CN113603618B

CN113603618B - Preparation method of creatine-D3

Info

Publication number: CN113603618B
Application number: CN202110790257.1A
Authority: CN
Inventors: 颜盛旺; 黄盛楼; 朱称古; 李刚
Original assignee: Wuxi Beita Pharmatech Co ltd
Current assignee: Wuxi Beita Pharmatech Co ltd
Priority date: 2021-07-13
Filing date: 2021-07-13
Publication date: 2023-06-09
Anticipated expiration: 2041-07-13
Also published as: CN113603618A

Abstract

The invention discloses a preparation method of creatine-D3, which comprises the following steps: (1) Carrying out amidation reaction on the compound SM-1 and the compound SM-2 to obtain a compound IM-1; (2) Carrying out esterification reaction on the compound IM-1 and the compound SM-3 to obtain a compound IM-2; (3) Carrying out methylation reaction on the compound IM-2 and a deuterated methylation reagent to obtain a compound IM-3; (4) Removing the protecting group of the compound IM-3 to obtain the creatine-D3. The preparation method has the advantages of cheap and easily obtained raw materials, mild reaction conditions, convenient operation and higher yield and purity of the obtained product.

Description

Preparation method of creatine-D3

Technical Field

The invention belongs to the field of isotope labeling substance preparation, and particularly relates to a preparation method of creatine-D3.

Background

Creatine is an amino acid synthesized by glycine, arginine and methionine in the liver, 98% of which is distributed in muscles, especially skeletal muscle, cardiac muscle and neuromuscular, and the erythrocytes of human body are rich in creatine. Serum creatine assay is widely used in serious muscle injury, polymyositis, dermatomyositis, progressive muscular atrophy, hyperthyroidism, muscular dystrophy, neuropathic muscular atrophy and other diseases.

The tandem mass spectrometry can accurately measure the concentration of creatine, and the method has good specificity and strong anti-interference capability, and is recognized as a gold standard for detecting human serum creatine. When the creatine content in serum is detected by tandem mass spectrometry, an isotope labeled internal standard creatine-D3 is sometimes needed, and a method for researching the creatine-D3 synthesis is necessary.

The Chinese patent application with publication number CN98110909A discloses a production process of high-purity creatine and its monohydrate, said production process adopts chloroacetic acid, methylamine and cyanamide aqueous solution to synthesize creatine, and the U.S. patent application also discloses a preparation method of creatine, and said method uses cyanamide and sodium sarcosinate or potassium sarcosinate to make reaction in water or in the mixture of water and organic solvent at 20-150 deg.C and pH value of 7-14 so as to obtain creatine. The method is adopted to obtain creatine, not creatine-D3, and the reaction yield is not high, for example, the yield of CN98110909A is only about 30-40%.

Disclosure of Invention

The invention provides a preparation method of creatine-D3, which has the advantages of cheap and easily obtained raw materials, mild reaction conditions, convenient operation and higher yield and purity of the obtained product.

The technical scheme of the invention is as follows:

a method for preparing creatine-D3, comprising the steps of:

(1) Carrying out amidation reaction on the compound SM-1 and the compound SM-2 to obtain a compound IM-1;

(2) Carrying out esterification reaction on the compound IM-1 and the compound SM-3 to obtain a compound IM-2;

(3) Carrying out methylation reaction on the compound IM-2 and a deuterated methylation reagent to obtain a compound IM-3;

(4) Removing protecting groups from the compound IM-3 to obtain the creatine-D3;

the reaction formula is as follows:

in the step (3), the deuterated methylation reagent is one or more of methyl iodide-D3, dimethyl sulfate-D6 and dimethyl carbonate-D6, and preferably, the deuterated methylation reagent is methyl iodide-D3.

Preferably, in the step (1), the amidation reaction is performed under the action of an inorganic base, and the inorganic base is one or more of potassium carbonate, sodium carbonate and cesium carbonate; as a further preferred, the inorganic base is potassium carbonate.

Preferably, in the step (1), the amidation reaction is performed in a mixed solvent of water and alcohol, wherein the alcohol is one or more of methanol, ethanol and isoamyl alcohol; as a further preferred, the alcohol is methanol. As a further preferred aspect, the volume ratio of methanol to water is 1:1-1.2, and the dosage ratio of methanol to compound SM-1 is 250-300 mL:1g, after the reaction, methanol and 85 to 95% of water were removed by concentration under reduced pressure, and the product was precipitated.

Preferably, in the step (2), the esterification reaction is performed under the action of an organic amine, and the organic amine is one or more of triethylamine, diisopropylethylamine and DMAP.

Preferably, in step (2), the esterification reaction is performed in DMF or DMSO.

Preferably, in step (3), the methylation reaction is performed in a base and a solvent;

the alkali is potassium carbonate, sodium hydroxide, potassium hydroxide or lithium hydroxide;

the solvent is DMF.

Preferably, in the step (3), the deuterated methylation reagent is added in a dropwise manner, and the dropwise addition temperature is-5 ℃.

Preferably, in the step (3), after the completion of the dropwise addition, the reaction is continued at room temperature for 12 to 24 hours.

Preferably, in step (4), the removal of the protecting group is performed under the action of palladium on carbon and hydrogen.

Preferably, in the step (4), the solvent used for removing the protecting group is methanol or ethanol.

Preferably, in step (4), the reaction temperature is 40 to 50 ℃.

Preferably, in the step (4), after the reaction is finished, the filter cake is filtered while the filter cake is hot, and the filter cake is washed with hot methanol, and the solvent is removed to obtain a product.

Compared with the prior art, the invention has the beneficial effects that:

(1) The invention avoids using complex or difficultly available marked compounds as the initial raw materials, and directly uses the marked methyl iodide-D3 which is easy to obtain in the market as the initial raw materials, so that the synthesis cost of creatine is greatly reduced;

(2) The creatine-D3 synthesized by the method can fill the domestic blank and is beneficial to meeting the huge demands of domestic and international markets;

(3) The method has mild reaction conditions, basically realizes the maximization of obtaining the high-purity creatine-D3, and directly synthesizes the creatine-D3 by one step, thereby greatly shortening the reaction time and the cost.

Detailed Description

Example 1

The reaction formula is as follows:

the preparation method comprises the following steps:

(1) Synthesis of IM-1: SM-1 (1.17 g,10mmol,1.0 eq), water 300ml, methanol 300ml, potassium carbonate (4.14 g,30mmol,3 eq) were added into a 1L single-neck flask, the temperature was reduced to 0 ℃ after dissolution, SM-2 (2.05 g,12mmol,1.2 eq) was added dropwise after natural warming to room temperature, the reaction was carried out overnight at room temperature, HPLC detection was completed, methanol and most of the water (20-30 ml of water remained) were removed under reduced pressure, the temperature was reduced to 0 ℃ and stirred for 1 hour, the filter cake was filtered and washed with cold water and ethyl acetate respectively, and the filter cake was dried to obtain IM-11.95g, (yield 77.68%).

(2) Synthesis of IM-2: to a 100ml single-necked flask, IM-1 (1.95 g,7.77mmol,1.0 eq), DMF (20 ml), triethylamine (2.36 g,23.31mmol,3.0 eq) were added dropwise SM-3 (1.98 g,11.66mmol,1.5 eq), the addition was completed naturally and warmed to room temperature, the reaction was carried out overnight at room temperature, and HPLC detection was completed. To the reaction mixture was added 200ml of water, and the mixture was extracted with 50ml of ethyl acetate X3, concentrated, and subjected to column chromatography (PE: EA=3:1) to obtain 2.13g (yield 80.35%) of IM-2.

(3) Synthesis of IM-3: to a 100ml single-necked flask, IM-2 (2.13 g,6.24mmol,1.2 eq), DMF (20 ml), potassium carbonate (2.15 g,15.6mmol,3.0 eq) were added dropwise methyl iodide-D3 (764 mg,5.2mmol,1.0 eq) (99.5 atom% D), the mixture was warmed to room temperature naturally, reacted overnight at room temperature, and the HPLC detection was completed. 200ml of water was added to the reaction mixture, which was extracted with 50ml of ethyl acetate X3, concentrated, and column-chromatographed (PE: EA=4:1) to give 1.35g (99 atom% D or more) of IM-3, and the content was 99.5% (yield 72.48%) by HPLC.

(4) Synthesis of creatine-D3: a100 ml single-necked flask was charged with IM-3 (1.35 g,3.77mmol,1 eq), methanol (40 ml), palladium on carbon (5%) 80mg, hydrogen substitution 5 times, hydrogen balloon reaction overnight at 45℃and after completion of HPLC detection, filtration while hot and washing of the filter cake with 100ml of hot methanol gave 452mg (. Gtoreq.99atom% D) and a content of 99.0% by HPLC detection (yield 89.4%).

Example 2

The other steps are the same as in example 1, and step (3) is replaced with the following steps:

synthesis of IM-3: to a 100ml single-necked flask, IM-2 (2.13 g,6.24mmol,1.2 eq), DMF (20 ml), sodium hydroxide (264 mg,15.6mmol,3.0 eq) were added dropwise methyl iodide-D3 (764 mg,5.2mmol,1.0 eq) (99.5 atom% D), the mixture was warmed to room temperature naturally, reacted overnight at room temperature, and the reaction was completed by HPLC detection. 200ml of water was added to the reaction mixture, which was extracted with 50ml of ethyl acetate X3, concentrated, and column-chromatographed (PE: EA=4:1) to give 0.86g (99% D or more) of IM-3, with a content of 97.3% (yield 46.19%) detected by HPLC.

Claims

1. A method for preparing creatine-D3, comprising the steps of:

the reaction formula is as follows:

in step (3), the deuterated methylation reagent is methyl iodide-D3;

in step (3), the methylation reaction is carried out in a base and a solvent;

the solvent is DMF;

in the step (3), the deuterated methylation reagent is added in a dropwise adding mode, and the dropwise adding temperature is-5 ℃;

in the step (3), after the dripping is completed, continuing to react at room temperature for 12-24 hours;

in the step (4), the protecting group is removed under the action of palladium-carbon and hydrogen.

2. The method for producing creatine-D3 according to claim 1, wherein in the step (1), the amidation reaction is performed under the action of an inorganic base selected from one or more of potassium carbonate, sodium carbonate and cesium carbonate.

3. The method for producing creatine-D3 according to claim 1, wherein in the step (1), the amidation reaction is performed in a mixed solvent of water and alcohol, and the alcohol is one or more of methanol, ethanol and isoamyl alcohol.

4. The method for preparing creatine-D3 according to claim 1, wherein in the step (2), the esterification reaction is performed under the action of an organic amine, and the organic amine is one or more of triethylamine, diisopropylethylamine and DMAP.

5. The method for producing creatine-D3 according to claim 1, wherein in the step (2), the esterification reaction is performed in DMF or DMSO.

6. The method for producing creatine-D3 according to claim 1, wherein the solvent used for removing the protecting group in step (4) is methanol or ethanol.