New acetoxyacetyl chloride impurity as well as preparation method and detection method thereof

Abstract

The invention belongs to the technical field of biological medicine, and particularly relates to a new acetoxyacetyl chloride impurity as well as a preparation method and a detection method thereof. The invention provides an acetoxyacetyl chloride related substance 2-chloro-2-oxyethyl-2-acetoxyacetic acid ester which is not disclosed at present, and discloses a specific structure and structural characterization data of the acetoxyacetyl chloride related substance 2-chloro-2-oxyethyl-2-acetoxyacetic acid ester, and the acetoxyacetyl chloride related substance 2-chloro-2-oxyethyl-2-acetoxyacetic acid ester has remarkable positive significance for further perfecting impurity research of a roxatidine acetate hydrochloride raw material medicine. In addition, when the roxatidine acetate hydrochloride is applied to content analysis and quality control of acetoxyacetyl chloride related substances, the purity and medication safety of roxatidine acetate hydrochloride drugs can be improved.

Description

Technical Field

[0001] The invention belongs to the technical field of biomedicine, and in particular relates to a new impurity of acetoxyacetyl chloride, and a preparation method and a detection method thereof. Background Art

[0002] As one of the important starting materials of roxatidine acetate hydrochloride, acetoxyacetyl chloride has the following production process: glycolic acid is used as the starting material, reacted with acetyl chloride to generate acetoxyacetic acid, acetoxyacetic acid reacts with thionyl chloride to generate acetoxyacetyl chloride, and the product is obtained by multiple distillations. As is known to all, impurity research is an extremely important research content in the process of drug development, and impurities are inevitably introduced in the industrial production of acetoxyacetyl chloride. In order to ensure the purity of synthetic drugs, especially to ensure the purity of drugs with higher purity requirements such as roxatidine acetate hydrochloride, it is necessary to strictly control the purity and impurity content of acetoxyacetyl chloride in the quality control of acetoxyacetyl chloride. However, there is no detailed research on the related substances of acetoxyacetyl chloride and its detection methods. Summary of the invention

[0003] The inventors of the present invention analyzed the production process of acetoxyacetyl chloride and found that the industrial production of acetoxyacetyl chloride would introduce relevant impurities:

[0004] 1. Impurity acetoxyacetic acid, which is an intermediate in the preparation of acetoxyacetyl chloride and is also the main degradation product of this product;

[0005] 2. Impurity 2-chloro-2-oxoethyl-2-acetoxyacetate, which is a new impurity and has a structure as shown in Formula I. It is a process byproduct of the chlorination reaction of acetoxyacetyl chloride with glycolic acid during the preparation of this product. At the same time, this product will degrade during storage to produce acetoxyacetic acid, which will further degrade into glycolic acid. Glycolic acid and acetoxyacetyl chloride can undergo chlorination reaction, thereby generating this impurity.

[0006]

[0007] 3. Impurity acetoxyacetic anhydride, which is a by-product impurity generated by the reaction of this product with acetoxyacetic acid.

[0008] Acetoxyacetyl chloride is the starting material for preparing roxatidine acetate hydrochloride, and the above three impurities will be converted into other impurities, which will affect the quality of roxatidine acetate hydrochloride API and finished products. In particular, the impurity 2-chloro-2-oxoethyl-2-acetoxyacetate is a new compound, and no literature or patent reports have been seen. If the content of this impurity cannot be accurately controlled in the process route for synthesizing roxatidine acetate hydrochloride API, it will bring quality risks to roxatidine acetate hydrochloride. Therefore, it is necessary to strictly control the impurity content of acetoxyacetyl chloride in the quality control, especially the content of acetoxyacetic acid, 2-chloro-2-oxoethyl-2-acetoxyacetate, and acetoxyacetic anhydride, to make up for the defects in the quality control of roxatidine acetate hydrochloride.

[0009] In order to achieve the purpose of the present invention, the present invention provides a new impurity of acetoxyacetyl chloride, the chemical name of the new impurity is 2-chloro-2-oxyethyl-2-acetoxy acetate, and its structure is shown in Formula I:

[0010]

[0011] Another aspect of the present invention provides a method for preparing the compound of formula I, comprising the following steps:

[0012]

[0013] 1) benzyl glycolate reacts with acetoxyacetyl chloride to obtain compound 1;

[0014] 2) Compound 1 is debenzylated using palladium-carbon catalyst to obtain compound 2;

[0015] 3) Compound 2 is reacted with thionyl chloride to obtain 2-chloro-2-oxoethyl-2-acetoxyacetate of formula I.

[0016] In another aspect, the present invention provides the use of the compound of formula I as a reference standard for impurities in acetoxyacetyl chloride, which is used for analyzing the attribution and location of related impurities in acetoxyacetyl chloride in gas chromatography, and can also be used for quantitative analysis of the compound of formula I as an impurity in acetoxyacetyl chloride and for mass analysis of acetoxyacetyl chloride.

[0017] In another aspect, the present invention provides a method for detecting related substances of acetoxyacetyl chloride, which uses gas chromatography to perform qualitative and / or quantitative detection on acetoxyacetyl chloride and related substances, wherein the related substances at least include the above-mentioned compound of formula I or the compound of formula I prepared by the above-mentioned preparation method; preferably, the related substances at least include: 1) the above-mentioned compound of formula I or the compound of formula I prepared by the above-mentioned preparation method, and 2) one or two of acetoxyacetic acid and acetoxyacetic anhydride; further preferably, the related substances at least include: 1) the above-mentioned compound of formula I or the compound of formula I prepared by the above-mentioned preparation method, 2) acetoxyacetic acid and 3) acetoxyacetic anhydride.

[0018] In a preferred embodiment, the present invention provides a method for detecting acetoxyacetyl chloride-related substances, comprising the following steps:

[0019] 1) Mixing a diluent with acetoxyacetyl chloride or the above-mentioned acetoxyacetyl chloride-related substance to prepare a test solution or a reference solution;

[0020] 2) Detection of related substances of acetoxyacetyl chloride by gas chromatography;

[0021] Preferably, the diluent is dry acetonitrile; further preferably, the diluent is acetonitrile treated with molecular sieves.

[0022] Preferably, the test solution or reference solution is prepared before use.

[0023] Preferably, the step 1) of preparing the test solution comprises: taking an appropriate amount of acetoxyacetyl chloride, accurately weighing it, adding an appropriate amount of diluent and shaking it to dissolve it, and quantitatively diluting it with the diluent to obtain the test solution, wherein the test solution is prepared immediately before use; preferably, the diluent is acetonitrile (treated with molecular sieves).

[0024] Preferably, the step 1) of preparing the reference solution comprises: taking an appropriate amount of the above-mentioned acetoxyacetyl chloride-related substances, accurately weighing, adding an appropriate amount of diluent to dissolve and quantitatively dilute, as a reference solution, wherein the reference solution is prepared before use; preferably, the diluent is acetonitrile (treated with molecular sieves).

[0025] Preferably, the chromatographic column of the gas chromatography is a non-polar capillary column or other equivalent chromatographic column; further preferably, the non-polar capillary column is a capillary column (30m×0.53mm, 1μm) with polydimethylsiloxane as the stationary liquid; further preferably, the chromatographic column is AgilentDB-1.

[0026] Preferably, the starting temperature of the temperature rising program of the gas chromatography method in step 2) is 110°C-130°C; further preferably, the starting temperature of the temperature rising program of the gas chromatography method in step 2) is 120±5°C; further preferably, the starting temperature of the temperature rising program of the gas chromatography method in step 2) is 120°C.

[0027] Preferably, the temperature rising program of the gas chromatography method in step 2) is as follows: the starting temperature is 110°C-130°C, maintained for 4-6 minutes, increased to 210°C-230°C at a rate of 15°C-25°C per minute, and maintained for 15-25 minutes; further preferably, the temperature rising program of the gas chromatography method in step 2) is as follows: the starting temperature is 120±5°C, maintained for 5 minutes, increased to 220°C at a rate of 20°C per minute, and maintained for 20 minutes; further preferably, the temperature rising program of the gas chromatography method in step 2) is as follows: the starting temperature is 120°C, maintained for 5 minutes, increased to 220°C at a rate of 20°C per minute, and maintained for 20 minutes.

[0028] Preferably, the injection port temperature of the gas chromatography method in step (2) is 240°C-260°C; further preferably, the injection port temperature of the gas chromatography method in step (2) is 250±5°C; further preferably, the injection port temperature of the gas chromatography method in step (2) is 250°C.

[0029] Preferably, the detector and temperature of the gas chromatography in step 2) are FID, 250°C-270°C; further preferably, the detector and temperature of the gas chromatography in step 2) are FID, 260±5°C; further preferably, the detector and temperature of the gas chromatography in step 2) are FID, 260°C.

[0030] Preferably, the carrier gas for gas chromatography in step 2) is nitrogen, and the flow rate is 1.3ml-1.7ml per minute; further preferably, the carrier gas for gas chromatography in step 2) is nitrogen, and the flow rate is 1.5±0.1ml per minute; further preferably, the carrier gas for gas chromatography in step 2) is nitrogen, and the flow rate is 1.5ml per minute.

[0031] Preferably, the injection mode of the gas chromatography method in step 2) is split injection, and the split ratio is (30:1)-(50:1); further preferably, the injection mode of the gas chromatography method in step 2) is split injection, and the split ratio is 40:1.

[0032] Preferably, the injection volume of the gas chromatography in step 2) is 1 μl.

[0033] In a preferred embodiment, the present invention provides a method for detecting acetoxyacetyl chloride-related substances, comprising the following steps:

[0034] 1) using molecular sieve treated acetonitrile and acetoxyacetyl chloride or acetoxyacetyl chloride related substances to prepare a test solution or a reference solution, wherein the test solution or the reference solution is prepared before use;

[0035] 2) Detection of related substances of acetoxyacetyl chloride by gas chromatography;

[0036] Among them, the related substances of acetoxyacetyl chloride include at least 2-chloro-2-oxoethyl-2-acetoxyacetate, acetoxyacetic acid and acetoxyacetic anhydride, and the chromatographic conditions of gas chromatography are as follows:

[0037] Chromatographic column: a capillary column with polydimethylsiloxane as the stationary liquid (Agilent DB-1, 30m×0.53mm, 1μm or a chromatographic column with equivalent polarity);

[0038] Heating program: starting temperature is 120°C, maintained for 5 minutes, increased to 220°C at a rate of 20°C per minute, maintained for 20 minutes;

[0039] Inlet temperature: 250°C; detector (FID) temperature: 260°C; carrier gas: nitrogen; flow rate: 1.5 ml per minute; split ratio: 40:1.

[0040] Terminology

[0041] The acetoxyacetyl chloride and the product of the present invention both refer to acetoxyacetyl chloride.

[0042] The gas chromatography method and GC method in the present invention both refer to gas chromatography method.

[0043] The molecular sieve-treated acetonitrile of the present invention refers to acetonitrile obtained by removing water from acetonitrile using molecular sieves according to conventional techniques in the art.

[0044] The present invention establishes a gas chromatography method for the determination of acetoxyacetyl chloride-related substances and performs methodological verification on it. The results show that the established method meets the requirements of the "Guidelines for Validation of Analytical Methods for Drug Quality Standards" of the 2020 edition of the Chinese Pharmacopoeia. Compared with the prior art, the present invention has the following beneficial effects:

[0045] 1. The present application provides a currently undisclosed acetoxyacetyl chloride related substance 2-chloro-2-oxoethyl-2-acetoxyacetate, and discloses its specific structure and structural characterization data, which has a significant positive significance for further improving the impurity research of roxatidine acetate hydrochloride raw material; applying it to the content analysis and quality control of acetoxyacetyl chloride related substances is helpful to improve the purity and medication safety of roxatidine acetate hydrochloride drugs.

[0046] 2. The present invention provides an effective way to detect the purity and impurity content of acetoxyacetyl chloride, a raw material for drug synthesis, which makes up for the shortcomings of the prior art, provides an acetoxyacetyl chloride product with clear and controllable purity, and facilitates the selection and use of raw materials.

[0047] 3. The chromatographic column selected in the present invention has a high matching degree with the acetoxyacetyl chloride and related substances to be measured, the peak shape of the acetoxyacetyl chloride and related substances to be measured is good, the separation degree with the adjacent peaks is good, and the method running time is short (the peak retention time of acetoxyacetyl chloride is about 5.9min), and there are no other impurities in the test solution that interfere with the determination of the content, and the purity of acetoxyacetyl chloride and the content of related substances can be achieved. Rapid quantitative analysis.

[0048] 4. The method provided by the present invention has good specificity, good durability and good reproducibility. Changing the chromatographic conditions such as flow rate, column temperature and wavelength within a small range will not affect the detection of acetoxyacetyl chloride-related substances.

[0049] 5. The present invention uses acetonitrile treated with molecular sieves as a diluent, and the test solution is freshly prepared before use, so as to avoid degradation of acetoxyacetyl chloride and impurity acetoxyacetic anhydride by contact with the diluent and water in the air to the greatest extent. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 This is the blank solution spectrum in Example 2;

[0051] Figure 2 The acetoxyacetic acid localization solution spectrum in Example 2;

[0052] Figure 3 It is the localization solution spectrum of 2-chloro-2-oxoethyl-2-acetoxyacetate in Example 2;

[0053] Figure 4 This is the acetoxyacetic anhydride localization solution spectrum in Example 2;

[0054] Figure 5 is the system suitability solution spectrum in Example 2;

[0055] Figure 6 The sample solution in Example 3 is shown in FIG.

[0056] Figure 7 Spectrum of the test sample solution in Comparative Example 1 (diluent acetonitrile);

[0057] Figure 8 Spectrum of the test sample solution in Comparative Example 2 (diluent tetrahydrofuran). DETAILED DESCRIPTION

[0058] The following representative examples are for better illustrating the present invention, but are not intended to limit the scope of protection of the present invention. Unless otherwise specified, the raw materials and reagents used in the following examples are all commercially available products, and the experimental equipment involved are all commonly used laboratory equipment.

[0059] Example 1 Preparation of 2-chloro-2-oxoethyl-2-acetoxyacetate

[0060] (1) Synthesis route

[0061]

[0062] (2) Preparation method

[0063] Dissolve 10 g of benzyl glycolate in 50 ml of dichloromethane, slowly add 8.2 g of acetoxyacetyl chloride, concentrate the reaction solution after the reaction, and purify it by column chromatography to obtain compound 1. Dissolve 3 g of compound 1 in 15 ml of methanol, add 0.31 g of palladium carbon, replace hydrogen three times, filter and concentrate after the reaction to obtain compound 2. Take 1 g of compound 2 and 10 ml of dichlorothionyl, add them to a reaction bottle, react at 45 ° C, and concentrate to dryness to obtain the target impurity.

[0064] 2-Chloro-2-oxoethyl-2-acetoxyacetate is a process impurity of acetoxyacetyl chloride, which can be separated from acetoxyacetyl chloride. Preparation process: Take a certain amount of acetoxyacetyl chloride, distill under reduced pressure, set the temperature at 70℃-90℃, distill under reduced pressure until no obvious liquid flows out, and then distill for 30 minutes. The residue is 2-chloro-2-oxoethyl-2-acetoxyacetate, which is nitrogen-filled for protection after transfer. 1 HNMR (DMSO- d6 ,400MHz): δ4.74(s,2H),4.65(s,2H),2.10(s,3H).

[0065] Example 2

[0066] Instruments: Gas chromatograph model 7890B, purchased from Agilent; electronic balance model XPE205, purchased from Mettler.

[0067] Blank solvent: acetonitrile (treated with molecular sieves).

[0068] Acetoxyacetic acid reference stock solution: Take an appropriate amount of acetoxyacetic acid impurity reference substance, weigh accurately, add diluent to dissolve and quantitatively dilute to make a solution containing about 20 mg per 1 ml.

[0069] 2-Chloro-2-oxoethyl-2-acetoxyacetate reference substance stock solution: Take an appropriate amount of 2-chloro-2-oxoethyl-2-acetoxyacetate impurity reference substance, accurately weigh it, add diluent to dissolve it and quantitatively dilute it to make a solution containing about 10 mg per 1 ml.

[0070] Acetoxyacetic anhydride reference stock solution: Take an appropriate amount of acetoxyacetic anhydride impurity reference substance, accurately weigh it, add diluent to dissolve it and quantitatively dilute it to make a solution containing about 10 mg per 1 ml.

[0071] System suitability solution: Take 1000 mg of this product, weigh accurately, place in a 10 ml volumetric flask, add 1 ml of each impurity stock solution, dilute to the scale with diluent, shake well, and obtain.

[0072] The above solution was analyzed by gas chromatography (prepared before use) and the chromatogram was recorded. The chromatographic conditions of the gas chromatography were as follows:

[0073] Chromatographic column: A capillary column with polydimethylsiloxane as the stationary liquid (Agilent DB-1, 30 m × 0.53 mm, 1 μm);

[0074] Heating program: starting temperature is 120°C, maintained for 5 minutes, increased to 220°C at a rate of 20°C per minute, maintained for 20 minutes;

[0075] Inlet temperature: 250°C; detector (FID) temperature: 260°C; carrier gas: nitrogen; flow rate: 1.5 ml per minute; split ratio: 40:1; injection volume: 1 μl.

[0076] The blank solution spectrum obtained is as follows Figure 1 As shown, the acetoxyacetic acid localization solution spectrum is as follows Figure 2 As shown, the 2-chloro-2-oxoethyl-2-acetoxyacetate localization solution spectrum is as follows Figure 3 As shown, the acetoxyacetic anhydride localization solution spectrum is as follows Figure 4 As shown, the system suitability solution spectrum is as follows Figure 5 The separation results are shown in the following table:

[0077]

[0078] The injection precision results are shown in the following table:

[0079]

[0080] The results showed that the separation degree between the main peak and specific impurity peak and the adjacent impurity peaks in the system suitability solution was greater than 1.5; the system suitability solution was injected 6 times continuously, and the RSD of the main peak area was 0.7%, less than 10.0%, and the RSD of the retention time was 0.1%, less than 1.0%, which met the requirements.

[0081] Example 3-11

[0082] Blank solvent: acetonitrile (treated with molecular sieves)

[0083] Test solution: Take an appropriate amount of the product, weigh it accurately, add an appropriate amount of diluent and shake to dissolve it, quantitatively dilute it with the diluent to make a solution containing about 100 mg per 1 ml, shake well, and you have it.

[0084] Analyze the above solution (prepared immediately before use) by gas chromatography and record the chromatogram. The instrument and chromatographic conditions of Example 3 are the same as those of Example 2; the instruments of Examples 4-11 are the same as those of Example 2, except that one of the parameters in the chromatographic conditions is changed, among which the injection port temperature of Examples 4-5 is changed, the flow rate of Examples 6-7 is changed, the detector temperature of Examples 8-9 is changed, and the starting temperature of Examples 10-11 is changed. The sample solution spectrum of Example 3 is shown in Figure 6 The changes in the chromatographic parameters and results of other gas chromatography conditions are shown in the following table:

[0085]

[0086] The results showed that under the conditions of various experimental parameter changes, the separation between the main peak and the preceding and following impurities in the test solution met the requirements; the absolute deviation of the changes in each impurity and total impurities in the test solution was no more than 20% of the limit, indicating that the method has a certain durability.

[0087] Example 12

[0088] 1. Exclusivity

[0089] Blank solvent: acetonitrile (treated with molecular sieves)

[0090] Stock solutions of each impurity reference substance: prepare the stock solutions of each impurity reference substance according to Example 2.

[0091] Test solution: Take an appropriate amount of the product, weigh it accurately, add an appropriate amount of diluent and shake to dissolve it, and quantitatively dilute it with the diluent to make a solution containing about 100 mg per 1 ml as the test solution.

[0092] The above solution was analyzed by gas chromatography (prepared before use) and the chromatogram was recorded. The chromatographic conditions of the gas chromatography were as follows:

[0093] Chromatographic column: A capillary column with polydimethylsiloxane as the stationary liquid (Agilent DB-1, 30 m × 0.53 mm, 1 μm);

[0094] Heating program: starting temperature is 120°C, maintained for 5 minutes, increased to 220°C at a rate of 20°C per minute, maintained for 20 minutes;

[0095] Inlet temperature: 250°C; detector (FID) temperature: 260°C; carrier gas: nitrogen; flow rate: 1.5 ml per minute; split ratio: 40:1; injection volume: 1 μl.

[0096] The results are shown in the table below:

[0097]

[0098] The results showed that the blank solvent did not interfere with the detection of the main components and known impurities; the separation degree between the main components and specific impurities of the test solution and the adjacent impurities was greater than 1.5, which met the requirements, indicating that the method had good specificity.

[0099] 2. Linear range

[0100] Blank solvent: acetonitrile (treated with molecular sieves)

[0101] Acetoxyacetic acid linear stock solution: Take an appropriate amount of acetoxyacetic acid reference substance, weigh accurately, add diluent to dissolve and quantitatively dilute to make a solution containing about 20 mg of each impurity per 1 ml as the linear stock solution. Prepare the linear solution according to the following table:

[0102] Linear solution Linear Level Volume of stock solution pipetted (ml) Volume of measuring flask (ml) L1 LOQ / / L2 50％ 1 20 L3 100％ 2 20 L4 150％ 3 20 L5 200％ 4 20

[0103] Mixed impurity linear stock solution: Take appropriate amount of 2-chloro-2-oxoethyl-2-acetoxyacetate and acetoxyacetic anhydride reference substances, weigh accurately, add diluent to dissolve and quantitatively dilute to make a solution containing about 20 mg of each impurity per 1 ml as linear stock solution, and prepare linear solution according to the following table:

[0104]

[0105] Linear stock solution of acetoxyacetyl chloride: Accurately weigh an appropriate amount of acetoxyacetyl chloride reference substance, add diluent and ultrasonically dissolve until diluted to make a solution containing about 125 mg per 1 ml, as the linear stock solution, and prepare the linear solution according to the following table:

[0106] Linear solution Linear Level Volume of stock solution pipetted (ml) Volume of measuring flask (ml) L1 LOQ / / L2 25％ 2 10 L3 50％ 4 10 L4 100％ 8 10

[0107] The above solution was analyzed by gas chromatography (prepared before use) and the chromatogram was recorded. The chromatographic conditions of the gas chromatography were as follows:

[0108] Chromatographic column: A capillary column with polydimethylsiloxane as the stationary liquid (Agilent DB-1, 30 m × 0.53 mm, 1 μm);

[0109] Heating program: starting temperature is 120°C, maintained for 5 minutes, increased to 220°C at a rate of 20°C per minute, maintained for 20 minutes;

[0110] Inlet temperature: 250°C; detector (FID) temperature: 260°C; carrier gas: nitrogen; flow rate: 1.5 ml per minute; split ratio: 40:1; injection volume: 1 μl.

[0111] The results show:

[0112] When the concentration of acetoxyacetyl chloride is in the range of 23.749-118746.516 ug / ml, the linear regression equation is y=0.0558x-189.8918; r is 0.996, which is greater than 0.990; the Y-axis intercept is 189.8918, which is less than 25% of the 100% response value, and the linear relationship is good.

[0113] When the concentration of acetoxyacetic acid was in the range of 95.182-3807.296 ug / ml, the linear regression equation was y=0.0533x-7.4956; r was 0.999, which was greater than 0.990; the Y-axis intercept was 7.4956, which was less than 25% of the 100% response value, and the linear relationship was good.

[0114] The linear regression equation of 2-chloro-2-oxoethyl-2-acetoxyacetate in the concentration range of 87.956-1759.128ug / ml is y=0.0388x-2.0012; r is 0.997, which is greater than 0.990; the Y-axis intercept is 2.0012, which is less than 25% of the 100% response value, and the linear relationship is good.

[0115] When the concentration of acetoxyacetic anhydride is within the range of 47.334-1893.360ug / ml, the linear regression equation is y=0.0626x-2.9139; r is 0.999, which is greater than 0.990; the Y-axis intercept is 2.9139, which is less than 25% of the 100% response value, and the linear relationship is good.

[0116] 3. Limit of detection and limit of quantification

[0117] Detection limit solution: Take the stock solutions of each reference substance under "2. Linear range" and dilute them step by step. Inject the sample and the detection limit solution is when the signal-to-noise ratio is about 3:1.

[0118] Quantitative limit solution: Take the reference substance stock solutions under "2. Linear range" and dilute them step by step. Inject the sample. When the signal-to-noise ratio is about 10:1, it is the quantitative limit solution.

[0119] The above solution was analyzed by gas chromatography (prepared before use) and the chromatogram was recorded. The chromatographic conditions of the gas chromatography were as follows:

[0120] Chromatographic column: A capillary column with polydimethylsiloxane as the stationary liquid (Agilent DB-1, 30 m × 0.53 mm, 1 μm);

[0121] Heating program: starting temperature is 120°C, maintained for 5 minutes, increased to 220°C at a rate of 20°C per minute, maintained for 20 minutes;

[0122] Inlet temperature: 250°C; detector (FID) temperature: 260°C; carrier gas: nitrogen; flow rate: 1.5 ml per minute; split ratio: 40:1; injection volume: 1 μl.

[0123] The detection limit and quantification limit test results are shown in the table below:

[0124]

[0125] The results of the quantitative limit precision test are shown in the following table:

[0126]

[0127]

[0128] The results show:

[0129] The detection limit concentration of acetoxyacetyl chloride in this detection method is 11.875μg / ml, and the quantification limit concentration is 23.749μg / ml. At this concentration level, the peak area RSD of 6 injections is 5.4%, less than 10.0%, and the retention time RSD is less than 1.0%;

[0130] The detection limit of acetoxyacetic acid in this detection method is 47.591 μg / ml, and the quantification limit is 95.182 μg / ml. At this concentration level, the peak area RSD of 6 injections is 9.3%, less than 10.0%, and the retention time RSD is less than 1.0%;

[0131] The detection limit of 2-chloro-2-oxoethyl-2-acetoxyacetate in this detection method is 26.387 μg / ml, and the quantification limit is 87.956 μg / ml. At this concentration level, the peak area RSD of 6 injections is 6.0%, less than 10.0%, and the retention time RSD is less than 1.0%;

[0132] The detection limit of acetoxyacetic anhydride in this detection method is 14.200 μg / ml, and the quantification limit is 47.334 μg / ml. At this concentration level, the peak area RSD of 6 injections is 4.1%, less than 10.0%, and the retention time RSD is less than 1.0%;

[0133] All of the above meet the requirements, proving that the measurement results have a certain degree of precision at the quantitative limit concentration level of each impurity.

[0134] 4. Repeatability test

[0135] Blank solvent: acetonitrile (treated with molecular sieves)

[0136] Repeatability test solution: Take an appropriate amount of this product, weigh it accurately, add an appropriate amount of diluent and shake to dissolve it, quantitatively dilute it with the diluent to make a solution containing about 100 mg per 1 ml, and make 6 parallel copies.

[0137] The above solution was analyzed by gas chromatography (prepared before use) and the chromatogram was recorded. The chromatographic conditions of the gas chromatography were as follows:

[0138] Chromatographic column: A capillary column with polydimethylsiloxane as the stationary liquid (Agilent DB-1, 30 m × 0.53 mm, 1 μm);

[0139] Heating program: starting temperature is 120°C, maintained for 5 minutes, increased to 220°C at a rate of 20°C per minute, maintained for 20 minutes;

[0140] Inlet temperature: 250°C; detector (FID) temperature: 260°C; carrier gas: nitrogen; flow rate: 1.5 ml per minute; split ratio: 40:1; injection volume: 1 μl.

[0141] The repeatability test results are shown in the following table:

[0142]

[0143] The results of 6 measurements showed that the average content of acetoxyacetic acid was 0.51%, RSD was 5.8%, less than 10.0%; the average content of 2-chloro-2-oxoethyl-2-acetoxyacetate was 0.02%, the range was 0.01%, less than 0.02%; the average content of acetoxyacetic anhydride was 0.65%, RSD was 4.5%, less than 10.0%; the average content of the unknown largest single impurity was 0.18%, RSD was 3.0%, less than 10.0%; the average content of total impurities was 1.40%, RSD was 2.7%, less than 10.0%. It met the requirements and proved that the method had good repeatability.

[0144] Embodiment 13

[0145] Blank solvent: acetonitrile (treated with molecular sieves) Test solution: Take an appropriate amount of the product, weigh it accurately, add an appropriate amount of diluent and shake to dissolve it, quantitatively dilute it with the diluent to make a solution containing about 100 mg per 1 ml, shake well, and you have it.

[0146] The above solution was analyzed by gas chromatography and the chromatogram was recorded. The chromatographic conditions of the gas chromatography were as follows:

[0147] Chromatographic column: A capillary column with polydimethylsiloxane as the stationary liquid (Agilent DB-1, 30 m × 0.53 mm, 1 μm);

[0148] Heating program: starting temperature is 120°C, maintained for 5 minutes, increased to 220°C at a rate of 20°C per minute, maintained for 20 minutes;

[0149] Inlet temperature: 250°C; detector (FID) temperature: 260°C; carrier gas: nitrogen; flow rate: 1.5 ml per minute; split ratio: 40:1; injection volume: 1 μl.

[0150] The solution stability test results are shown in the following table:

[0151]

[0152]

[0153] The results showed that under room temperature conditions, the ratio of the acetoxyacetic acid peak area of ​​the test solution at 0.5h was 135.5% compared with that at 0h, which was beyond the range of 80.0% to 120.0%. The absolute value of the change in total impurity content was greater than 0.05%, indicating that the test solution had poor stability and needed to be prepared before use.

[0154] Comparative Example 1

[0155] Preparation of test solution: Take an appropriate amount of the product, weigh it accurately, add an appropriate amount of acetonitrile and shake to dissolve it, quantitatively dilute it with acetonitrile to make a solution containing about 100 mg per 1 ml, shake well, and you have it.

[0156] Analyze the test solution (prepared before use) by gas chromatography and record the chromatogram. The chromatographic conditions of the gas chromatography are as follows:

[0157] Chromatographic column: a capillary column with polydimethylsiloxane as the stationary liquid (Agilent DB-1, 30m×0.53mm, 1μm or a chromatographic column with equivalent polarity);

[0158] Heating program: starting temperature is 120°C, maintained for 5 minutes, increased to 220°C at a rate of 20°C per minute, maintained for 10 minutes;

[0159] Inlet temperature: 250°C; detector (FID) temperature: 260°C; carrier gas: nitrogen; flow rate: 1.5 ml per minute; split ratio: 40:1; injection volume: 1 μl.

[0160] The obtained chromatogram is as follows Figure 7 The results are shown in the following table:

[0161]

[0162]

[0163] The results show that the peak area of ​​acetoxyacetic acid in Comparative Example 1 is 1.06%, and the peak area of ​​acetoxyacetic anhydride is 0.81%; while in Example 3 (using acetonitrile treated with molecular sieves as the diluent), the peak area of ​​acetoxyacetyl chloride in the test solution is 98.74, the peak area of ​​acetoxyacetic acid is 0.13, the peak area of ​​acetoxyacetic anhydride is 0.28, and the peak area of ​​2-chloro-2-oxoethyl-2-acetoxyacetate is 0.51. Therefore, compared with Example 3, the detection results of acetoxyacetic acid and acetoxyacetic anhydride in Comparative Example 1 are significantly larger, indicating that the trace amount of water in the undried acetonitrile affects the detection results.

[0164] Comparative Example 2

[0165] Preparation of test solution: Take an appropriate amount of the product, weigh it accurately, add an appropriate amount of tetrahydrofuran and shake to dissolve it, quantitatively dilute it with tetrahydrofuran to make a solution containing about 100 mg per 1 ml, shake well, and you have it.

[0166] Analyze the test solution (prepared before use) by gas chromatography and record the chromatogram. The chromatographic conditions of the gas chromatography are as follows:

[0167] Chromatographic column: a capillary column with polydimethylsiloxane as the stationary liquid (Agilent DB-1, 30m×0.53mm, 1μm or a chromatographic column with equivalent polarity);

[0168] Heating program: starting temperature is 120°C, maintained for 5 minutes, increased to 220°C at a rate of 20°C per minute, maintained for 10 minutes;

[0169] Inlet temperature: 250°C; detector (FID) temperature: 260°C; carrier gas: nitrogen; flow rate: 1.5 ml per minute; split ratio: 40:1; injection volume: 1 μl.

[0170] The obtained chromatogram is as follows Figure 8 As shown in the following table,

[0171]

[0172]

[0173] The results showed that undried tetrahydrofuran reacted with the test sample as a diluent, producing new impurities and an uneven baseline.

Claims

1. A new impurity of acetoxyacetyl chloride, the chemical name of the new impurity is 2-chloro-2-oxoethyl-2-acetoxyacetate, and its structure is shown in Formula I:

2. A method for preparing the compound of formula I according to claim 1, comprising the following steps: 1) benzyl glycolate reacts with acetoxyacetyl chloride to obtain compound 1; 2) Compound 1 is debenzylated using palladium-carbon catalyst to obtain compound 2; 3) Compound 2 is reacted with thionyl chloride to obtain 2-chloro-2-oxoethyl-2-acetoxyacetate of formula I.

3. A method for detecting related substances of acetoxyacetyl chloride, characterized in that: Gas chromatography is used to perform qualitative and / or quantitative detection of acetoxyacetyl chloride and related substances, wherein the related substances include at least the compound of formula I according to claim 1 or the compound of formula I prepared by the preparation method according to claim 2; preferably, the related substances include at least: 1) the compound of formula I according to claim 1 or the compound of formula I prepared by the preparation method according to claim 2, and 2) one or two of acetoxyacetic acid and acetoxyacetic anhydride; further preferably, the related substances include at least: 1) the compound of formula I according to claim 1 or the compound of formula I prepared by the preparation method according to claim 2, 2) acetoxyacetic acid and 3) acetoxyacetic anhydride.

4. The detection method according to claim 3, characterized in that: The following steps are involved: 1) using a diluent and acetoxyacetyl chloride or the acetoxyacetyl chloride-related substance of claim 3 to mix to prepare a test solution or a reference solution; 2) Detection of related substances of acetoxyacetyl chloride by gas chromatography; Preferably, the diluent is dry acetonitrile; further preferably, the diluent is acetonitrile treated with molecular sieves.

5. The detection method according to claim 4, characterized in that: The test solution or reference solution is prepared before use.

6. The detection method according to claim 4, characterized in that: The chromatographic column of the gas chromatography is a non-polar capillary column or other equivalent chromatographic column; further preferably, the non-polar capillary column is a capillary column (30m×0.53mm, 1μm) with polydimethylsiloxane as the stationary liquid; further preferably, the chromatographic column is Agilent DB-1.

7. The detection method according to claim 4, characterized in that: The starting temperature of the heating program of the gas chromatography method in step 2) is 110°C-130°C; the detector and temperature of the gas chromatography method in step 2) are FID, 250°C-270°C; the carrier gas of the gas chromatography method in step 2) is nitrogen; the flow rate is 1.3ml-1.7ml per minute; the injection mode of the gas chromatography method in step 2) is split injection, and the split ratio is (30:1)-(50:1).

8. The detection method according to claim 4, characterized in that: The temperature rising program of the gas chromatography method in step 2) is as follows: the starting temperature is 110°C-130°C, maintained for 4-6 minutes, increased to 210°C-230°C at a rate of 15°C-25°C per minute, and maintained for 15-25 minutes; further preferably, the temperature rising program of the gas chromatography method in step 2) is as follows: the starting temperature is 120±5°C, maintained for 5 minutes, increased to 220°C at a rate of 20°C per minute, and maintained for 20 minutes; further preferably, the temperature rising program of the gas chromatography method in step 2) is as follows: the starting temperature is 120°C, maintained for 5 minutes, increased to 220°C at a rate of 20°C per minute, and maintained for 20 minutes.

9. The detection method according to claim 4, characterized in that: The following steps are involved: 1) using molecular sieve treated acetonitrile and acetoxyacetyl chloride or a related substance of acetoxyacetyl chloride to prepare a test solution or a reference solution, wherein the test solution or the reference solution is prepared before use; 2) Detection of related substances of acetoxyacetyl chloride by gas chromatography; Among them, the related substances of acetoxyacetyl chloride include at least 2-chloro-2-oxoethyl-2-acetoxyacetate, acetoxyacetic acid and acetoxyacetic anhydride; The chromatographic conditions of gas chromatography are as follows: Chromatographic column: a capillary column with polydimethylsiloxane as the stationary liquid (Agilent DB-1, 30m×0.53mm, 1μm or a chromatographic column with equivalent polarity); Heating program: starting temperature is 120°C, maintained for 5 minutes, increased to 220°C at a rate of 20°C per minute, maintained for 20 minutes; Inlet temperature: 250°C; detector (FID) temperature: 260°C; carrier gas: nitrogen; flow rate: 1.5 ml per minute; split ratio: 40:

1.

10. Use of the compound of formula I according to claim 1 or the compound of formula I prepared by the preparation method according to claim 2 as a reference substance for acetoxyacetyl chloride impurities.

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