring was carried out at room temperature for 16 h. The reaction solution was poured into 400ml of deionized water and neutralized with 18% HCl (about 250ml) to neutrality. Extracting with ethyl acetate, washing with saturated salt water, and adding anhydrous MgSO₄And (5) drying. After filtration, the filtrate was spin-dried to give a pale yellow waxy solid. Recrystallization from petroleum ether gave 90g (yield 43%) of the compound as a white solid. And Mp: 49-51 ℃.¹H-NMR(CDCl₃)δ(ppm)：0.88(t，J＝6.4Hz，3H)，1.25(m，30H)，1.58(m，2H)，3.47(t，J＝6.8Hz，2H)，3.53(t，J＝4.8Hz，2H)，3.72(t，J＝4.4Hz，2H)。

Example 2: synthesis of 3-hexadecyloxy-1-propanol

3-hexadecyloxy-1-propanol was synthesized from bromohexadecane and 1, 3-propanediol as raw materials and sodium hydroxide as an alkali in a similar manner to example 1. Yield 82%, mp: 37-40 ℃.¹HNMR(CDCl₃) δ (ppm): 0.880(t, 3H), 1.256 (broad singlet, 24H), 1.427(s, 1H), 1.566(p, 2H), 1.818(p, 4H), 3.409-3.795(3 sets of 3 doublets, 6H).

Example 3: synthesis of 3-tetradecyloxy-1-propanol

3-tetradecyloxy-1-propanol was synthesized in a similar manner to example 1, using bromotetradecane and 1, 3-propanediol as raw materials and sodium carbonate as an alkali. Yield 85%, mp: 32-34 ℃;¹HNMR(CDCl₃) δ (ppm): 0.873(t, 3H), 1.309 (broad singlet, 22H), 1.558(p, 2H), 1.823(p, 2H), 2.503(s, 1H), 3.401-3.783 (group 3 doublets, 6H).

Example 4: (R) -9- [2- [ (octadecyloxypropyl) phosphoric acid methoxy group]Propyl radical]Preparation of adenine

Commercial tenofovir (3.99g, 13.9mmol), 2-octadecyloxy-1-ethanol (6.58g, 20.9mmol) and triphenylphosphine (7.35g, 28mmol) were dissolved in a solution of 30ml N, N-dimethylformamide and 30ml THF under nitrogen, and azodicarboxylic acid was added in three portions over 15 minutesDiisopropyl ester (DIAD)5.53ml (27.9mmol) was stirred at room temperature for 36 h. After THF in the reaction solution was evaporated to dryness under reduced pressure, 60ml of methylene chloride was added to dissolve the residue, the methylene chloride layer was washed with water, and then anhydrous Na was added₂SO₄And (5) drying. After filtration, the filtrate was spin-dried, and 100ml of diethyl ether was added to the residual solution, stirred for 1 hour, and filtered to obtain 4.8g of a white solid. The obtained solid was dissolved in 60ml of methanol and 1ml of dichloromethane under reflux, and crystallized by cooling to obtain 4.0g of a white solid (yield: 49.3%). And Mp: 144-146 ℃;¹H-NMR(400MHz，C₅D₅N+D₂O)δ(ppm)：1.10(t，J＝6.8Hz，3H)，1.38(d，J＝6.4Hz，3H)，1.52(m，30H)，1.82(m，2H)，3.72(t，J＝6.4Hz，2H)，4.03(t，J＝4.8Hz，2H)，4.36-4.64(m，4H)，4.76-4.79(m，3H)，8.53(s，1H)，8.80(s，1H)；¹³C-NMR(400MHz，DMSO-d6)δ：13.9，17.0，22.1，25.6，28.9，31.3，46.4，57.2，62.7，70.2，74.5，118.3，141.9，149.8，152.2，155.8；³¹P-NMR(400MHz DMSO-d₆)δ(ppm)：+12.904；MS(FAB)m/z：584.2[M+H]⁺.

example 5: (R) -9- [2- [ (hexadecyloxypropyl) phosphoric acid methoxy group]Propyl radical]Adenine

PMPA and 3-hexadecyloxy-1-propanol as raw materials, pyrrole and acetone as aprotic solvent, and (R) -9- [2- [ (hexadecyloxypropyl) methoxyphosphoric acid prepared by the method similar to that of example 4]Propyl radical]Adenine. Yield 71.5%, mp: 130 ℃ to 132 ℃;¹HNMR(DMSO)δ(ppm)：0.838(t，3H)，0.919-0.933(d，3H)，1.134-1.225(m，26H)，1.414-1.475(m，2H)，1.606-1.638(m，2H)，3.128-3.416(m，6H)，3.642(s，2H)，3.837-3.850(m，1H)，4.084-4.269(m，2H)，7.109(s，2H)，8.098(s，1H)，8.345(s，1H)。MS-ESI：570(M+1)。

example 6: (R) -9- [2- [ (tetradecyloxypropyl) phosphoryl methoxy group]Propyl radical]Adenine

PMPA and 3-tetradecyloxy-1-propanol were used as raw materials, and (R) -9- [2- [ (tetradecyloxy-propyl) phosphomethoxylphosphate was synthesized in a similar manner to that of example 4]Propyl radical]Adenine. Yield 78%, mp: 127-129 ℃;¹HNMR(DMSO)δ(ppm)：0.838(t，3H)，0.944(d，3H)，1.151-1.227(m，22H)，1.379-1.394(m，2H)，1.637(m，2H)，3.196-3.416(m，6H)，3.709(s，2H)，3.843-3.856(m，1H)，4.138-4.209(m，2H)，7.122(s，2H)，8.098(s，2H)。MS-ESI：542(M+1).

example 7: 9- [2- [ (octadecyloxyethyl) phosphoric acid methoxy ester]Ethyl radical]Adenine

9- [2- [ (octadecyloxyethyl) phosphoric acid methoxy ] methyl ester is synthesized by the similar method of the example 4 by taking PMEA and 2-octadecyloxy-1-ethanol as raw materials, taking azodicarboxylic acid Diethyl Ester (DEAD) as a mitsunobu agent and pyridine and acetonitrile as aprotic solvents]Ethyl radical]Adenine. The yield thereof was found to be 69%. mp: 197 ℃ and 199 ℃.¹HNMR(DMSO)δ(ppm)：0.789(t，3H)，1.205(m，22H)，1.377(m，2H)，1.613(m，2H)，3.206-3.438(m，6H)，3.705(s，2H)，3.816(m，2H)，4.269(m，2H)，7.130(s，2H)，8.092-8.172(m，2H)。

Example 8: 9- [2- [ (hexadecyloxypropyl) phosphoryl methoxy]Ethyl radical]Adenine

PMPA and 3-hexadecyloxy-1-propanol were used as raw materials to synthesize 9- [2- [ (hexadecyloxypropyl) phosphomethoxylphosphate in a similar manner to that of example 7]Ethyl radical]Adenine. Yield 73%, mp: 188 ℃ and 191 ℃.¹HNMR(DMSO)δ(ppm)：0.836(t，3H)，1.198(m，26H)，1.403(m，2H)，1.601(m，2H)，3.217-3.401(m，6H)，3.654(s，2H)，3.804(m，2H)，4.254(m，2H)，7.123(s，2H)，8.098(m，2H)。MS-ESI：556(M+1)。

Example 9: 9- [2- [ (tetradecyloxypropyl) phosphorylmethoxy]Ethyl radical]Adenine

9- [2- [ (tetradecyloxypropyl) phosphomethoxylmethoxy ] 9 was synthesized from PMEA and 3-tetradecyloxy-1-propanol in a similar manner to that of example 7]Ethyl radical]Adenine. The yield thereof is 69%，mp：178-181℃。¹HNMR(DMSO)δ(ppm)：0.838(t，3H)，1.205(m，22H)，1.377(m，2H)，1.613(m，2H)，3.206-3.438(m，6H)，3.705(s，2H)，3.816(m，2H)，4.269(m，2H)，7.130(s，2H)，8.097(m，2H)。MS-ESI：528(M+1)。

Claims (12)

1. A preparation method of acyclic nucleoside antiviral drug phosphate monoester compound with the structure shown in the general formula I,

wherein R is CH₃Or H; m =0-8, n = 1-20;

the method comprises the following specific steps:

1) dissolving substituted alkane and dihydric alcohol in aprotic solventAdding alkali, reacting at room temperature for 10-16 h to obtain compound II HOCH₂(CH₂)_mCH₂OCH₂(CH₂)_nCH₃The substituted alkane is C3-C22 alkane substituted by halogen, methane sulfonyl oxygen or p-toluene sulfonyl oxygen, the dihydric alcohol is C2-C10 straight-chain alkane containing two hydroxyl groups, and the two hydroxyl groups are positioned at two ends of the C2-C10 straight-chain alkane;

2) dissolving an acyclic nucleoside antiviral drug, a compound II and triphenylphosphine in an aprotic solvent, adding a dehydration reagent for three times, and stirring at room temperature to react to obtain a compound I, wherein the dehydration reagent is diisopropyl azodicarboxylate or diethyl azodicarboxylate;

the acyclic nucleoside antiviral drug is adefovir or tenofovir.

2. The method according to claim 1, wherein the substituted alkane is preferably a long-chain alkane of C12-C18 substituted with bromine.

3. The production method according to claim 1, wherein the diol is preferably ethylene glycol or 1, 3-propylene glycol.

4. The process according to claim 1, wherein the aprotic solvent is selected from benzene, diethyl ether, tetrahydrofuran, carbon tetrachloride, dimethyl sulfoxide, N-dimethylformamide, N-dimethylacetamide, acetone, acetonitrile, hexamethylphosphoramide, pyridine or pyrrole.

5. The method according to claim 4, wherein the aprotic solvent is selected from the group consisting of dimethyl sulfoxide, N-dimethylformamide and tetrahydrofuran.

6. The method of claim 1, wherein the base is selected from the group consisting of sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium carbonate and potassium carbonate.

7. The method according to claim 6, wherein the base is sodium hydroxide or potassium hydroxide.

8. The preparation method according to claim 1, wherein the dehydrating reagent is diisopropyl azodicarboxylate or diethyl azodicarboxylate, and the molar ratio of the dehydrating reagent to the acyclic nucleoside antiviral drug is 1-5: 1.

9. The method of claim 8, wherein the molar ratio of the dehydrating reagent to the acyclic nucleoside antiviral drug is 2-2.5: 1.

10. The process according to claim 1, wherein the purification is carried out after the step 1), by pouring water into the reaction solution of the step 1), neutralizing the reaction solution with an acid to neutrality, extracting the reaction solution with ethyl acetate, washing the reaction solution with saturated brine, drying the reaction solution, draining the solvent, and recrystallizing the reaction solution to obtain the compound II.

11. The method of claim 10, wherein the acid is selected from hydrochloric acid or sulfuric acid.

12. The preparation method according to claim 1, wherein the purification is performed after the step 2), and the solvent in the reaction solution of the step 2) is evaporated to dryness under reduced pressure, and then dichloromethane is added to dissolve the residue, and the dichloromethane layer is washed with water, dried, and the solvent is dried by spinning, and then the compound I is obtained after recrystallization.