Method for synthesizing < 13 > C-pyruvic acid

Abstract

The invention provides a method for synthesizing < 13 > C-pyruvic acid, and relates to the field of isotope labeling medicines. The method comprises the following steps: reacting an isopropenyl Grignard reagent with 13CO2 in an inert atmosphere to obtain a first reaction product; carrying out quenching reaction on the first reaction product and acid to obtain a quenched reactant; carrying out liquid separation, extraction, drying and spin-drying, and reduced pressure distillation on the quenched reactant to obtain a purified organic phase; in an ozone environment, the purified organic phase and a reducing agent are subjected to an ozonization reaction to obtain a solid-liquid mixture; carrying out solid-liquid separation and molecular distillation on the solid-liquid mixture to obtain < 13 > C-pyruvic acid; the reducing agent comprises hexyl sulfide and / or sodium hydrogen sulfite. The method is good in purification effect and high in recovery rate, hexyl sulfide and sodium hydrogen sulfite are used as reducing agents, and by-products are solid and can be removed after suction filtration.

Description

Technical Field

[0001] The present invention relates to the field of isotope-labeled drugs, and in particular to a method for synthesizing 13 C-pyruvate method. Background Art

[0002] Pyruvate is a key branch point in many metabolic pathways in the body. Magnetic resonance imaging can detect metabolic processes in the body in a non-invasive, real-time, rapid and high-resolution manner. However, 13 The natural abundance and magnetic gyrophoresis ratio of C are very low, resulting in extremely low magnetic resonance signals of pyruvate, which limits its clinical application. 13 C]pyruvate and hyperpolarizing it can enhance the magnetic resonance signal by more than 10,000 times.

[0003] synthesis 13 The methods for preparing pyruvic acid mainly include a two-step method (CN116947622, ​​a method for synthesizing a pyruvic acid marker by a two-step method) and a one-pot method (CN116947621, a method for synthesizing a pyruvic acid marker by a one-pot method). The two methods have short synthesis routes and high yields. In the two-step method, methacrylic acid generated by the reaction of isopropenylmagnesium bromide and carbon dioxide is purified by extraction, then ozone is introduced to cause ozonation, and finally pyruvic acid is reduced; while in the one-step method, after the crude methacrylic acid product is generated, ozone is directly introduced to cause ozonation without any post-treatment, and finally pyruvic acid is reduced.

[0004] The existing two-step method for synthesizing pyruvic acid has poor purification effect and large loss, and the by-products produced during the reaction are difficult to remove. Summary of the invention

[0005] The purpose of this application is to provide a synthetic 13 C-pyruvic acid method to solve the above problems.

[0006] To achieve the above objectives, the present application provides a synthetic 13 C-pyruvate method, comprising:

[0007] Under an inert atmosphere, the isopropenyl Grignard reagent and 13 CO 2 Performing a first mixing and obtaining a first reaction product through a first reaction;

[0008] The first reaction product and the acid are mixed for a second time, and subjected to a quenching reaction to obtain a quenched reactant;

[0009] The quenched reactant is separated to obtain a separated organic phase and an aqueous phase, the aqueous phase and the extractant are thirdly mixed, and extracted to obtain an extracted organic phase, and the separated organic phase and the extracted organic phase are combined to obtain an organic phase to be dried;

[0010] The organic phase to be dried and the desiccant are mixed for the fourth time to obtain a dried organic phase;

[0011] The dried organic phase is spin-dried and distilled under reduced pressure to obtain a purified organic phase;

[0012] In an ozone environment, the purified organic phase and the reducing agent are mixed for a fifth time to obtain a solid-liquid mixture through an ozonation reaction;

[0013] The solid-liquid mixture is subjected to solid-liquid separation to obtain a filtrate;

[0014] The filtrate is molecularly distilled to obtain 13 C-pyruvate;

[0015] The reducing agent includes hexyl sulfide and / or sodium bisulfite.

[0016] Optionally, the synthesis 13 The method of C-pyruvic acid satisfies at least one of the following conditions:

[0017] A. the isopropenyl Grignard reagent comprises isopropenyl magnesium bromide;

[0018] B. the isopropenyl Grignard reagent and the 13 CO 2 The molar ratio is (1.1-1.3):1;

[0019] C. The temperature of the first reaction is -80°C to -70°C, and the time is 2h-3h.

[0020] Optionally, the acid comprises hydrochloric acid.

[0021] Optionally, the synthesis 13 The method of C-pyruvic acid satisfies at least one of the following conditions:

[0022] A. the pH value of the quenching reaction is 1-3;

[0023] B. The quenching reaction is carried out at a temperature of -10°C to room temperature and for a time of 1 h to 2 h.

[0024] Optionally, the synthesis 13 The method of C-pyruvic acid satisfies at least one of the following conditions:

[0025] A. the extractant comprises one or more of DCM, dichloromethane and ethyl acetate;

[0026] B. The volume ratio of the aqueous phase to the extractant is (0.9-1):1;

[0027] C. The extraction is performed 2 to 3 times.

[0028] Optionally, the synthesis 13 The method of C-pyruvic acid satisfies at least one of the following conditions:

[0029] A. The desiccant includes anhydrous magnesium sulfate and / or anhydrous sodium sulfate;

[0030] B. The liquid-to-solid ratio of the organic phase to be dried and the desiccant is (50 mL-100 mL): 1 g.

[0031] Optionally, the temperature of the reduced pressure distillation is 62° C.-66° C., and the pressure is less than or equal to 20 mb.

[0032] Optionally, the molar ratio of the organic phase to the reducing agent is 1:(0.9-1.1).

[0033] Optionally, the temperature of the ozonation reaction is -80°C to -50°C.

[0034] Optionally, the temperature of the molecular distillation is 66°C-70°C.

[0035] Compared with the prior art, the beneficial effects of this application include:

[0036] The synthesis provided in this application 13 C-pyruvic acid, in the purification 13 In the step of C-methylacrylic acid, the purification effect is good and the recovery rate is high by the method of drying and reduced pressure distillation after extraction; 13 After C-methyl acrylic acid and ozone undergo ozonation reaction, hexyl sulfide and sodium bisulfite are used as reducing agents, and the by-product is solid, which can be removed by filtration. The filtrate can be molecularly distilled to obtain a product with a purity and abundance greater than 99%. 13 C-pyruvic acid product with high yield and recovery rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope of the present application.

[0038] Figure 1 Prepared in Example 1 13 HPLC test chart of C-methacrylic acid;

[0039] Figure 2 Prepared in Example 1 13 C-methacrylic acid 1 H NMR spectra;

[0040] Figure 3 Prepared in Example 1 13 HPLC test chart of C-pyruvic acid;

[0041] Figure 4 Prepared in Example 1 13 C-pyruvic acid 1 H NMR spectra;

[0042] Figure 5 Prepared in Example 1 13 HRMS test chart of C-pyruvate. DETAILED DESCRIPTION

[0043] As used herein:

[0044] "Prepared from" is synonymous with "comprising." As used herein, the terms "comprising," "including," "having," "containing," or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a composition, process, method, article, or apparatus that comprises the listed elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, process, method, article, or apparatus.

[0045] The conjunction "consisting of excludes any unspecified element, step, or component. If used in a claim, this phrase renders the claim closed-ended so that it does not include materials other than those described, except for conventional impurities associated therewith. When the phrase "consisting of" appears in a clause of the body of a claim rather than immediately following the subject matter, it limits only the elements described in that clause; other elements are not excluded from the claim as a whole.

[0046] When an amount, concentration, or other value or parameter is expressed as a range, a preferred range, or a range defined by a series of upper preferred values ​​and lower preferred values, this should be understood as specifically disclosing all ranges formed by any pairing of any range upper limit or preferred value with any range lower limit or preferred value, regardless of whether the range is disclosed separately. For example, when a range of "1 to 5" is disclosed, the described range should be interpreted as including ranges "1 to 4", "1 to 3", "1 to 2", "1 to 2 and 4 to 5", "1 to 3 and 5", etc. When a numerical range is described in this article, unless otherwise stated, the range is intended to include its end values ​​and all integers and fractions within the range.

[0047] In these examples, parts and percentages are by mass unless otherwise indicated.

[0048] "Parts by mass" refers to the basic unit of measurement for expressing the mass ratio of multiple components. 1 part can represent any unit mass, such as 1g or 2.689g. If we say that the mass of component A is a parts and the mass of component B is b parts, it means the ratio of the mass of component A to the mass of component B is a:b. Alternatively, it means that the mass of component A is aK and the mass of component B is bK (K is an arbitrary number, indicating a multiple factor). It should not be misunderstood that, unlike the mass parts, the sum of the mass of all components is not limited to 100 parts.

[0049] "And / or" is used to indicate that one or both of the stated situations may occur, for example, A and / or B includes (A and B) and (A or B).

[0050] The present application provides a synthetic 13 C-pyruvate method, comprising:

[0051] Under an inert atmosphere, the isopropenyl Grignard reagent and 13 CO 2 Performing a first mixing and obtaining a first reaction product through a first reaction;

[0052] The first reaction product and the acid are mixed for a second time, and subjected to a quenching reaction to obtain a quenched reactant;

[0053] The quenched reactant is separated to obtain a separated organic phase and an aqueous phase, the aqueous phase and the extractant are thirdly mixed, and extracted to obtain an extracted organic phase, and the separated organic phase and the extracted organic phase are combined to obtain an organic phase to be dried;

[0054] The organic phase to be dried and the desiccant are mixed for the fourth time to obtain a dried organic phase;

[0055] The dried organic phase is spin-dried and distilled under reduced pressure to obtain a purified organic phase;

[0056] In an ozone environment, the purified organic phase and the reducing agent are mixed for a fifth time to obtain a solid-liquid mixture through an ozonation reaction;

[0057] The solid-liquid mixture is subjected to solid-liquid separation to obtain a filtrate;

[0058] The filtrate is molecularly distilled to obtain 13 C-pyruvate;

[0059] The reducing agent includes hexyl sulfide and / or sodium bisulfite.

[0060] It should be noted that hexyl sulfide is a liquid with a boiling point of 230°C. The dihexyl sulfoxide generated after oxidation is a solid and can be removed by filtration. However, pyruvic acid and hexyl sulfide have poor solubility and a large difference in boiling points. Therefore, pyruvic acid and hexyl sulfide can be completely separated after distillation, and the purity can reach more than 99%; sodium bisulfite and its oxidation product sodium bisulfate are both solids. After distillation, pyruvic acid, sodium bisulfite and its oxidation product sodium bisulfate can be completely separated.

[0061] Preferably, the yield using hexyl sulfide as a reducing agent is higher than that of sodium bisulfite.

[0062] In some embodiments, the specific reaction process is as follows:

[0063]

[0064] That is, isopropenylmagnesium bromide and 13 CO 2 Perform the first mixing to obtain 13 C-Methacrylmagnesium bromide, 13 C-methyl propylene magnesium bromide is hydrolyzed under acidic conditions to obtain 13 C-methacrylic acid, 13 C-methacrylic acid reacts with ozone to generate an ozonated intermediate, which is then reduced by a reducing agent, hexyl sulfide, to obtain 13 C-pyruvate.

[0065] In some embodiments, the synthesis 13 The method of C-pyruvic acid satisfies at least one of the following conditions:

[0066] A. the isopropenyl Grignard reagent comprises isopropenyl magnesium bromide;

[0067] B. the isopropenyl Grignard reagent and the 13 CO 2 The molar ratio is (1.1-1.3):1;

[0068] Optionally, isopropenyl Grignard reagent and 13 CO 2 The molar ratio can be any value between 1.1:1, 1.2:1, 1.3:1 or (1.1-1.3):1;

[0069] C. The temperature of the first reaction is -80°C to -70°C, and the time is 2h-3h.

[0070] Optionally, the temperature of the first reaction can be -80°C, -79°C, -78°C, -77°C, -76°C, -75°C, -74°C, -73°C, -72°C, -71°C, -70°C or any value between -80°C and -70°C, and the time can be 2h, 2.5h, 3h or any value between 2h and 3h.

[0071] In some embodiments, the acid comprises hydrochloric acid.

[0072] In some embodiments, the synthesis 13 The method of C-pyruvic acid satisfies at least one of the following conditions:

[0073] A. the pH value of the quenching reaction is 1-3;

[0074] Optionally, the pH value of the quenching reaction can be 1, 2, 3 or any value between 1 and 3;

[0075] B. The quenching reaction is carried out at a temperature of -10°C to room temperature and for a time of 1 h to 2 h.

[0076] Optionally, the temperature of the quenching reaction can be -10°C, -5°C, 0°C, 5°C, 10°C, 15°C, 20°C, 25°C or any value between -10°C and room temperature, and the time can be 1h, 1.5h, 2h or any value between 1h-2h.

[0077] In some embodiments, the synthesis 13 The method of C-pyruvic acid satisfies at least one of the following conditions:

[0078] A. the extractant comprises one or more of DCM, dichloromethane and ethyl acetate;

[0079] B. The volume ratio of the aqueous phase to the extractant is (0.9-1):1;

[0080] Optionally, the volume ratio of the aqueous phase to the extractant may be 0.9:1, 0.95:1, 1:1 or any value between (0.9-1):1;

[0081] C. The extraction is performed 2 to 3 times.

[0082] Optionally, the extraction may be performed 2 or 3 times.

[0083] In some embodiments, the synthesis 13 The method of C-pyruvic acid satisfies at least one of the following conditions:

[0084] A. The desiccant includes anhydrous magnesium sulfate and / or anhydrous sodium sulfate;

[0085] It should be noted that the desiccant is used to remove the residual trace water in the organic phase obtained after separation and extraction;

[0086] B. The liquid-to-solid ratio of the organic phase to be dried and the desiccant is (50 mL-100 mL): 1 g.

[0087] Optionally, the liquid-to-solid ratio of the organic phase to be dried and the desiccant can be any value between 50 mL:1 g, 60 mL:1 g, 70 mL:1 g, 80 mL:1 g, 90 mL:1 g, 100 mL:1 g or (50 mL-100 mL):1 g.

[0088] In some embodiments, the temperature of the reduced pressure distillation is 62° C.-66° C., and the pressure is less than or equal to 20 mb.

[0089] Optionally, the temperature of the reduced pressure distillation can be 62°C, 63°C, 64°C, 65°C, 66°C or any value between 62°C and 66°C, and the pressure can be 0.1mb, 1mb, 5mb, 10mb, 15mb, 20mb or any value less than or equal to 20mb.

[0090] It should be noted that the vacuum distillation can be stopped when all the reaction solution to be vacuum distilled has been evaporated.

[0091] It should also be noted that vacuum distillation can remove impurities such as residual solvents and by-products, and 13 The purity of C-methacrylic acid is improved. In some embodiments, 13 The purity of C-methacrylic acid can be purified from 70% to more than 99%.

[0092] In some embodiments, the molar ratio of the organic phase to the reducing agent is 1:(0.9-1.1).

[0093] Optionally, the molar ratio of the organic phase to the reducing agent can be 0.9:1, 1:1, 1.1:1 or any value between (0.9-1.1):1.

[0094] In some embodiments, the temperature of the ozonation reaction is -80°C to -50°C.

[0095] Optionally, the temperature of the ozonation reaction can be -80°C, -75°C, -70°C, -65°C, -60°C, -55°C, -50°C or any value between -80°C and -50°C.

[0096] It should be noted that the ozonation reaction was stopped when the reaction solution turned blue.

[0097] In some embodiments, the molecular distillation temperature is 66°C-70°C.

[0098] Optionally, the temperature of molecular distillation can be 66°C, 67°C, 68°C, 69°C, 70°C or any value between 66°C and 70°C.

[0099] It should be noted that the molecular distillation can be stopped when all the reaction solution to be molecularly distilled has been evaporated.

[0100] The embodiments of the present application will be described in detail below in conjunction with specific examples, but it will be appreciated by those skilled in the art that the following examples are only used to illustrate the present application and should not be considered as limiting the scope of the present application. If specific conditions are not specified in the examples, they are carried out according to normal conditions or the conditions recommended by the manufacturer. If the manufacturer is not specified for the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0101] Example 1

[0102] This embodiment provides a synthetic 13 C-pyruvate method, comprising:

[0103] S1: Take a dried 2L three-necked round-bottom flask, add a magnet, connect a three-way valve, a rubber stopper and a thermometer, replace the air in the three-necked round-bottom flask with nitrogen, then pump 1.2L of isopropenylmagnesium bromide Grignard reagent (1M in THF, 1mol, 1.2eq) into the three-necked round-bottom flask through a double-row needle, put it in a condenser and cool it to -70°C, connect the carbon dioxide cylinder to a gas flow meter, connect the gas flow meter to a long needle and insert it into the three-necked round-bottom flask, then open the cylinder, set the flow rate to 600mL / min, ventilate a total of 22.4L (1mol, 1eq), stop venting, and continue stirring at -70°C for 2h;

[0104] S2: After 2 hours, water was added dropwise to quench the reaction. After the addition was completed, the cold bath was removed and the reaction mixture was stirred for 1 hour. The reaction mixture was naturally restored to room temperature. Then, 6M hydrochloric acid was added dropwise to adjust the pH to 2. The reaction mixture was separated and the organic phase was collected. The aqueous phase was extracted with an equal volume of DCM for 3 times. The organic phases were combined, dried with anhydrous magnesium sulfate and then filtered. The liquid-to-solid ratio of the organic phase to the desiccant was (50 mL-100 mL): 1 g. The filtrate was dried by rotary evaporation to obtain a crude product. The crude product was subjected to reduced pressure distillation and the 62°C-66°C fraction was collected to obtain 13 C-Methacrylic acid pure product is a colorless clear liquid;

[0105] S3: 43.5 g (0.5 mol, 1 eq) of distilled methacrylic acid was transferred to a 1 L single-mouth round-bottom flask, a magnetic rod was added, and DCM was added, cooled to -70 ° C, the oxygen cylinder was connected to the ozone generator, the ozone generator was connected to the ventilation tube and inserted into the flask, the ozone switch was turned on to start the reaction, and the reaction was completed until the reaction solution changed from colorless to blue, and then the ozone generator was turned off, and oxygen was introduced for 5 min to remove excess ozone; then 101.2 g of hexyl sulfide (0.5 mol, 1 eq) was added dropwise to the flask, and the temperature was naturally raised to 40 ° C and refluxed for 4 h after the addition was completed. After the reaction was completed, the filtrate was filtered and the filtrate was collected. The crude product was subjected to molecular distillation, and the 66 ° C-70 ° C fraction was collected to obtain 13 Pure C-pyruvic acid is a light yellow oily liquid.

[0106] Should 13 HPLC test of C-methacrylic acid Figure 1 As shown, the peak appears at about 15 minutes;

[0107] Should 13 C-methacrylic acid 1 H NMR test Figure 2 As shown in the figure, 13 C-methacrylic acid 1 H NMR spectrum (CDCl 3 , 400MHz) δ11.93 (s, COOH, 1H), 6.23 (s, CH, 1H), 5.70 (s, CH, 1H), 1.95 (s, CH 3 , 3H).

[0108] Should 13 HPLC test of C-pyruvic acid Figure 3 As shown, the peak appears at about 2.7 min;

[0109] Should 13 C-pyruvic acid 1 H NMR test Figure 4 As shown in the figure, 13 C-pyruvic acid 1 H NMR spectrum (CDCl 3 , 400MHz) δ9.44 (s, COOH, 1H), 2.50 (s, CH 3 , 3H).

[0110] Should 13 HRMS test of C-pyruvate Figure 5 As shown, 13 The molecular weight of C-pyruvic acid is 89, and the M-1 peak appears in the negative ion mode, which proves that the pyruvic acid prepared in this example is 13C-pyruvate.

[0111] Example 2

[0112] This embodiment provides a synthetic 13 The method for preparing C-pyruvic acid is different from that of Example 1 in that the amount of isopropenylmagnesium bromide Grignard reagent (1 mol, 1 eq) added in this example is 1 L, and the amount of carbon dioxide (1.2 mol, 1.2 eq) added is 26.88 L.

[0113] Example 3

[0114] This embodiment provides a synthetic 13 The method for preparing C-pyruvic acid is different from that of Example 2 in that: in step S2, water is first added for quenching, and then 6M hydrochloric acid is added for acid adjustment.

[0115] Example 4

[0116] This embodiment provides a synthetic 13 The method for preparing C-pyruvic acid is different from that of Example 2 in that after stopping aeration in step S1, stirring is continued at -70°C for 14h.

[0117] Example 5

[0118] This embodiment provides a synthetic 13 The method for preparing C-pyruvic acid is different from that of Example 2 in that: Step S1 is to place the mixture in a condenser and cool it to -50°C, stop ventilation, and continue stirring at -50°C for 2h.

[0119] Example 6

[0120] This embodiment provides a synthetic 13 The method for preparing C-pyruvic acid is different from that of Example 1 in that in this example, when performing step S3, the reaction is performed by cooling to -50°C and introducing ozone at -50°C.

[0121] Example 7

[0122] This embodiment provides a synthetic 13 The method for preparing C-pyruvic acid is different from that of Example 1 in that in this example, after the addition of hexyl sulfide is completed, the temperature is raised to room temperature and stirred for 4 hours.

[0123] Comparative Example 1

[0124] This comparative example provides a synthetic 13 The method for preparing C-pyruvic acid is different from that of Example 1 in that in this comparative example, when performing step S2, no vacuum distillation is performed, and the spin-dried filtrate obtained is directly transferred to a 1L single-mouth round-bottom flask for ozonation reaction.

[0125] Comparative Example 2

[0126] This comparative example provides a synthetic 13 The method of preparing C-pyruvic acid is different from that of Example 1 in that the reducing agent in this comparative example is dimethyl sulfide.

[0127] Comparative Example 3

[0128] This comparative example provides a synthetic 13 The method of preparing C-pyruvic acid is different from that of Example 1 in that the reducing agent in this comparative example is triphenylphosphine.

[0129] The above examples and comparative examples prepared 13 C-methacrylic acid and 13 The C-pyruvic acid was weighed, the content was measured in the liquid phase, and the recovery rate was calculated. The specific results are shown in Table 1.

[0130] The specific method for liquid phase content measurement is: 13 The HPLC chromatogram of C-methylacrylic acid on a C18 column with a mobile phase of 0.02 M potassium dihydrogen phosphate: acetonitrile in a ratio of 90:10 was compared with the peak area of ​​the reference substance and the content was calculated using the external standard method.

[0131] Table 1 Test results

[0132]

[0133] From the above examples and comparative examples, it can be seen that Example 2 and Example 5 prove that the reaction temperature has the greatest impact on the yield, and the yield decreases significantly when the temperature increases.

[0134] Example 1 and Comparative Example 1 prove that the purity of methacrylic acid after reduced pressure distillation is higher, less impurities are introduced in the next reaction, and the yield is higher.

[0135] Example 1 and Comparative Example 2 prove that the crude pyruvic acid obtained after the reduction of hexyl sulfide can be purified to more than 99% by molecular distillation, while the crude pyruvic acid obtained after the reduction of methyl sulfide cannot be purified by molecular distillation. Methyl sulfide is a liquid with a boiling point of 38°C, and the dimethyl sulfoxide generated after oxidation is a liquid with a boiling point of 189°C; pyruvic acid is a liquid with a boiling point of 165°C and has good solubility in dimethyl sulfoxide. Therefore, although distillation can remove methyl sulfide with a large difference in boiling point, it cannot remove dimethyl sulfoxide with a small difference in boiling point and good solubility.

[0136] Example 1 and Comparative Example 3 demonstrate that when triphenylphosphine is used as a reducing agent, 13 The crude yield of C-pyruvic acid was only 67.45%.

[0137] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

[0138] In addition, those skilled in the art will appreciate that, although some embodiments herein include certain features included in other embodiments but not other features, the combination of features of different embodiments is meant to be within the scope of the present application and form different embodiments. For example, in the above claims, any one of the claimed embodiments may be used in any combination. The information disclosed in this background technology section is intended only to deepen the understanding of the overall background technology of the present application and should not be regarded as an admission or in any form of implication that the information constitutes prior art known to those skilled in the art.

Claims

1. A synthesis 13 C-pyruvic acid method, characterized in that include: Under an inert atmosphere, the isopropenyl Grignard reagent and 13 CO2 is first mixed and first reacted to obtain a first reaction product; The first reaction product and the acid are mixed for a second time, and subjected to a quenching reaction to obtain a quenched reactant; The quenched reactant is separated to obtain a separated organic phase and an aqueous phase, the aqueous phase and the extractant are thirdly mixed, and extracted to obtain an extracted organic phase, and the separated organic phase and the extracted organic phase are combined to obtain an organic phase to be dried; The organic phase to be dried and the desiccant are mixed for the fourth time to obtain a dried organic phase; The dried organic phase is spin-dried and distilled under reduced pressure to obtain a purified organic phase; In an ozone environment, the purified organic phase and the reducing agent are mixed for a fifth time to obtain a solid-liquid mixture through an ozonation reaction; The solid-liquid mixture is subjected to solid-liquid separation to obtain a filtrate; The filtrate is molecularly distilled to obtain 13 C-pyruvate; The reducing agent includes hexyl sulfide and / or sodium bisulfite.

2. The synthesis according to claim 1 13 C-pyruvic acid method, characterized in that At least one of the following conditions is met: A. the isopropenyl Grignard reagent comprises isopropenyl magnesium bromide; B. the isopropenyl Grignard reagent and the 13 The molar ratio of CO2 is (1.1-1.3):1; C. The temperature of the first reaction is -80°C to -70°C, and the time is 2h-3h.

3. The synthesis according to claim 1 13 C-pyruvic acid method, characterized in that The acid includes hydrochloric acid.

4. The synthesis according to claim 1 13 C-pyruvic acid method, characterized in that At least one of the following conditions is met: A. the pH value of the quenching reaction is 1-3; B. The quenching reaction is carried out at a temperature of -10°C to room temperature and for a time of 1 h to 2 h.

5. The synthesis according to claim 1 13 C-pyruvic acid method, characterized in that At least one of the following conditions is met: A. the extractant comprises one or more of dichloromethane and ethyl acetate; B. The volume ratio of the aqueous phase to the extractant is (0.9-1):1; C. The extraction is performed 2 to 3 times.

6. The synthesis according to claim 1 13 C-pyruvic acid method, characterized in that At least one of the following conditions is met: A. The desiccant includes anhydrous magnesium sulfate and / or anhydrous sodium sulfate; B. The liquid-to-solid ratio of the organic phase to be dried and the desiccant is (50 mL-100 mL): 1 g.

7. The synthesis according to claim 1 13 C-pyruvic acid method, characterized in that The temperature of the reduced pressure distillation is 62° C.-66° C., and the pressure is less than or equal to 20 mb.

8. The synthesis according to claim 1 13 C-pyruvic acid method, characterized in that The molar ratio of the organic phase to the reducing agent is 1:(0.9-1).

9. The synthesis according to claim 1 13 C-pyruvic acid method, characterized in that The temperature of the ozonation reaction is -80°C to -50°C.

10. The synthesis according to any one of claims 1 to 9 13 C-pyruvic acid method, characterized in that The temperature of the molecular distillation is 66°C-70°C.

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