A method for synthesizing progesterone (2,2,4,6,6,17α,21,21,21-D9) by electrochemically promoted hydrogen-deuterium exchange

Abstract

The invention relates to a method for synthesizing progesterone (2,2,4,6,6,17α,21,21,21-D9) by electrochemically promoted hydrogen-deuterium exchange. The method comprises the following steps: adding progesterone and an electrolyte (such as tetra-n-butylammonium tetrafluoroborate) into a reaction container, uniformly mixing with a reaction solvent, then adding deuterated methanol-D4 into the reaction container under protective atmosphere and stirring conditions, using a carbon material as an electrode, and reacting at a constant current for 5-20 hours; after the reaction is completed, vacuum-drying the reaction solvent, separating and purifying the progesterone (2,2,4,6,6,17α,21,21,21-D9) by silica gel column chromatography, and vacuum-drying an eluent to obtain a pure progesterone (2,2,4,6,6,17α,21,21,21-D9). The synthesis method of the present invention is mild, efficient, and simple to operate, and can achieve rapid and efficient synthesis of progesterone (2,2,4,6,6,17α,21,21,21-D9).

Description

Technical Field

[0001] The invention belongs to the field of synthetic chemistry and relates to a method for synthesizing progesterone (2,2,4,6,6,17α,21,21,21-D9) by electrochemically promoted hydrogen-deuterium exchange. Technical Background

[0002] Progesterone is a natural progestogen secreted by the corpus luteum of the ovary. It has a significant morphological effect on the endometrium stimulated by estrogen in the body and is necessary for maintaining pregnancy. Isotope-labeled progesterone is used as a standard for clinical progesterone testing, which is equivalent to a weight for quality monitoring and is particularly important for clinical disease diagnosis. Progesterone (2,2,4,6,6,17α,21,21,21-D9) is an important internal standard compound. Whether progesterone (2,2,4,6,6,17α,21,21,21-D9) with high purity and high deuteration rate can be efficiently obtained is the basis for whether progesterone can be measured quickly and accurately.

[0003] At present, the method for synthesizing progesterone (2,2,4,6,6,17α,21,21,21-D9) is mainly hydrogen-deuterium exchange, that is, progesterone is exchanged with hydrogen and deuterium in deuterated water to obtain progesterone (2,2,4,6,6,17α,21,21,21-D9). However, the above reaction process often involves strong acid or strong base, which may destroy the structure of progesterone, and multiple exchanges are required. Each treatment requires neutralization, and frequent neutralization and extraction processes will occur. Excessive operations will make it difficult to control the deuteration rate and purity of the product. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a method for synthesizing progesterone (2,2,4,6,6,17α,21,21,21-D9) by electrochemically promoted hydrogen-deuterium exchange in view of the deficiencies of the above-mentioned prior art. The method of the present invention for directly synthesizing progesterone (2,2,4,6,6,17α,21,21,21-D9) from progesterone and deuterated methanol, that is, directly using progesterone as a reactant, using cheap and easily available deuterated methanol as a deuterium source, and performing hydrogen-deuterium exchange reaction under electrochemical conditions, and directly synthesizing progesterone (2,2,4,6,6,17α,21,21,21-D9) in one step, and the subsequent purification process does not need to adjust the pH value and extraction, and directly spin-drying and silica gel column chromatography separation and purification are carried out, which greatly improves the yield, output and purity of progesterone (2,2,4,6,6,17α,21,21,21-D9).

[0005] The technical solution adopted by the present invention to solve the above-mentioned problems is:

[0006] A method for synthesizing progesterone (2,2,4,6,6,17α,21,21,21-D9) by electrochemically promoted hydrogen-deuterium exchange, comprising: using progesterone and deuterated methanol-D4 as raw materials, adding an electrolyte, applying a constant current in a reaction solvent to carry out a deuteration reaction under a protective atmosphere; after the deuteration reaction is completed, separating and purifying by silica gel column chromatography to obtain progesterone (2,2,4,6,6,17α,21,21,21-D9).

[0007] According to the above scheme, the electrolyte is one or more of tetra-n-butylammonium tetrafluoroborate, tetra-ethylammonium tetrafluoroborate, tetra-n-butylammonium chloride, tetra-n-butylammonium acetate, etc., and the concentration range of the electrolyte in the reaction solvent is 0.01-0.05mmol / mL.

[0008] According to the above scheme, the dosage ratio of deuterated methanol to progesterone is: 0.1-1 mL of deuterated methanol is added for every 0.3 mmol of progesterone.

[0009] According to the above scheme, the reaction solvent is one or more of acetonitrile, N,N-dimethylformamide, tetrahydrofuran, acetone, etc. The electrolyte can be ionized in these polar solvents, and the reactants and electrolytes have good solubility in the reaction solvent.

[0010] According to the above scheme, the ratio of the reaction solvent to the progesterone is: 5-10 mL of the reaction solvent is added for every 0.3 mmol of progesterone, that is, the concentration range of the progesterone in the reaction solvent is 0.03-0.06 mmol / mL.

[0011] According to the above scheme, the constant current is 5-20 mA and the reaction time is 5-20 h. The current has an important influence on the smooth implementation of the reaction. If the current is too small, the voltage cannot reach the redox potential of the compound, and if the current is too large, the compound will be over-oxidized.

[0012] According to the above scheme, the protective atmosphere includes but is not limited to one or a mixture of several of nitrogen, inert gas, etc. in any proportion.

[0013] According to the above scheme, the electrode of the carbon material is used as the reaction electrode, which can be carbon cloth, carbon felt, carbon rod, carbon plate, etc.

[0014] According to the above scheme, the deuteration reaction is monitored by nuclear magnetic resonance spectroscopy. When the deuteration rate no longer increases, the deuteration reaction ends.

[0015] Preferably, the present invention provides a more specific method for synthesizing progesterone (2,2,4,6,6,17α,21,21,21-D9) by electrochemically promoted hydrogen-deuterium exchange, comprising the following steps:

[0016] (1) Add progesterone and electrolytes into a reaction vessel and insert electrodes;

[0017] (2) under protective atmosphere and stirring conditions, adding deuterated methanol-D4 and a reaction solvent into the reaction vessel of step (1) and mixing them evenly, and then applying a constant current to carry out a deuterated reaction;

[0018] (3) After the deuteration reaction is completed, the reaction solvent is dried under vacuum, and then the progesterone (2,2,4,6,6,17α,21,21,21-D9) is separated and purified by silica gel column chromatography. The eluent is dried under vacuum to obtain pure progesterone (2,2,4,6,6,17α,21,21,21-D9).

[0019] According to the above scheme, the separation process of silica gel column chromatography is as follows: after the deuteration reaction is completed, the reaction solvent is dried under vacuum, and progesterone (2,2,4,6,6,17α,21,21,21-D9) is separated and purified by silica gel column chromatography, and then the eluent is dried under vacuum to obtain a pure product, which is stored in a refrigerator. The silica gel selected for silica gel column chromatography is 200-300 mesh, and the eluent is a mixture of petroleum ether and ethyl acetate, and the volume ratio of petroleum ether to ethyl acetate is 20:1-1:1.

[0020] The synthetic route of the present invention is as follows:

[0021]

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0023] (1) The present invention directly uses methoxyl anions generated online under electrochemical promotion as catalysts, which can not only achieve the purpose of catalyzing hydrogen-deuterium exchange, but also avoid the neutralization problem in the subsequent purification process when using strong acid or strong base conditions (if the acid or base is not removed, a large amount of product will be lost in the subsequent cleaning process). There is no need for neutralization and extraction, which effectively simplifies the subsequent purification process and can easily obtain pure progesterone (2,2,4,6,6,17α,21,21,21-D9).

[0024] (2) The present invention obtains progesterone (2,2,4,6,6,17α,21,21,21-D9) with high deuteration rate and high purity through an electrochemical synthesis method with simple operation, green, efficient, mild reaction process and good selectivity.

[0025] (3) The present invention does not require neutralization and extraction operations, which can save a large amount of deuterated reagents (neutralization must be performed during neutralization to ensure the deuterated rate of the product), reduce the risk of a decrease in the deuterated rate, greatly reduce the synthesis cost, and improve the synthesis time efficiency.

[0026] (4) The reactants in the present invention are cheap and readily available, the reaction process is simple and controllable, easy to operate, the product separation and purification are convenient, the yield is high, the deuteration rate is high, the purity is high, the cost is low, and it is easy to scale up the synthesis. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is the hydrogen nuclear magnetic resonance spectrum of the progesterone (2,2,4,6,6,17α,21,21,21-D9) product prepared in Example 1.

[0028] Figure 2 This is the mass spectrum of the progesterone (2,2,4,6,6,17α,21,21,21-D9) product prepared in Example 1. DETAILED DESCRIPTION

[0029] In order to better understand the present invention, the content of the present invention is further explained below in conjunction with the embodiments, but the present invention is not limited to the following embodiments.

[0030] Example 1

[0031] A method for synthesizing progesterone (2,2,4,6,6,17α,21,21,21-D9) by electrochemically promoted hydrogen-deuterium exchange, the specific process is as follows:

[0032] 94.3 mg (0.3 mmol) of progesterone and 65.9 mg (0.2 mmol) of electrolyte tetra-n-butylammonium tetrafluoroborate were added to a three-mouth reaction tube, a stirrer was added, a 1 cm*1 cm*0.3 mm carbon felt electrode was fixed to a 24# rubber stopper through an electrode clamp, and then fixed to the three-mouth reaction tube, the three ports of the three-mouth reaction tube were sealed with rubber stoppers, and the three-mouth reaction tube was replaced with nitrogen. Next, 0.5 mL of deuterated methanol-D4 (15.6 mmol) and 8 mL of tetrahydrofuran were added to the above three-mouth reaction tube as a reaction solvent, and then the reaction was carried out at a constant current of 5 mA for 5 hours. After the reaction is completed, deuterated methanol and tetrahydrofuran are dried under vacuum, and progesterone (2,2,4,6,6,17α,21,21,21-D9) is separated and purified by 200-300 mesh silica gel column chromatography, the eluent is a mixture of petroleum ether and ethyl acetate (the volume ratio of petroleum ether to ethyl acetate is 2:1), and the elution solvent is dried under vacuum to obtain the product progesterone (2,2,4,6,6,17α,21,21,21-D9). The theoretical yield of progesterone (2,2,4,6,6,17α,21,21,21-D9) is 91.6 mg, and the actual mass of the obtained product is 87.0 mg, the yield is 95%, the product purity is>98% (NMR), and the isotope deuteration rate is>85% (NMR).

[0033] The product progesterone (2,2,4,6,6,17α,21,21,21-D9) prepared in the example was characterized by hydrogen nuclear magnetic resonance spectrum and mass spectrum. Figure 1 As shown, progesterone (2,2,4,6,6,17α,21,21,21-D9) is synthesized from progesterone, and the chemical shifts of the H NMR spectrum change at 5.738ppm, 2.49-2.60ppm, 2.24-2.45ppm, and 2.130ppm. Figure 2 As shown, the molecular ion peak of progesterone in the mass spectrum is m / z = 316.46, the molecular ion peak of progesterone (2,2,4,6,6,17α,21,21,21-D9) is m / z = 325.29, and 322.27, 323.28, and 324.28 are isotope peaks related to the parent ion.

[0034] Example 2

[0035] A method for synthesizing progesterone (2,2,4,6,6,17α,21,21,21-D9) by electrochemically promoted hydrogen-deuterium exchange, the specific process is as follows:

[0036] 314.2 mg (1.0 mmol) of progesterone and 164.6 mg (0.5 mmol) of electrolyte tetrabutylammonium tetrafluoroborate were added to a three-mouth reaction tube, a stirrer was added, a 1 cm*1 cm*0.3 mm carbon felt electrode was fixed to a 24# rubber stopper through an electrode clamp, and then fixed to the three-mouth reaction tube, the three ports of the three-mouth reaction tube were sealed with rubber stoppers, and the three-mouth reaction tube was replaced with nitrogen. Next, 1.0 mL of deuterated methanol-D4 (31.2 mmol) was added to the above three-mouth reaction tube, and 10 mL of tetrahydrofuran was added as a reaction solvent, and the reaction was carried out at a constant current of 10 mA for 10 hours. After the reaction is completed, the deuterated methanol tetrahydrofuran is dried in vacuum, and progesterone (2,2,4,6,6,17α,21,21,21-D9) is separated and purified by 200-300 mesh silica gel column chromatography, the eluent is a mixture of petroleum ether and ethyl acetate (the volume ratio of petroleum ether to ethyl acetate is 2:1), and the elution solvent is dried in vacuum to obtain progesterone (2,2,4,6,6,17α,21,21,21-D9). Theoretically, the yield of progesterone (2,2,4,6,6,17α,21,21,21-D9) is 305.4 mg. In fact, the mass of the obtained product is 293.7 mg, the yield is 96%, the product purity is>98% (NMR), and the isotope deuteration rate is>85% (NMR).

[0037] The above is only a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several improvements and changes without departing from the creative concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A method for synthesizing progesterone (2,2,4,6,6,17α,21,21,21-D9) by electrochemically promoted hydrogen-deuterium exchange, characterized in that: Under a protective atmosphere, progesterone and deuterated methanol-D4 are used as raw materials, and electrolytes are added, and a constant current is applied in a reaction solvent to carry out a deuteration reaction; after the deuteration reaction is completed, progesterone (2,2,4,6,6,17α,21,21,21-D9) is obtained by separation and purification by silica gel column chromatography; the synthetic route is as follows: Wherein, the electrolyte is one or a mixture of any proportion of tetra-n-butylammonium tetrafluoroborate, tetraethylammonium tetrafluoroborate, tetra-n-butylammonium chloride, and tetra-n-butylammonium acetate; the concentration range of the electrolyte in the reaction solvent is 0.01-0.05 mmol / mL; The dosage ratio of deuterated methanol to progesterone is: 0.1-1 mL of deuterated methanol is added for every 0.3 mmol of progesterone; The reaction solvent is one of acetonitrile, N,N-dimethylformamide, tetrahydrofuran, and acetone, or a mixture of any proportions thereof; the dosage ratio of the reaction solvent to the progesterone is: 5-10 mL of the reaction solvent is added for every 0.3 mmol of progesterone, that is, the concentration range of the progesterone in the reaction solvent is 0.03-0.06 mmol / mL; The constant current is 5-20 mA, and the reaction time is 5-20 h.

2. The method according to claim 1, characterized in that The deuteration reaction is monitored by nuclear magnetic resonance spectroscopy and mass spectrometry. When the deuteration rate no longer increases, the reaction ends.

3. The method according to claim 1, characterized in that The electrode material used in the deuteration reaction is a carbon electrode; the silica gel selected for the silica gel column chromatography is 200-300 mesh, the eluent is a mixture of petroleum ether and ethyl acetate, and the volume ratio of petroleum ether to ethyl acetate is 20:1-1:

1.

4. The method according to any one of claims 1 to 3, characterized in that The steps include: (1) adding progesterone and electrolyte into a reaction vessel, wherein the concentration of the electrolyte in the reaction solvent is in the range of 0.01-0.05 mmol / mL, and inserting a carbon electrode as an electrode material; (2) under protective atmosphere and stirring conditions, adding deuterated methanol-D4 and a reaction solvent into the reaction vessel of step (1) and mixing them evenly, and then applying a constant current to carry out a deuterated reaction; (3) After the deuteration reaction is completed, the reaction solvent is dried under vacuum, and then the progesterone (2,2,4,6,6,17α,21,21,21-D9) is separated and purified by silica gel column chromatography. After drying, the pure progesterone (2,2,4,6,6,17α,21,21,21-D9) is obtained.

5. The method according to claim 4, characterized in that The silica gel column chromatography separation process is as follows: after the deuteration reaction is completed, the reaction solvent is dried in vacuum, and progesterone (2,2,4,6,6,17α,21,21,21-D9) is separated by silica gel column chromatography, and then the eluent is dried in vacuum, and the pure product can be obtained after drying and refrigerated storage.

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