CN112209950A

CN112209950A - Vitamin B1Impurities and process for their preparation

Info

Publication number: CN112209950A
Application number: CN201910623376.0A
Authority: CN
Inventors: 白跃飞; 刘明; 孟德龙; 孙董军; 皮昌桥; 刘素娜; 周联波
Original assignee: NORTHEAST PHARMACEUTICAL GROUP CO Ltd
Current assignee: NORTHEAST PHARMACEUTICAL GROUP CO Ltd
Priority date: 2019-07-11
Filing date: 2019-07-11
Publication date: 2021-01-12

Abstract

The invention provides vitamin B₁Impurities and a preparation method thereof, belonging to the technical field of compounds. The vitamin B₁The impurity is a compound with a new structure, and is obtained by the reaction of vitamin B1 and inorganic acid. The compound has the characteristics of novel structure, wide application and the like, and the preparation method has the characteristics of easily obtained raw materials, low cost, simple operation steps, high yield and the like.

Description

Vitamin B1Impurities and process for their preparation

Technical Field

The invention belongs to the technical field of compounds, and particularly relates to vitamin B₁Impurities and a preparation method thereof.

Background

The vitamin B1 molecule is a quaternary ammonium salt formed by combining a methylene-linked substituted thiazole ring with a pyrimidine ring. Its chemical name is 4-methyl-3- [ (2-methyl-4-amino-5-pyrimidinyl) methyl chloride]-5- (2-hydroxyethyl) thiazolium hydrochloride, also known as vitamin B hydrochloride₁Hydrochloric acidVB₁Thiamine hydrochloride or thiamine, formula C₁₂H₁₇ClN₄OS · HCl, molecular weight 337.27, CAS: 67-03-8. The structural formula is as follows:

the first was 1912 Fengke (Funk) from rice bran, while the purer preparations were produced in 1927 by Jansen (Jansen) and Donnatt (Doanath). The crystals were separated from yeast in 1931 by Wendous (Windaus) and its collaborators. Williams (Williams) and Graevir (Grewe) demonstrated vitamin B independently of each other in 1936₁The structure of (1). Vitamin B was synthesized in the same year by Williams and Kleine (Cline) and by Andersag (Andersag) and West Phal₁And thus its structure is finally proved.

Vitamins are often referred to as "ten thousand" type products, in the sense that they are not only fixed components and indispensable nutrients in the animal's body, but also drugs for the treatment of vitamin deficiency and indispensable nutrients against other diseases. Wherein vitamin B₁Is mainly used in the fields of medicine and food, especially for vitamin B1 deficiency, has functions of maintaining normal glycometabolism and nerve conduction, and can be used for treating dyspepsia, beriberi, myasthenia, sensory disturbance, heart irregularity, poor appetite, asthma, neuritis, etc. The medical field successively discovers vitamin B₁There are a number of interesting health uses, including: frequent vitamin B supplement for middle-aged and elderly people₁Can prevent the Alzheimer disease (senile dementia) which has no effective treatment means at present in the medical field; daily supplement intake of vitamin B for hyperglycemia patients, glucose tolerance increase patients and diabetes patients₁The preparation can prevent atherosclerosis, thereby reducing incidence rate of fatal cardiovascular accidents such as apoplexy or myocardial infarction; frequent intake of vitamin B₁The composition is helpful for reducing the incidence rate of malignant tumors; preventing cataract, etc.

From vitamin B₁Has a hydrochloride-based structure, so that no matter what process is adopted to prepare vitamin B₁The final salifying synthesis process needs to be performed under the acidic condition of hydrochloric acid or HCl gas. The European pharmacopoeia (EP9.0) has already recorded vitamin B₁A to H in total of 8 impurity structures. In addition, CN103896935A discloses demethylated vitamin B₁And researching impurities of intermediates and finished products. According to the internationally recognized requirement for drug registration technology for human use, international harmonization (ICH) and european pharmacopoeia, the drug registration is subject to strict regulations on impurities in the drug. ICH claims reporters should summarize the actual and potential impurities that are most likely to be generated during the course of synthesis, purification and storage of drug substances, and if these impurities are not strictly controlled, they may have serious toxic side effects on the human body. The research on the visible impurities has great significance on the control of the product quality and the medication safety of people. Therefore, VB was further investigated₁The possible impurities are new problems to be solved at present.

Disclosure of Invention

The invention aims to provide a compound with a novel structure, a preparation method and application thereof, wherein the compound has the characteristics of novel structure, wide application and the like, and the preparation method has the characteristics of easily available raw materials, low cost, simple operation steps, high yield and the like.

The purpose of the invention is realized as follows: a compound represented by formula I or a salt thereof,

wherein R is₁And R₂Independently selected from C1 to C6 alkyl;

the alkyl of C1-C6 is selected from alkyl of C1-C4; the alkyl of C1 to C4 is selected from one of methyl, ethyl, propyl, isopropyl, cyclopropyl, butyl, isobutyl and cyclobutyl; the salt is selected from one of hydrochloride, hydrofluoride, hydrobromide, hydroiodide, phosphate, nitrate and sulfate.

A method for preparing a compound shown as a formula I and a salt thereof,

in the formula I, R₁And R₂Independently selected from the group consisting of C1 to C6, the process comprising the steps of: taking the salt of the compound shown in the formula II to react with inorganic acid,

obtaining a salt of the compound shown in the formula I; in the formula II, R₁And R₂Independently selected from C1 to C6 alkyl; the alkyl of C1-C6 is selected from alkyl of C1-C4; the alkyl of C1 to C4 is selected from one of methyl, ethyl, propyl, isopropyl, cyclopropyl, butyl, isobutyl and cyclobutyl; the salt is selected from one of hydrochloride, hydrofluoride, hydrobromide, hydroiodide, phosphate, nitrate and sulfate; the inorganic acid is selected from one of hydrochloric acid, hydrofluoric acid, hydrobromic acid, hydroiodic acid, phosphoric acid, nitric acid and sulfuric acid; the solvent for the reaction is water, the temperature for the reaction is 60-160 ℃, and the time for the reaction is 2-16 h; the method further comprises the step of concentrating the reaction solution after the reaction is finished to obtain a crude solid of the salt of the compound shown in the formula I, wherein the concentration is reduced pressure concentration, and the concentration temperature is 40-90 ℃; the method comprises the following steps of (1) before concentrating the reaction liquid, decoloring the reaction liquid, wherein a decoloring agent used for decoloring is activated carbon, the temperature of the reaction liquid is 40-50 ℃ when the decoloring agent is added, and the decoloring time is 0.1-1 hour; the molar ratio of the salt of the compound represented by the formula II to the inorganic acid is 1:1-10, preferably 1:2-6, more preferably 1: 3-4; the molar ratio of the salt of the compound shown in the formula II to the solvent water used in the reaction is 1:5-160, and the preferred molar ratio is 1: 10-50; the temperature of the reactionThe temperature is 60-130 ℃, the preferable reaction temperature is 90-110 ℃, the reaction time is 2-12 hours, and the preferable reaction time is 6-9 hours; the method also comprises the step of recrystallizing the crude solid of the salt of the compound shown in the formula I to obtain a finished product, wherein the solvent used for recrystallization is a mixed solvent of water and alcohol, the alcohol is selected from lower alcohol, and the lower alcohol is selected from one or more of methanol, ethanol, propanol, isopropanol, butanol and isobutanol; the molar ratio of the salt of the compound shown in the formula II to the solvent water used for recrystallization is 1:8-20, and the preferred molar ratio is 1: 10-15; in the solvent used for recrystallization, the weight ratio of water to alcohol is 1:2-7, and the preferable weight ratio is 1: 4-6; the temperature of the concentration is 45-70 ℃.

7. The preparation method of the compound shown in the formula I and the salt thereof according to claim 6, characterized in that the recrystallization method comprises the following steps: at a certain temperature, adding the crude solid of the salt of the compound shown in the formula I into water for dissolving, then dripping alcohol, cooling, filtering and drying; the temperature at a certain temperature is 45-65 ℃, and the preferred temperature is 50-60 ℃; the temperature for reducing the temperature is 15-35 ℃, and the preferable temperature is 20-30 ℃; the dissolution is carried out under the condition of stirring, and the temperature reduction is natural temperature reduction.

The compound shown in the formula I or the salt thereof is used as an antioxidant; the compound shown as the formula I or the salt thereof is used as an impurity reference substance; the compound shown in the formula I or the salt thereof is used as a raw material and/or an intermediate in organic synthesis reaction.

The key point of the invention lies in a kind of compound with new structure and its preparation method and use, its principle is: (1) the compound provided by the invention is a compound with a new parent nucleus structure; (2) the preparation method of the compound is simple, the raw materials are easy to obtain, the cost is low, and the yield is high; (3) the compound can react with hydrogen peroxide, so that the compound has reducibility and can be used as an antioxidant; (4) the compounds can be used as vitamin B₁And the like. (5) The compound can be used as raw material and/or intermediate in organic synthesis reactionThe compounds are useful for the preparation of novel or known compounds. (6) The recrystallization method has the advantages of simple and easily obtained solvent, low cost, mild recrystallization conditions and high yield.

Compared with the prior art, the compound with a new structure and the preparation method and the application thereof have the characteristics of novel structure of the compound parent nucleus, wide application, easily available raw materials, low cost, simple operation steps, high yield and the like, and can be widely applied to the fields of chemical industry, pharmacy and the like.

Drawings

FIG. 1 is an HPLC purity detection profile of vitamin B1 bulk drug of the present invention.

FIG. 2 is a HPLC purity detection profile of impurity I of the present invention.

FIG. 3 is a high resolution mass spectrum of impurity I in the present invention.

FIG. 4 shows the NMR spectrum of impurity I in the present invention.

FIG. 5 is a NMR carbon spectrum of impurity I in the present invention.

FIG. 6 is an IR spectrum of impurity I in the present invention.

FIG. 7 shows the mechanism of formation of impurity I by reaction in the present invention.

FIG. 8 is a TLC chart of impurity I before and after reaction in example IV of the present invention.

FIG. 9 is a TLC chart of impurity I before and after reaction in example V of the present invention.

FIG. 10 is a reaction equation for producing impurity I in the present invention.

Detailed Description

In order to further understand the present invention, the following detailed description will be made on the technical solutions provided by the present invention with reference to examples. It is to be understood that these examples are described merely to illustrate the features of the present invention in further detail, and not as limitations of the invention or of the scope of the claims appended hereto.

Example one

Step one, referring to Chinese pharmacopoeia (ChP2015) and EP9.0 vitamin B₁Checking chromatographic conditions for the relevant substances, and testing the vitamin B₁Samples, checked for HPLC purity, are shown in table 1 and figure 1. Hair-like deviceAt present, an impurity peak always exists, the relative retention time is 13.147, the purity is about 0.04%, the molecular weight of the impurity is inconsistent with the molecular weight of the impurity reported by pharmacopoeia and sold on the market, and in order to perfect the needs of the preparation process, quality research and registration declaration work, the impurity is deeply researched and named as impurity I (the sequence of recording the impurity according to EP 9.0).

TABLE 1 chromatographic Peak results

	Name (R)	Retention time	Area of	Peak height	% area
						1	3.407	43729	3110	0.03
2		4.293	81428	8473	0.05
						3	8.238	6445	726	0.00
4		13.147	55912	5404	0.04
						5	19.890	7545	661	0.00
6		23.257	11016	891	0.01
						7	29.775	158327936	3649440	99.77
8		31.846	8364	881	0.01
						9	34.436	121748	16053	0.08
10		34.794	8263	1125	0.01
						11	36.591	10292	1159	0.01
12		38.262	9227	914	0.01

Step two, in vitamin B₁In the process of technological research, the inventors unexpectedly found that the HPLC purity of the impurity I tends to be significantly increased if the reaction temperature of the acidic system for the last salt formation step is increased or the temperature of the post-treatment of the reaction solution is increased, so that we finally purify the impurity I by optimizing the reaction conditions and using a recrystallization method, wherein the purity detected by the HPLC method is 98.24% (area normalization), as shown in table 2 and fig. 2. The melting point of the impurity I is 282-284 ℃ through an analysis test (Decomp).

TABLE 2 chromatographic Peak results

And step three, determining the specific structural formula of the impurity I by adopting a High Resolution Mass Spectrometry (HRMS) as shown in figure 3, a nuclear magnetic resonance hydrogen spectrum as shown in figure 4, a carbon spectrum as shown in figure 5, an infrared spectrum as shown in figure 6 and the like. IR (KBr) delta 3385.5,2669.4,1716.2,1668.1,1639.0,1586.5,1551.5,1456.7,1394.3,1318.0,1257.7,1172.6,1126.5,1067.4,559.8cm^-1；HRMS：266.1069[M+H]⁺；¹H-NMR(MeOD，600MHz,δ:ppm)：2.620(s，3H)，2.692(s，3H)，3.123(t，2H，J＝5.4Hz)，3.806(t，2H，J＝5.4Hz)，5.585(s，2H)，8.434(s，1H)，10.098(s，1H)；¹C-NMR(MeOD，150MHz,δ:ppm)：165.6,161.0,158.8,145.3，143.9,136.9,119.7,61.3,50.7,30.8,19.1,12.2。

The chemical name of the hydrochloride of the impurity I is 2- (2, 7-dimethyl-5, 9 a-2H-pyrimidine [5,4-e ]]Thiazole 2,3-b][1,3]Oxazin-8-yl) ethanol hydrochloride of formula C₁₂H₁₅N₃O₂S.HCl, molecular weight 301.79, structural formula as follows:

step four, combining the structural formula of the impurity I and the generated reaction condition, and supposing that the reaction generation mechanism is probably vitamin B under the strong acid heating condition of hydrochloric acid₁Firstly, amino is removed from the pyrimidine ring part of the molecule, then, the carbon-nitrogen double bond of the thiazole ring and solvent water molecule are subjected to addition reaction, and finally, intramolecular ring closure is carried out to lose one molecule of water. The specific transition process is shown in fig. 7.

And step five, designing a synthetic route and preparing the impurity finished product. See example two and example three of this application for specific methods. When HPLC is measured, the relative retention time 13.147 of the peak position is the same as the peak time of the impurity I, and the High Resolution Mass Spectrum (HRMS), the nuclear magnetic resonance hydrogen spectrum, the carbon spectrum, the infrared structure characterization spectrogram and the like of the HPLC are consistent with the spectrogram of the qualitative impurity I structure.

Vitamin B of the invention₁The single impurity is structurally characterized, the forming process is deduced, a synthetic method is designed, and the impurity monomer is prepared and can be used for vitamin B₁Registration, quality research, process research and impurity preparation of raw material medicaments and preparations, and formulation and improvement of vitamin B by using the raw material medicaments and the preparations as impurity reference substances₁Provides effective data support for vitamin B₁Provides effective guarantee for clinical safe use.

Example two

33.7g (100.0mmol) of vitamin B₁Adding 33.3mL (400.0mmol) of concentrated hydrochloric acid into a 500mL single-mouth eggplant-shaped bottle, sleeving a reflux condenser tube, stirring, heating to the internal temperature of 90 ℃, reacting after 8 hours to obtain a reaction solution, adding 0.15g of activated carbon to decolor when the temperature is reduced to 45 ℃, continuously stirring for 0.5 hour, and directly filtering to remove the activated carbon to obtain a filtrate. Concentrating under reduced pressure at 45-70 ℃, and evaporating to remove water and HCl gas to obtain light yellow impurity I hydrochloride crude solid. And (3) adding the crude product into 21.6g of water at 50-60 ℃, stirring until the crude product is dissolved, then dripping 108.0g of absolute ethyl alcohol, naturally cooling to 20-30 ℃, filtering and drying to obtain 24.3g of white-like crystalline solid, namely an impurity I hydrochloride finished product, wherein the yield is 91.4%. It is easily soluble in water and methanol, slightly soluble in ethanol, insoluble in acetone, ethyl acetate and petroleum ether, 0.5g impurity I hydrochloride dissolvedThe pH was 1.52 in 10mL water. m.p.: 282-284 ℃; IR (KBr) delta 3385.5,2669.4,1716.2,1668.1,1639.0,1586.5,1551.5,1456.7,1394.3,1318.0,1257.7,1172.6,1126.5,1067.4,559.8cm^-1；HRMS：266.1069[M+H]⁺；¹H-NMR(MeOD，600MHz,δ:ppm)：2.620(s，3H)，2.692(s，3H)，3.123(t，2H，J＝5.4Hz)，3.806(t，2H，J＝5.4Hz)，5.585(s，2H)，8.434(s，1H)，10.098(s，1H)；¹C-NMR (MeOD, 150MHz,. delta.: ppm): 165.6,161.0,158.8,145.3, 143.9,136.9,119.7,61.3,50.7,30.8,19.1,12.2. The reaction equation is shown in FIG. 10.

EXAMPLE III

33.7g (100.0mmol) of vitamin B₁Adding 98.0g (300.0mmol) of 30% sulfuric acid into a 500mL single-opening eggplant-shaped bottle, sleeving a reflux condenser tube, stirring, heating to the internal temperature of 110 ℃, reacting after 10h to obtain a reaction solution, adding 0.25g of activated carbon to decolor when the temperature is reduced to 50 ℃, continuously stirring for 0.5h, and directly filtering to remove the activated carbon to obtain a filtrate. Concentrating under reduced pressure at 45-70 ℃, and removing water by evaporation to obtain a yellowish impurity I sulfate crude product solid. And (2) adding the crude product into 24.5g of water at 50-60 ℃, stirring until the crude product is dissolved, then dripping 122.5g of anhydrous methanol, naturally cooling to 20-30 ℃, filtering and drying to obtain 24.9g of a white-like crystalline solid, namely 1/2 sulfate finished product of the impurity I, wherein the yield is 93.8%. m.p.: 267-269 ℃ (decomp); IR (KBr) delta 3385.5,2669.4,1716.2,1668.1,1639.0,1586.5,559.8cm^-1；HRMS：266.1069[M+H]⁺。

Example four

Adding 35mL of purified water into a reaction bottle in advance, adding 8g of impurity I hydrochloride prepared in the second embodiment, stirring and dissolving, controlling the temperature to be 25-30 ℃, continuously dropwise adding 14.9g of 30% hydrogen peroxide, simultaneously adding the rest impurity I hydrochloride in batches, wherein the total amount of the impurity I hydrochloride is 11.0g, stirring for 2.5 hours, and then carrying out TLC detection, wherein the developing agent condition is methanol: the dichloromethane is 1:1, as shown in fig. 8, the result shows that the original point (impurity I) in the product disappears, new point is generated, the reaction is finished, and in fig. 8, "s" represents the original impurity I; "m" represents a mixture of starting impurity I and reaction product, and "r" represents the reaction product.

EXAMPLE five

Adding 35mL of purified water into a reaction bottle in advance, adding 8g of impurity I hydrochloride prepared in the second embodiment, stirring and dissolving, controlling the temperature to be 25-30 ℃, simultaneously adding the rest impurity I hydrochloride in batches, wherein the total amount of the impurity I hydrochloride is 11.0g, stirring for 2.5h, then almost colorless and clear reaction liquid is subjected to TLC detection, and the condition of a developing agent is methanol: 1:1 dichloromethane as in fig. 9, the results show that the starting material (impurity I) is not reacted, and in fig. 9, "s" represents the starting material impurity I; "m" represents a mixture of starting impurity I and reaction product, and "r" represents the reaction product.

In conclusion, the invention prepares the vitamin B₁The method for preparing the impurity I has the advantages of easily obtained raw materials, simple synthesis process and purification process and good repeatability; the obtained vitamin B₁The purity of the impurity I meets the quality requirement of the impurity. Can be used as impurity reference substance, and can be effectively applied to vitamin B₁The qualitative and quantitative analysis research of the raw material medicine and the preparation thereof on the impurity I promotes the synthesis process of the raw material medicine and the quality control research of the preparation, and ensures the treatment effect and the safety of clinical medication. In addition, tests prove that the impurity has certain reducibility, can be used as an antioxidant, and can be used as a raw material and/or an intermediate in organic synthesis reaction.

Claims

1. A compound represented by formula I or a salt thereof,

wherein R is₁And R₂Independently selected from C1 to C6 alkyl groups.

2. The compound or salt thereof as claimed in claim 1, wherein the C1-C6 alkyl is selected from C1-C4 alkyl; the alkyl of C1 to C4 is selected from one of methyl, ethyl, propyl, isopropyl, cyclopropyl, butyl, isobutyl and cyclobutyl; the salt is selected from one of hydrochloride, hydrofluoride, hydrobromide, hydroiodide, phosphate, nitrate and sulfate.

3. A method for preparing a compound shown as a formula I and a salt thereof,

in the formula I, R₁And R₂Independently selected from the group consisting of C1 to C6, characterized in that the process comprises the steps of: taking the salt of the compound shown in the formula II to react with inorganic acid,

obtaining a salt of the compound shown in the formula I; in the formula II, R₁And R₂Independently selected from C1 to C6 alkyl groups.

4. The process of claim 3, wherein the C1-C6 alkyl group is selected from the group consisting of C1-C4 alkyl groups; the alkyl of C1 to C4 is selected from one of methyl, ethyl, propyl, isopropyl, cyclopropyl, butyl, isobutyl and cyclobutyl; the salt is selected from one of hydrochloride, hydrofluoride, hydrobromide, hydroiodide, phosphate, nitrate and sulfate; the inorganic acid is selected from one of hydrochloric acid, hydrofluoric acid, hydrobromic acid, hydroiodic acid, phosphoric acid, nitric acid and sulfuric acid.

5. The preparation method of the compound shown in the formula I and the salt thereof according to claim 3, characterized in that the solvent for the reaction is water, the temperature for the reaction is 60-160 ℃, and the reaction time is 2-16 h; the method further comprises the step of concentrating the reaction solution after the reaction is finished to obtain a crude solid of the salt of the compound shown in the formula I, wherein the concentration is reduced pressure concentration, and the concentration temperature is 40-90 ℃; the method comprises the following steps of (1) before concentrating the reaction liquid, decoloring the reaction liquid, wherein a decoloring agent used for decoloring is activated carbon, the temperature of the reaction liquid is 40-50 ℃ when the decoloring agent is added, and the decoloring time is 0.1-1 hour; the molar ratio of the salt of the compound represented by the formula II to the inorganic acid is 1:1-10, preferably 1:2-6, more preferably 1: 3-4; the molar ratio of the salt of the compound shown in the formula II to the solvent water used in the reaction is 1:5-160, and the preferred molar ratio is 1: 10-50.

6. The preparation method of the compound shown in the formula I and the salt thereof according to claim 5, characterized in that the reaction temperature is 60-130 ℃, the preferable reaction temperature is 90-110 ℃, the reaction time is 2-12 h, and the preferable reaction time is 6-9 h; the method also comprises the step of recrystallizing the crude solid of the salt of the compound shown in the formula I to obtain a finished product, wherein the solvent used for recrystallization is a mixed solvent of water and alcohol, the alcohol is selected from lower alcohol, and the lower alcohol is selected from one or more of methanol, ethanol, propanol, isopropanol, butanol and isobutanol; the molar ratio of the salt of the compound shown in the formula II to the solvent water used for recrystallization is 1:8-20, and the preferred molar ratio is 1: 10-15; in the solvent used for recrystallization, the weight ratio of water to alcohol is 1:2-7, and the preferable weight ratio is 1: 4-6; the temperature of the concentration is 45-70 ℃.

8. Use of a compound of formula I or a salt thereof according to claim 1 or 2 as an antioxidant.

9. Use of a compound of formula I or a salt thereof according to claim 1 or 2 as an impurity control.

10. Use of a compound of formula I according to claim 1 or 2 or a salt thereof as a starting material and/or intermediate in an organic synthesis reaction.