Preparation method of sphaelactone derivative

Abstract

According to the invention, the 3S-isomer of DMAMCL is found for the first time, and a method for effectively controlling the content of the 3S-isomer (below 0.4%) is researched, so that the 3S-isomer can be used for preparing an ACT001 compound meeting a scalar standard.

Description

Technical Field

[0001] The invention belongs to the field of drug preparation, and particularly relates to a method for preparing a Michelia lactone derivative. Background Art

[0002] ACT001 is the fumarate form of dimethylamino Michelia lactone (DMAMCL), a Michelia lactone derivative synthesized by the dimethylamino Michael addition reaction of Michelia lactone (MCL). ACT001 is an orally active PAI-1 inhibitor that inhibits the phosphorylation of PI3K and AKT and can directly bind to STAT3 to inhibit STAT3 phosphorylation and PD-L1 expression. ACT001 can cross the blood-brain barrier and has strong anti-glioblastoma (GBM) activity and immunomodulatory effects.

[0003] ACT001 is synthesized from parthenolide (PTL) through a three-step chemical reaction. Most of its multiple chiral centers come from the main raw material PTL, and only one of the chiral centers is synthesized (MCL→DMAMCL).

[0004]

[0005] Literature reports that the chiral center synthesized in the process of preparing DMAMCL by the addition reaction of MCL with dimethylamine is mostly R-configuration, and no S-configuration (3S-isomer) has been reported. The present invention has confirmed that the 3S-isomer is produced in the addition reaction, and the isomer will be introduced into ACT001, thereby affecting the product quality of ACT001. The study also found that if commercially available dimethylamine tetrahydrofuran (2.0M) and MCL are directly added, the 3S-isomer is about 1.0%, and the isomer exceeds the scalar standard (isomer is not more than 0.1%) after salt formation; therefore, it is necessary to further explore and study the control of the addition isomer so that its content in DMAMCL is controlled below 0.4%, so as to ensure that the corresponding single impurity of the final product is less than 0.1%. Summary of the invention

[0006] To improve the above technical problems, the present invention provides a method for preparing dimethylamino diatomaceous lactone (DMAMCL), comprising the following step 2: under low temperature conditions, dissolving the compound MCL and dimethylamine hydrochloride in an organic solvent, and then adding an organic amine to obtain the compound DMAMCL.

[0007]

[0008] According to an embodiment of the present invention, the low temperature is -20 to 15°C, such as -15 to 10°C, preferably -5 to 5°C or 0 to 5°C.

[0009] According to an embodiment of the present invention, the organic amine is selected from tertiary amines, such as one or more of triethylamine, DBU, DIEA, tripropylamine, DMAP, and tetramethyldiamine.

[0010] According to an embodiment of the present invention, the organic solvent is selected from one or more of methanol, ethanol, isopropanol, tetrahydrofuran, 2-methyltetrahydrofuran, dioxane, ether, methyl tert-butyl ether, ethyl acetate, toluene, acetonitrile, DMF, dichloromethane, chloroform, and acetone.

[0011] According to an embodiment of the present invention, the adding method may be batch adding or dropwise adding.

[0012] According to an embodiment of the present invention, the molar ratio of MCL to dimethylamine hydrochloride is 1:(1-5), for example 1:(1.5-3), such as 1:2, 1:2.5;

[0013] According to an embodiment of the present invention, the reaction time is 1-48 h, for example 2-6 h, such as 2.5 h, 3 h, 3.5 h, 4 h, 4.5 h.

[0014] According to an embodiment of the present invention, the method can control impurities (3S-isomer) of the following structure:

[0015]

[0016] According to an embodiment of the present invention, the method can control the content of impurities to be below 0.4%, for example, below 0.35%, below 0.3%, below 0.25%, below 0.2%, below 0.15%, and below 0.1%.

[0017] The present invention also provides a method for preparing the compound ACT001, comprising the following steps:

[0018]

[0019] Step 2: Prepare DMAMCL according to the method described above.

[0020] Step 3: Compound DMAMCL is dissolved in an aqueous solution of fumaric acid to react and obtain compound ACT001.

[0021] According to an embodiment of the present invention, an organic solvent may be added to the aqueous solution of fumaric acid in step 3, and the organic solvent is, for example, acetone.

[0022] The present invention also provides a method for preparing the compound ACT001, comprising the following steps:

[0023]

[0024] Step 2: Under low temperature conditions, dissolving the compound MCL and dimethylamine hydrochloride in an organic solvent, and then adding an organic amine to obtain the compound DMAMCL;

[0025] Step 3: Compound DMAMCL is dissolved in an aqueous solution of fumaric acid to react and obtain compound ACT001;

[0026] According to an embodiment of the present invention, in step 2, the low temperature is -20 to 15°C, such as -15 to 10°C, preferably -5 to 5°C or 0 to 5°C.

[0027] According to an embodiment of the present invention, in step 2, the organic amine is selected from tertiary amines, such as one or more of triethylamine, DBU, DIEA, tripropylamine, DMAP, and tetramethyldiamine.

[0028] According to an embodiment of the present invention, the organic solvent in step 2 is selected from chlorine solvents, such as dichloromethane and chloroform;

[0029] According to an embodiment of the present invention, in step 2, the adding method can be batch adding or dropwise adding.

[0030] According to an embodiment of the present invention, in step 2, the molar ratio of MCL to dimethylamine hydrochloride is 1:(1-5), for example 1:(1.5-3), such as 1:2, 1:2.5;

[0031] According to an embodiment of the present invention, in step 2, the reaction time is 1-48 h, for example, 2-6 h, such as 2.5 h, 3 h, 3.5 h, 4 h, 4.5 h.

[0032] According to an embodiment of the present invention, an organic solvent may be added to the aqueous solution of fumaric acid in step 3, and the organic solvent is, for example, acetone.

[0033] According to an exemplary embodiment of the present invention, a method for preparing the compound DMAMCL comprises the following steps:

[0034] At 0-5°C, dimethylamine hydrochloride, MCL and water (or no water) are added to dichloromethane, stirred, the temperature is controlled at 0-5°C, TEA solution is added dropwise, and reacted at 0-5°C to obtain the dimethylamino mirifica lactone (DMAMCL);

[0035] According to an embodiment of the present invention, the preparation method further comprises a post-treatment step: after the reaction is completed, water and a 20% HCl aqueous solution are added to separate the liquids; a 10% NaOH solution is added to the aqueous phase, and the product is precipitated from the water, filtered, washed, and then dried to obtain dimethylamino Michelia lactone (DMAMCL).

[0036] According to an embodiment of the present invention, the method for preparing the compound MCL comprises the following steps 1: the compound parthenolide (PTL) undergoes a rearrangement reaction under the action of a catalyst to obtain the compound MCL;

[0037]

[0038] According to an embodiment of the present invention, the catalyst is selected from p-toluenesulfonic acid (PTSA), such as p-toluenesulfonic acid monohydrate.

[0039] According to an embodiment of the present invention, the step 1 may further include a purification step 1-1: recrystallizing the obtained compound MCL in acetone to obtain a purified compound MCL.

[0040] Beneficial Effects

[0041] The present invention discovers the 3S-isomer of DMAMCL for the first time through experiments. The preparation method provided by the present invention can effectively control the content of the 3S isomer (less than 0.4%), thereby ensuring that it can be used to prepare the ACT001 compound that meets the scalar standard. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 3S-isomer 1 H NMR spectrum.

[0043] Figure 2 3S-isomer 13 C NMR spectrum.

[0044] Figure 3 This is the DEPT135 spectrum of the 3S-isomer.

[0045] Figure 4 This is the COSY spectrum of the 3S-isomer.

[0046] Figure 5 This is the HMBC spectrum of the 3S-isomer.

[0047] Figure 6 This is the HSQC spectrum of the 3S-isomer. DETAILED DESCRIPTION

[0049] The technical solution of the present disclosure will be further described in detail below in conjunction with specific embodiments. It should be understood that the following embodiments are only exemplary illustrations and explanations of the present disclosure and should not be construed as limiting the scope of protection of the present disclosure. All technologies implemented based on the above content of the present disclosure are included in the scope of protection intended by the present disclosure.

[0050] Unless otherwise specified, the raw materials and reagents used in the following examples are commercially available or can be prepared by known methods.

[0051] Unless otherwise specified, the 3S isomer content involved in the present invention is calculated by the area normalization method.

[0052] The preparation method of synthesizing ACT001 in the embodiment of the present invention mainly involves the following reaction route:

[0053]

[0054] Example 1 Preparation of Compound MCL

[0055] Under nitrogen protection, at 20±5°C, dichloromethane DCM (600g) and p-toluenesulfonic acid monohydrate (7.5g) were added to the reaction bottle. The temperature was controlled at 20±5°C, and a dichloromethane DCM (2700g) solution of PTL (300g) was slowly added to the system. After the addition was completed, the reaction was continued at 20±5°C until the percentage of PTL was less than or equal to 3.0%. After the reaction was completed, a NaHCO3 / H2O aqueous solution was slowly added to the system, stirred, allowed to stand, and layered, and the organic phase was collected; then washed with NaCl / H2O solution, layered, filtered, desolvated, and dried to obtain a crude product of Michelia lactone (MCL). Under nitrogen protection, acetone (600g) and crude MCL were added to the reaction bottle, stirred and heated to clarify, then cooled, crystallized, filtered, washed, and dried to obtain 117g of MCL refined product, HPLC purity: 98.833%.

[0056] Example 2 Preparation of compound DMAMCL

[0057] General method: add dimethylamine hydrochloride (DMA.HCl), MCL and water (or no water) to dichloromethane at 0-5°C, stir, control the temperature at 0-5°C, add TEA / DCM solution dropwise, and react at 0-5°C; use HPLC to detect the degree of reaction, remove the solvent under reduced pressure after the raw material is completely converted; after desolventizing, use dichloromethane to redissolve the product, wash with water, and layer it; add water and 20% HCl aqueous solution to the organic phase, separate the liquids; wash with DCM, layer it, collect the aqueous phase, and desolventize; add 10% NaOH solution to the desolventized aqueous phase, the product is precipitated from the water, filtered, washed, and dried to obtain dimethylamino-methylene lactone (DMAMCL), and the characterization data of its 3S isomer are shown in Figures 1 to 6 .

[0058] Specific operation process:

[0059] 1 Ingredients

[0060] 1.1 Weigh 24.80 g of triethylamine and 202.66 g of dichloromethane; stir well and set aside.

[0061] 1.2 Preparation of 20% hydrochloric acid solution: Prepare 20% hydrochloric acid aqueous solution (mix 101.11g 36% hydrochloric acid and 86.67g pure water) in a plastic bucket and cool it to room temperature for use.

[0062] 1.3 Preparation of 10% sodium hydroxide aqueous solution: Prepare 10% sodium hydroxide aqueous solution in a plastic bucket (19.95 g sodium hydroxide and 180.25 g purified water are dissolved and clarified). After the solid is completely dissolved, cool it to room temperature for use.

[0063] 2 Responses

[0064] 2.1 Add 200.12 g of dichloromethane solution, 40.45 g of MCL, 126.62 g of DMA.HCl and 4 mL of water into a 1 L four-necked glass reaction bottle and start stirring.

[0065] 2.2 Turn on the low-temperature coolant circulation pump and start cooling down to 0-5℃.

[0066] 2.3 When the temperature drops to 0-5°C, add the prepared TEA / DCM solution to the reaction solution dropwise for about 1.5 hours.

[0067] 2.4 After the addition is complete, maintain the reaction at 0-5°C and stir for at least 5-6 hours.

[0068] 2.5 Sampling and in-process control (HPLC monitoring: take the reaction solution, blow dry with cold air, and send for inspection. The content of Michelia lactone shall not exceed 5.0%), MCL: 2.831%, 3S-isomer 0.137%.

[0069] 3. Post-processing

[0070] 3.1 After confirming that the reaction is complete, add 120.15 g of water to the reaction solution, stir and wash. Separate the layers, discard the aqueous phase, and collect the organic phase.

[0071] 3.2 Add 200.38 g of purified water to the organic phase; control the temperature at 15-25° C. under stirring, and use prepared 20% hydrochloric acid solution to adjust the pH value of the reaction solution to 2-3 (consume 42.79 g); continue stirring for 15 minutes after adjustment, and stop stirring after retesting the pH value without change, let stand to separate, retain the aqueous phase, and discard the dichloromethane phase; wash the aqueous phase once with 100.01 g of dichloromethane, collect the aqueous phase, and discard the dichloromethane phase; concentrate the aqueous phase under reduced pressure below 25° C. for at least 40-60 minutes (no fraction is left).

[0072] 3.3 After concentration, cool the aqueous phase to 0-10°C, and use the prepared 10% sodium hydroxide solution (consume 61.85 g) to adjust the pH of the aqueous phase to 9-10; after reaching the required pH value, adjust the temperature to 0-5°C and stir and keep warm for 1 hour.

[0073] 3.4 After the insulation is completed, filter and wash the filter cake twice with purified water (80 mL × 2), and drain until no liquid drops.

[0074] 3.5 The obtained product was placed on a plate and vacuum dried. The temperature was controlled at 55±5°C and the vacuum degree was -0.08 to -0.1 MPa. The product was dried under reduced pressure for at least 15 hours. About 40.35 g of the product was obtained. The product was a white or off-white powder and the isomer content was 0.05%.

[0075] 3.6 Pack into medicinal low-density polyethylene bags, seal with polyester / aluminum / polyethylene composite bags for pharmaceutical packaging, and store temporarily at 2-8°C.

[0076] 3.7 Yield: about 84%

[0077] According to the following table, the reaction parameters of the above method were adjusted to prepare the compound DMAMCL:

[0078]

[0079]

[0080]

[0081] Example 3 Preparation of Compound ACT001

[0082] Mix acetone and DMA·MCL and stir until they are completely dissolved, then filter and set aside.

[0083] Dissolve fumaric acid (FA) in a mixed solvent of acetone and water, stir until the solution is clear, and filter for later use.

[0084] Add acetone and water into the reaction kettle, stir and heat to 30±5℃, first add 1 / 2 of the fumaric acid acetone aqueous solution into the reaction system, maintain the temperature at 30±5℃, then simultaneously add the specified amount of DMA·MCL acetone solution and fumaric acid acetone aqueous solution, after the addition is complete, add seed crystals to suspend and grow crystals; then add the remaining acid solution and alkali solution, after the addition is complete, keep the temperature, cool down, filter, wash and dry the ACT001 product.

[0085]

[0086] Comparative Example 1 Preparation of Compound DMAMCL

[0087] Add dichloromethane to the reaction flask, stir, and cool to 0-5°C; weigh sodium hydroxide and add it to the reaction flask, maintain the temperature at 0-5°C; weigh dimethylamine hydrochloride and add it to the reaction flask, stir at 0-5°C until all dimethylamine hydrochloride on the surface of the reaction liquid disappears, stop stirring, let stand to separate, extract the upper clear liquid and use it directly for addition reaction. Weigh DMA / DCM solution and add it to the reaction flask, maintain the reaction temperature at 0-5°C, add MCL and stir to react until MCL is ≤5% by HPLC; then desolventize, dissolve the product DCM, wash with water, adjust the acid, separate, and collect the aqueous phase; remove DCM from the aqueous phase, adjust the base, filter, wash with water, and dry the DMA.MCL product.

[0088]

[0089] As can be seen from the table above, when free DMA aqueous solution is used as the raw material, the content of 3S-isomer generated in the reaction solution exceeds 2%, which cannot meet the requirements for preparing qualified ACT001 (3S-isomer content is less than 0.4%).

[0090] When NaOH is used as a base and reacted with DMA.HCl to prepare a DMA / DCM solution, and then further reacted with MCL, the content of 3S-isomer generated in the reaction solution exceeds 1%; although lowering the reaction temperature and adjusting the amount of DMA can reduce the content of 3S-isomer to a certain extent, the content of 3S-isomer in the reaction solution is still far more than 0.4%, and there is a problem of incomplete reaction of the raw materials.

[0091] Comparative Example 2

[0092] According to the method of Example 3, DMAMCL having a 3S isomer content of 0.96% was used as a raw material, and the content of 3S-isomer in the prepared ACT001 was 0.16%.

[0093] The above is an exemplary description of the implementation of the technical solution of the present disclosure. It should be understood that the protection scope of the present disclosure is not limited to the above-mentioned implementation. Any modification, equivalent substitution, improvement, etc. made by those skilled in the art within the spirit and principle of the present disclosure shall be included in the protection scope of the claims of this application.

Claims

1. A method for preparing dimethylamino diatomaceous lactone (DMAMCL), comprising the following steps: dissolving compound MCL and dimethylamine hydrochloride in an organic solvent under low temperature conditions, and then adding an organic amine to react to obtain the compound DMAMCL; 2. The preparation method according to claim 1, characterized in that: The low temperature is -20 to 15°C, such as -15 to 10°C.

3. The preparation method according to claim 1 or 2, characterized in that: The organic amine is selected from tertiary amines, such as one or more of triethylamine, DBU, DIEA, tripropylamine, DMAP, and tetramethyldiamine; Preferably, the organic solvent is selected from at least one of methanol, ethanol, isopropanol, tetrahydrofuran, 2-methyltetrahydrofuran, dioxane, ether, methyl tert-butyl ether, ethyl acetate, toluene, acetonitrile, DMF, dichloromethane, chloroform and acetone.

4. The preparation method according to any one of claims 1 to 3, characterized in that The adding method can be batch adding or dropwise adding.

5. The preparation method according to any one of claims 1 to 4, characterized in that: The molar ratio of MCL to dimethylamine hydrochloride is 1:(1-5), for example 1:(1.5-3); Preferably, the reaction time is 1-48 h, such as 2-6 h.

6. The preparation method according to any one of claims 1 to 5, characterized in that: The following steps are involved: Under the condition of 0-5°C, dimethylamine hydrochloride, MCL and water (or no water) are added to dichloromethane, stirred, the temperature is controlled at 0-5°C, TEA solution is added dropwise, and the reaction is carried out at 0-5°C to obtain the dimethylamino Michelia lactone; preferably, the preparation method further includes the step of post-treatment: after the reaction is completed, water and 20% HCl aqueous solution are added, and the liquids are separated; 10% NaOH solution is added to the aqueous phase, and the product is precipitated from the water, filtered, washed and dried to obtain dimethylamino Michelia lactone.

7. The preparation method according to any one of claims 1 to 6, wherein the method can control impurities of the following structures: Preferably, the method can control the content of the impurities to be below 0.4%, for example, below 0.35%, below 0.3%, below 0.25%, below 0.2%, below 0.15%, or below 0.1%.

8. A method for preparing compound ACT001, comprising the following steps: Step 2: The preparation method according to any one of claims 1 to 7; Step 3: Compound DMAMCL is dissolved in an aqueous solution of fumaric acid to react and obtain compound ACT001.

9. The preparation method according to claim 9, characterized in that: An organic solvent may also be added to the aqueous solution of fumaric acid in step 3, and the organic solvent is, for example, acetone.

10. The preparation method according to any one of claims 1 to 9, characterized in that: The preparation method of the compound MCL comprises the following steps 1: the compound parthenolide (PTL) undergoes a rearrangement reaction under the action of a catalyst to obtain the compound MCL; Preferably, the catalyst is selected from p-toluenesulfonic acid, such as p-toluenesulfonic acid monohydrate. Preferably, the step 1 may further include a purification step 1-1: recrystallizing the obtained compound MCL in acetone to obtain a purified compound MCL.

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