阅读说明：本技术 一种替卡格雷关键手性中间体异构体杂质tgad1的制备方法 (Preparation method of ticagrelor key chiral intermediate isomer impurity TGAD1 ) 是由 金生华 金晓峰 曹鹏 于 2021-08-11 设计创作，主要内容包括：本发明涉及用替卡格雷关键光学活性中间体TGA制备其异构体杂质TGAD1的方法。该方法经过Cbz保护、氧化反应、还原反应、酯化反应、脱保护反应等步骤制备得到TGAD1,该方法反应条件简单温和、后处理方便、具有较高的精制收率和纯度,制备所得样品可进一步用作替卡格雷中间体的杂质对照品,有利于提高替卡格雷的质量控制。(The invention relates to a method for preparing an isomer impurity TGAD1 of a key optically active intermediate TGA of ticagrelor. The TGAD1 is prepared by the steps of Cbz protection, oxidation reaction, reduction reaction, esterification reaction, deprotection reaction and the like, the method has the advantages of simple and mild reaction conditions, convenient post-treatment and higher refining yield and purity, and the prepared sample can be further used as an impurity reference substance of a ticagrelor intermediate, thereby being beneficial to improving the quality control of ticagrelor.)

1. A preparation method of a key chiral intermediate isomer impurity TGAD1 of ticagrelor comprises the following steps:

(1) TGA is protected by Cbz in the presence of a basic reagent to obtain a compound 11;

(2) compound 11 is oxidized into carbonyl by oxidation reaction to obtain compound 12;

(3) carrying out asymmetric reduction reaction on the compound 12 to obtain a compound 13;

(4) carrying out esterification reaction on the compound 13 to obtain a compound 14;

(5) carrying out deprotection reaction on the compound 14, and removing a benzyloxycarbonyl protecting group to obtain a compound 15;

(6) carrying out oxidation reaction on the compound 15 to obtain a compound 16;

(7) compound 16 produces TGAD1 by an asymmetric reduction reaction.

2. The preparation method according to claim 1, wherein the alkaline reagent used in step (1) is one or more of potassium carbonate, sodium carbonate, potassium hydroxide, sodium bicarbonate and/or potassium bicarbonate, and the molar ratio of the alkaline reagent to the TGA is 1.5: 1-2.5: 1; the protective agent used in the step (1) is benzyl chloroformate, and the molar ratio of the protective agent to the TGA is 1.4: 1-1.6: 1.

3. The method according to claim 1, wherein the oxidizing agent used in step (2) is TEMPO-sodium hypochlorite, TEMPO-sodium hypobromite or TEMPO-iodobenzene diacetate; the reaction solvent used in the step (2) is acetonitrile-water, tetrahydrofuran-water or dichloromethane-water; the reaction temperature of the step (2) is not more than 15 ℃.

4. The preparation method according to claim 1, wherein the reducing agent used in the step (3) is sodium borohydride, potassium borohydride, lithium aluminum hydride or diborane, and the molar ratio of the reducing agent to the compound 12 is 1.4:1 to 1.6: 1; the reaction solvent used in the step (3) is methanol, ethanol or isopropanol.

5. The production method according to claim 1, wherein the deprotection agent used in the step (5) is H₂/Pd-C、H₂/Pd(OH)₂、H₂/PdCl₂、HCOOH/Pd-C、NH₂NH₂Pd-C or cyclohexene/Pd-C.

6. The preparation method according to claim 1, wherein the oxidant used in step (6) is sodium tungstate-hydrogen peroxide, potassium tungstate-hydrogen peroxide, ammonium tungstate-hydrogen peroxide, tungsten nitrate-hydrogen peroxide, or tungsten sulfate-hydrogen peroxide; the reaction temperature of the step (6) is not more than 50 ℃.

7. The method according to claim 1, wherein the reducing agent used in step (7) is lithium aluminum hydride, sodium borohydride, or H₂Pd-C or zinc powder/acetic acid; the reaction temperature of the step (7) is not more than 35 ℃.

8. The method of claim 1, further comprising the step of purifying:

(8) TGAD1 was reacted with benzyl chloroformate to afford compound 17 and purified;

(9) deprotection of compound 17 affords purified TGAD 1.

9. The production method according to claim 8, wherein the deprotection agent used in the step (9) is H₂/Pd-C、H₂/Pd(OH)₂、H₂/PdCl₂、HCOOH/Pd-C、NH₂NH₂Pd-C or cyclohexene/Pd-C.

10. Use of the key chiral intermediate isomer of ticagrelor, TGAD1, obtained according to any one of claims 1 to 9 as an impurity control.

Technical Field

The invention relates to the field of medicinal chemistry, and in particular relates to a preparation method of a key chiral intermediate isomer impurity TGAD1 of ticagrelor.

Background

Impurities in the medicine are main factors influencing the purity of the medicine, and if the impurities in the medicine exceed the limited requirements specified by quality standards, the appearance and the physical and chemical parameters of the medicine are possibly changed, even the stability of the medicine is influenced, so that the activity of the medicine is reduced, the toxic and side effects are increased, and the product quality of the medicine and the medication safety of patients are seriously damaged.

Ticagrelor is a novel selective small molecule anticoagulant developed by astrazep, and the key chiral intermediate TGA structure of ticagrelor is as follows:

TGA has four chiral centers, and various isomer impurities are generated in the actual synthesis process and the storage process, so that the directional synthesis of an isomer impurity reference substance becomes very important in order to improve the product quality and the medication safety of patients.

There is no report about the preparation of the isomer impurity TGAD1 from TGA as the starting material.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: the preparation method of the key chiral intermediate isomer impurity TGAD1 of ticagrelor has the advantages of simple and mild reaction conditions, high refining yield and purity and the like.

The technical scheme for solving the technical problems is as follows:

the invention provides a preparation method of a key chiral intermediate isomer impurity TGAD1 of ticagrelor, which comprises the following steps:

(1) TGA is protected by Cbz in the presence of a basic reagent to obtain a compound 11;

(2) compound 11 is oxidized into carbonyl by oxidation reaction to obtain compound 12;

(3) carrying out asymmetric reduction reaction on the compound 12 to obtain a compound 13;

(4) carrying out esterification reaction on the compound 13 to obtain a compound 14;

(5) carrying out deprotection reaction on the compound 14, and removing a benzyloxycarbonyl protecting group to obtain a compound 15;

(6) carrying out oxidation reaction on the compound 15 to obtain a compound 16;

(7) compound 16 is subjected to asymmetric reduction to prepare TGAD 1;

further, the alkaline reagent used in the step (1) is one or more of potassium carbonate, sodium carbonate, potassium hydroxide, sodium bicarbonate and/or potassium bicarbonate, preferably potassium carbonate; the molar ratio of the alkaline reagent to the TGA is 1.5: 1-2.5: 1, preferably 2: 1; the protective agent used in the step (1) is benzyl chloroformate, and the molar ratio of the protective agent to the TGA is 1.4: 1-1.6: 1, preferably 1.5: 1;

further, the oxidant used in the step (2) is TEMPO-sodium hypochlorite, TEMPO-sodium hypobromite or TEMPO-iodobenzene diacetate, preferably TEMPO-sodium hypochlorite; the reaction solvent used in the step (2) is acetonitrile-water, tetrahydrofuran-water or dichloromethane-water, preferably dichloromethane-water; the reaction temperature of the step (2) is not more than 15 ℃, and preferably not more than 10 ℃;

further, the reducing agent used in step (3) is sodium borohydride, potassium borohydride, lithium aluminum hydride or diborane, preferably sodium borohydride; the molar ratio of the reducing agent to the compound 12 is 1.4: 1-1.6: 1, preferably 1.5: 1; the reaction solvent used in the step (3) is methanol, ethanol or isopropanol, preferably methanol;

further, the deprotection agent used in the step (5) is H₂/Pd-C、H₂/Pd(OH)₂、H₂/PdCl₂、HCOOH/Pd-C、NH₂NH₂Pd-C or cyclohexene/Pd-C, preferably H₂/Pd-C；

Further, the oxidant used in the step (6) is sodium tungstate-hydrogen peroxide, potassium tungstate-hydrogen peroxide, ammonium tungstate-hydrogen peroxide, tungsten nitrate-hydrogen peroxide or tungsten sulfate-hydrogen peroxide, preferably sodium tungstate-hydrogen peroxide; the reaction temperature of the step (6) is not more than 50 ℃, preferably not more than 45 ℃;

further, the reducing agent used in the step (7) is lithium aluminum hydride, sodium borohydride, H₂Pd-C or zinc powder/acetic acid, preferably lithium aluminum hydride; the molar ratio of lithium aluminum hydride to compound 16 is preferably 1: 1; the reaction temperature of the step (7) is not more than 35 ℃, and preferably not more than 30 ℃;

further, the preparation method of the TGAD1 provided by the invention also comprises the following purification steps:

(8) TGAD1 was reacted with benzyl chloroformate to afford compound 17 and purified;

(9) deprotection of compound 17 affords purified TGAD 1;

further, the deprotection agent used in the step (9) is H₂/Pd-C、H₂/Pd(OH)₂、H₂/PdCl₂、HCOOH/Pd-C、NH₂NH₂Pd-C or cyclohexene/Pd-C, preferably H₂/Pd-C；

The invention also provides application of the key chiral intermediate isomer impurity TGAD1 of ticagrelor obtained by the preparation method in serving as an impurity reference substance.

The Chinese naming of the compound of the invention conflicts with the structural formula, and the structural formula is taken as the standard; except for obvious errors in the formula.

The invention has the beneficial effects that: the preparation method of the brand new ticagrelor key chiral intermediate isomer impurity TGAD1 is provided, the reaction conditions are simple and mild, the post-treatment is convenient, the refining yield and the purity are high, and the prepared sample can be further used as an impurity reference substance of a ticagrelor intermediate.

Detailed Description

The invention is illustrated but not limited by the following examples. The technical solutions protected by the present invention are all the simple replacements or modifications made by the skilled person in the art.

Example 1:

(1) TGA (80g,0.4624mol) was dissolved in 250mL tetrahydrofuran, 200mL water was added, and potassium carbonate (127.62g,0.9248mol) was added. Stirring to dissolve, cooling to 0 ℃, dropwise adding benzyl chloroformate (118.33g,0.6936mol), stirring at room temperature for 5min after dropwise adding, completely converting the raw materials, demixing, adding 150mL of ethyl acetate to extract a water layer, and combining organic layers. Dried over anhydrous sodium sulfate and concentrated to give 110g of product (HPLC: 95%);

(2) a compound of formula 11 (100g,0.3256mol), sodium bromide (16.75g,0.1628mol), sodium bicarbonate (32.8g, 0.3905mol), TEMPO (763mg,4.884mmol) were added to a 5000mL three-necked flask, 1L of dichloromethane and 1L of water were added, and the mixture was stirred to dissolve. The temperature is reduced to 0 ℃, sodium hypochlorite solution (8% w,800mL) is slowly dripped, and the temperature is controlled not to exceed 10 ℃. After dropping, the temperature is kept for 10 minutes. TLC detection shows iodine, and the raw materials are completely converted. The developing agent is n-hexane: ethyl acetate 2: 1. 100g of sodium sulfite solid was added and stirred for 10 minutes to quench the reaction. The layers were separated, 500mL of dichloromethane was added to extract the aqueous layer, the organic layers were combined, the organic layer was washed with saturated brine, dried over anhydrous sodium sulfate, and spin-dried to give an orange solid. Adding 40mL of ethyl acetate into a reaction bottle, refluxing, dissolving, cooling to 50 ℃, slowly adding 500mL of n-hexane, separating out solids in the dropping process, naturally cooling to room temperature after dropping, and stirring for crystallization for 2 hours. Suction filtration is carried out, the filter cake is rinsed by a small amount of n-hexane and air-dried for 4 hours at 45 ℃ to obtain 85g of white solid (HPLC: 98%) with 85% yield.

(3) The compound of formula 12 (65g,0.2130mol) was dissolved in 650mL of methanol and cooled to 0 ℃. Sodium borohydride (12.1g,0.3198mol) was added in portions with bubble generation, the temperature was controlled not to exceed 10 ℃. After the addition, the mixture was stirred at room temperature for 10 minutes. TLC detection shows iodine, and the raw materials are completely converted. The developing agent is n-hexane: ethyl acetate 2: 1. Adding water to quench and react, evaporating the reaction solution until no drop occurs, extracting the water layer with ethyl acetate (300mL x 3) for three times, combining the organic layers, washing with saturated sodium chloride, and drying with anhydrous sodium sulfate. The organic layer was spin dried and n-hexane was added and slurried overnight. Suction filtration and rinsing the filter cake with a small amount of n-hexane. Forced air drying at 45 ℃ for 4 hours gave 62g (HPLC: 95%) of a white solid with a yield of 95%.

(4) The compound of formula 13 (60g,0.1954mol) was dissolved in 600mL of dichloromethane, triethylamine (39.5g,0.3904mol) was added, acetic anhydride was added at room temperature with stirring, and after the addition was completed, the mixture was refluxed for 24 hours. TLC detection, complete conversion of the raw material. The developing agent is n-hexane and ethyl acetate which are 2: 1. The reaction was quenched by adding 500mL of saturated sodium bicarbonate and stirring at room temperature for 30 min. The layers were separated and the aqueous layer was extracted with 500mL of dichloromethane, the organic layers were combined, washed with saturated sodium chloride, dried over anhydrous sodium sulfate and spin dried to give 81g of a brown oil (purified as the next step after oxime formation).

(5) The compound of formula 14 (81g crude) was dissolved in 600mL of methanol, 6g of 10% Pd/C was added, replaced with hydrogen three times, and stirred at room temperature overnight. TLC detection shows iodine, and the raw materials are completely converted. The developing solvent is dichloromethane-methanol 5: 1. Suction filtration was carried out, and the filter cake was rinsed with 100mL of methanol and spin-dried to give 64g of a pale yellow oil. (purification after oxime formation, directly next step).

(6) Dissolving the compound (64g crude product) in the formula 15 in 600mL methanol and 60mL water, adding sodium tungstate (114.7g,0.3904mol), stirring to dissolve, cooling in ice-water bath, dropwise adding hydrogen peroxide (19.92g, 0.5856mol), controlling the temperature not to exceed 45 ℃, and stirring for 4 hours at room temperature after the addition is finished. TLC detection, potassium permanganate color development, dichloromethane and methanol 5:1 as developing agent and one drop of triethylamine. Adding 250mL of water and 113g of ammonium sulfite, stirring at room temperature for 30min, controlling the temperature not to exceed 45 ℃, and developing the color by using a starch potassium iodide test paper. The mixture was rotary-evaporated to no drop, extracted three times with 500mL of dichloromethane, and the organic layers were combined, washed with 100mL of saturated brine, and dried over anhydrous sodium sulfate. And (3) spin-drying, pulping by 60mL of methyl tert-ether, adding 60mL of n-hexane, and stirring for crystallization for 1 h. Suction filtration, 50mL of n-hexane rinse the filter cake, 50 ℃ forced air drying, to give 30g (HPLC: 94%) of a pale yellow powder.

(7) Suspending lithium aluminum hydride (4.64g,0.1223mol) in tetrahydrofuran (60mL), reducing the temperature to 0 ℃ under the protection of nitrogen, and dropwise adding 60mL of a tetrahydrofuran solution of a compound (28g,0.1223mol) of formula 16, wherein the temperature is controlled not to exceed 30 ℃. After dropping, the mixture was stirred at room temperature for 24 hours. And (4) TLC detection, wherein a developing solvent is dichloromethane and methanol which are 3: 1. The temperature is reduced to 0 ℃, and 80mL of ethyl acetate, 80mL of 10% sodium hydroxide aqueous solution and 280mL of water are added in turn to quench and react. A large amount of bubbles are generated, the heat is intensely released, and the temperature is controlled not to exceed 30 ℃. After dripping, stirring for 30min at room temperature, carrying out suction filtration, and rinsing the filter cake with 300mL of tetrahydrofuran until no product exists in the rinsing liquid; the filtrate was dried by rotary evaporation to give 33g of crude TGAD1 oil.

(8) TGAD1(33g crude) was dissolved in 330mL tetrahydrofuran, 50mL water was added, and potassium carbonate (33.5g, 0.2423moL) was added. Stirring to dissolve, cooling to 0 ℃, dropwise adding benzyl chloroformate (35.86g,0.2102mol), stirring at room temperature for 5min after dropwise adding, completely converting raw materials, separating layers, extracting an aqueous layer with 150mL of ethyl acetate, and combining organic layers. Dried over anhydrous sodium sulfate. Column chromatography, conditions: hexane Ethyl acetate 3:1 → Hexane Ethyl acetate 2:1 → Hexane Ethyl acetate 3:2 gradient elution gave 12g (HPLC: 96%) of the compound of formula 17.

(9) The compound of formula 17 (10g,0.03257mol) was dissolved in 100mL of methanol, 1g of 10% Pd/C was added, hydrogen gas was substituted three times, and the mixture was stirred at room temperature overnight. TLC detection shows iodine, and the raw materials are completely converted. The developing solvent is dichloromethane methanol 3: 1. Suction filtration, filter cake rinsing with 50mL methanol, spin drying to get colorless oil 5.5 g. 500mL of n-hexane was added and slurried, and the white solid was suction-filtered and vacuum-dried to obtain 5.2g of a white solid (optical purity 99.2%) as a TGAD1 refined product in a one-step reaction yield of 92.3%.

MS:m/z＝174.2(M+H⁺)；

¹H-NMR(400MHz,DMSO-d6)：δ4.66(t,1H),4.34(d,1H),4.15(m,1H),3.53(m,1H),2.21-2.05(m,2H),1.39(s,3H),1.24(s,3H)。

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various changes and modifications can be made without departing from the inventive concept of the present invention, and these changes and modifications are all within the scope of the present invention.