阅读说明：本技术 一种甲氧氯普胺双氯新杂质的制备方法 (Preparation method of new metoclopramide dichlorine impurity ) 是由 殷晓伟 王姝 于 2021-09-30 设计创作，主要内容包括：本发明公开了一种通过氯代反应、水解反应、酰胺化反应制备甲氧氯普胺双氯新杂质的方法。本发明的制备方法具有操作简便、成本低廉且收率较高等优点,制备得到的甲氧氯普胺双氯新杂质纯度大于99%,可以作为对照品用于甲氧氯普胺的质量研究。(The invention discloses a method for preparing a new metoclopramide dichlorine impurity through chlorination reaction, hydrolysis reaction and amidation reaction. The preparation method has the advantages of simple and convenient operation, low cost, high yield and the like, and the purity of the prepared metoclopramide dichlorine impurity is more than 99 percent, and the metoclopramide dichlorine impurity can be used as a reference substance for the quality research of metoclopramide.)

1. A preparation method of a new metoclopramide dichlorine impurity is characterized by comprising the following reaction steps:

(1) reacting the compound shown in the formula II with a chlorinated reagent to generate a compound shown in the formula III;

(2) reacting the compound shown in the formula III with an alkaline reagent to generate a compound shown in the formula IV;

(3) and reacting the compound shown in the formula IV with N, N-diethyl ethylenediamine in the presence of CDI to obtain the compound shown in the formula I.

2. The method for preparing metoclopramide bischloro new impurity as claimed in claim 1, wherein said chlorinating agent in step (1) is selected from the group consisting of Cl₂、Cl₂O、S₂Cl₂、SO₂Cl₂One or more of t-BuOCl and NCS; the molar ratio of the chlorinated reagent to the compound of the formula II is 1: 1-3: 1.

3. The method for preparing metoclopramide bischloro new impurity according to claim 2, wherein said chlorinating agent in step (1) is selected from the group consisting of NCS; the molar ratio of the chlorinating reagent to the compound of formula II is 2: 1.

4. The method for preparing metoclopramide bischloro new impurity as claimed in claim 1, wherein optionally, said step (1) further comprises the step of recrystallization with tetrahydrofuran/petroleum ether; the volume ratio of the tetrahydrofuran to the petroleum ether is 5: 10-5: 20.

5. The method for preparing metoclopramide dichlorine new impurity as claimed in claim 1, wherein the alkaline reagent in step (2) is one or more of LiOH, NaOH or KOH; the molar ratio of the alkaline reagent to the compound of the formula III is 2: 1-4: 1.

6. The method for preparing metoclopramide bischloro new impurity as claimed in claim 1, wherein said step (2) further comprises the steps of pH adjustment, pulping with water, filtering, and recrystallization with ethanol/water.

7. The method for preparing a new impurity metoclopramide dichloride as claimed in claim 6, wherein the pH is adjusted to 4-6.

8. The method for preparing metoclopramide dichlorine new impurity as claimed in claim 1, wherein the reaction solvent in step (3) is one or more of acetonitrile, dichloromethane, chloroform, tetrahydrofuran, N-dimethylformamide or N, N-dimethylacetamide.

9. The method for preparing new metoclopramide dichlorine impurities as claimed in claim 1, wherein the molar ratio of CDI, N-diethylethylenediamine and the compound of formula IV in step (3) is 1-1.5: 1.

10. The method for preparing metoclopramide dichlorine new impurity as claimed in claim 1, wherein the reaction temperature of the step (1) is 70-100 ℃; the reaction temperature in the step (2) is 0 ℃ to the reflux temperature of the system; the reaction temperature of the step (3) is 0 ℃ to the reflux temperature of the system.

Technical Field

The invention relates to the technical field of biological medicines, and in particular relates to a preparation method of a new metoclopramide dichlorine impurity.

Background

Metoclopramide, also known as chlorpromamide, also known as metoclopramide, has a molecular formula of C₁₄H₂₂ClN₃O₂White to pale yellow crystalline powder with molecular weight of 299.7964 and CAS registry number of 364-62-5, and strong central antiemetic effect.

Metoclopramide can be used for treating emesis caused by brain tumor operation, radiotherapy and chemotherapy of tumor, cerebral trauma sequelae, acute craniocerebral injury, and medicine. Has good curative effect on flatulence dyspepsia, inappetence, belching, nausea and vomiting, and can also be used for vomiting and carsickness (ship) caused by sea-air operation. In addition, metoclopramide can relieve nausea and vomiting reaction during barium meal examination and promote barium agent to pass through; or the medicine is taken before the duodenum is intubated, which is beneficial to smooth intubatton; or for the adjuvant treatment of biliary tract diseases and chronic pancreatitis.

The metoclopramide raw material medicine synthetic route adopted by the applicant is as follows:

unknown impurities are found in the synthesis process, and a brand new impurity is obtained by crystallizing the IM2 material and separating and enriching the mother liquor, as shown in formula I.

In the process of developing new medicines, the impurity content of the medicines directly influences the curative effect and the toxic and side effects of the medicines, so that the control of the impurity limit and the improvement of the purity are very important for ensuring the safety, the effectiveness and the quality controllability of the medicines. Therefore, the invention further develops a preparation method of the new metoclopramide dichlorine impurity so as to realize stricter quality control of the medicine.

Disclosure of Invention

The invention aims to solve the technical problem of providing a preparation method of a new metoclopramide dichlorine impurity, wherein the purity of the prepared new metoclopramide dichlorine impurity is more than 99 percent, and the new metoclopramide dichlorine impurity can be used as a reference substance for the quality research of metoclopramide.

The invention provides a preparation method of a new metoclopramide dichlorine impurity shown as a formula I, which is characterized by comprising the following reaction steps:

(1) reacting the compound shown in the formula II with a chlorinated reagent to generate a compound shown in the formula III;

(2) reacting the compound shown in the formula III with an alkaline reagent to generate a compound shown in the formula IV;

(3) and reacting the compound shown in the formula IV with N, N-diethyl ethylenediamine in the presence of CDI to obtain the compound shown in the formula I.

Further, the chlorinating reagent in the step (1) is selected from Cl₂、Cl₂O、S₂Cl₂、SO₂Cl₂One or more of t-BuOCl and NCS, preferably NCS; the molar ratio of the chlorinated reagent to the compound of the formula II is 1: 1-3: 1, preferably 2: 1;

further, optionally, the step (1) further comprises a step of recrystallization with tetrahydrofuran/petroleum ether; the volume ratio of the tetrahydrofuran to the petroleum ether is 5: 10-5: 20, preferably 5: 16;

further, the alkaline reagent in the step (2) is one or more of LiOH, NaOH or KOH, and NaOH is preferred; the molar ratio of the alkaline reagent to the compound of the formula III is 2: 1-4: 1, preferably 2.5: 1-3.5: 1, and more preferably 3.2: 1;

further, optionally, the step (2) further comprises the steps of adjusting pH, adding water for pulping, filtering, adding ethanol/water for recrystallization; the pH adjusting step is to adjust the pH to 4-6 by using hydrochloric acid, preferably to adjust the pH to 5 by using 1M hydrochloric acid;

further, the reaction solvent in the step (3) is one or more of acetonitrile, dichloromethane, chloroform, tetrahydrofuran, N-dimethylformamide or N, N-dimethylacetamide, and dichloromethane is preferred;

further, the molar ratio of the CDI, the N, N-diethyl ethylenediamine and the compound shown in the formula IV in the step (3) is 1-1.5: 1, preferably 1:1: 0.9;

further, the reaction temperature of the step (1) is 70-100 ℃, preferably 80-90 ℃, and more preferably 85 ℃;

the reaction temperature in the step (2) is 0 ℃ to the system reflux temperature, and the system reflux temperature is preferably selected;

the reaction temperature in the step (3) is 0 ℃ to the system reflux temperature, wherein the reaction temperature after the CDI is added is preferably 30-40 ℃, and the reaction temperature after the N, N-diethylethylenediamine is added is preferably the system reflux temperature;

the Chinese naming of the compound of the invention conflicts with the structural formula, and the structural formula is taken as the standard; except for obvious errors in the formula.

The invention discloses a preparation method of a new metoclopramide dichlorine impurity, wherein the purity of the obtained new metoclopramide dichlorine impurity is more than 99%, the new metoclopramide dichlorine impurity can be used as a reference substance for the quality research of metoclopramide, and the preparation method has the advantages of simple operation, low cost, high yield and the like.

Drawings

FIG. 1: mass spectrogram of the new impurity of metoclopramide dichloride, namely the compound of the formula I;

FIG. 2: a hydrogen spectrum of a compound of formula I as a novel impurity of metoclopramide dichloride.

Detailed Description

The invention is illustrated but not limited by the following examples. The technical solutions protected by the present invention are all the simple replacements or modifications made by the skilled person in the art.

Example 1:

(1)4- (acetylamino) -3, 5-dichloro-2-methoxybenzoic acid methyl ester (formula III)

A three-necked flask was charged with a compound of formula II (36g,0.14mol), DMF100mL, NCS (37.4g,0.28mol) heated to an internal temperature of 85 ℃ and allowed to react for 5 hours, after which the reaction mixture was poured into ice water, extracted with EA 100mL × 3 times, the combined organic phases were washed with water 100mL × 2 times, separated, dried over anhydrous sodium sulfate, concentrated to give a yellow solid 30.2g, recrystallized from THF/PE 5:16 to give 23.6g of an off-white solid, yield 57.9%, mp: 137 ℃ and 139 ℃, ESI-MS (M/z):291.98[ M + H]⁺。

(2) 2-methoxy-3, 5-dichloro-4-aminobenzoic acid (formula IV)

To a 250mL four-necked flask, methyl 4- (acetylamino) -3, 5-dichloro-2-methoxybenzoate (formula III) (20.0g, 0.069mol), 20mL of ethanol, 100mL of water, and sodium hydroxide (8.7g, 0.22mol) were added, and the mixture was heated to reflux and reacted for 3 hours. Stopping heating, transferring the reaction solution into a 500mL bottle, stirring, starting dropwise adding 1M hydrochloric acid, adjusting the pH to about 5, cooling to below 12 ℃, stirring for 30min, performing suction filtration, adding 100mL of water into the filter cake again, pulping for 30min at below 20 ℃, performing suction filtration, washing the container and the filter cake with 20mL of water, and drying at 80 ℃ to obtain 15g of crude product, wherein the yield of the crude product is 92.9%.

Adding 242mL of absolute ethyl alcohol and 45mL of water into the solid, heating until the solid is clear, closing the heating, slowly cooling, crystallizing, cooling to below 20 ℃, stirring for 3 hours, carrying out suction filtration, washing a filter cake by using 20mL of 85% ethyl alcohol, and drying at 80 ℃ to obtain 12g of white crystals, wherein the yield is 74.3%, and the HPLC purity is 99.8%. m.p.255 deg.C decomposition, ESI-MS (M/z):258.01[ M + Na [)]⁺。

(3) N- (2-diethylaminoethyl) -2-methoxy-3, 5-dichloro-4-aminobenzamide (formula I)

To a 250mL three-necked flask were added 2-methoxy-3, 5-dichloro-4-aminobenzoic acid (formula IV) (9.6g,40.85mmol), CDI (7.23g, 44.63mmol), and DCM 100mL, heated to an inner temperature of 35 deg.C, and the reaction was allowed to proceed with incubation for 1.5 hours, followed by addition of N, N-diethylethylenediamine (5.18g, 44.63mmol) and refluxing for 1.5 hours. After-treatment, 100mL of DCM diluted reaction solution was added to the flask, 20mL of water was added, and the organic phase was washed with 20X 3 of water, separated, dried over anhydrous sodium sulfate, and concentrated to give 10.1g of pale yellow oil, yield 74.5%, and HPLC purity 99.8%. ESI-MS (M/z) 334.13[ M + H]⁺。

¹H-NMR(400MHz,DCl₃)：δ8.148(s,1H),8.006(s,1H),4.781(s,2H),3.862(s,3H),3.470～ 3.518(m,2H),2.543～2.643(m,6H),1.006～1.042(t,6H)。

Example 2:

(1)4- (acetylamino) -3, 5-dichloro-2-methoxybenzoic acid methyl ester (formula III)

A three-necked flask was charged with a compound of formula II (36g,0.14mol), DMF100mL, t-BuOCl (30.4g,0.28mol) heated to an internal temperature of 85 ℃ and allowed to react for 5 hours, the reaction mixture was poured into ice water, extracted with EA 100mL × 3 times, the combined organic phases were washed with water 100mL × 2 times, separated, dried over anhydrous sodium sulfate, concentrated to give 30.2g of a yellow solid, and recrystallized with THF/PE 5:16 to give 20.1g of an off-white solid, yield 49.3%, mp: 137 ℃ and 139 ℃, ESI-MS (M/z):291.98[ M + H]⁺。

(2) 2-methoxy-3, 5-dichloro-4-aminobenzoic acid (formula IV)

To a 250mL four-necked flask, methyl 4- (acetylamino) -3, 5-dichloro-2-methoxybenzoate (formula III) (20.0g, 0.069mol), 20mL of ethanol, 100mL of water, and sodium hydroxide (8.7g, 0.22mol) were added, and the mixture was heated to reflux and reacted for 3 hours. Stopping heating, transferring the reaction solution into a 500mL bottle, beginning dropwise adding 1M hydrochloric acid while stirring, adjusting the pH to about 4, cooling to below 12 ℃, stirring for 30min, performing suction filtration, adding 100mL of water again into the filter cake, pulping for 30min below 20 ℃, performing suction filtration, washing the container and the filter cake with 20mL of water, and drying at 80 ℃ to obtain 14g of crude product, wherein the yield of the crude product is 86.7%.

Adding 242mL of absolute ethyl alcohol and 45mL of water into the solid, heating until the solid is clear, closing the heating, slowly cooling, crystallizing, cooling to below 20 ℃, stirring for 3 hours, carrying out suction filtration, washing a filter cake by using 20mL of 85% ethyl alcohol, and drying at 80 ℃ to obtain 11g of white crystals, wherein the yield is 68.1%, and the HPLC purity is 99.6%. m.p.255 deg.C decomposition, ESI-MS (M/z):258.01[ M + Na [)]⁺。

(3) N- (2-diethylaminoethyl) -2-methoxy-3, 5-dichloro-4-aminobenzamide (formula I)

To a 250mL three-necked flask were added 2-methoxy-3, 5-dichloro-4-aminobenzoic acid (formula IV) (9.6g,40.85mmol), CDI (7.23g, 44.63mmol), and DCM 100mL, heated to an inner temperature of 35 deg.C, and the reaction was allowed to proceed with incubation for 1.5 hours, followed by addition of N, N-diethylethylenediamine (5.18g, 44.63mmol) and refluxing for 1.5 hours. After-treatment, 100mL of DCM diluted reaction solution was added to the flask, and 20mL of water was added, and the organic phase was washed with 20X 3 of water, separated, dried over anhydrous sodium sulfate, and concentrated to give 10g of pale yellow oil, yield 73.7%, and HPLC purity 99.5%. ESI-MS (M/z) 334.13[ M + H]⁺. The nuclear magnetic data are shown in example 1.

Example 3:

(1)4- (acetylamino) -3, 5-dichloro-2-methoxybenzoic acid methyl ester (formula III)

A three-necked flask was charged with the compound of formula II (36g,0.14mol), DMF100mL, NCS (37.4g,0.28mol), heated to an internal temperature of 85 ℃ and allowed to react for 5 hours while maintaining the temperature, the reaction mixture was poured into ice water, extracted with EA 100 mL. times.3 times, the combined organic phases were washed with water 100 mL. times.2 times, separated, dried over anhydrous sodium sulfate, concentrated to give a yellow solid 30.2g,recrystallization from THF/PE 5:20 gave 21.3g of an off-white solid in 52.3% yield, mp: 137 ℃ and 139 ℃, ESI-MS (M/z):291.98[ M + H]⁺。

(2) 2-methoxy-3, 5-dichloro-4-aminobenzoic acid (formula IV)

To a 250mL four-necked flask, methyl 4- (acetylamino) -3, 5-dichloro-2-methoxybenzoate (formula III) (20.0g, 0.069mol), 20mL of ethanol, 100mL of water, and sodium hydroxide (8.7g, 0.22mol) were added, and the mixture was heated to reflux and reacted for 3 hours. Stopping heating, transferring the reaction solution into a 500mL bottle, stirring, starting dropwise adding 1M hydrochloric acid, adjusting the pH to about 5, cooling to below 12 ℃, stirring for 30min, performing suction filtration, adding 100mL of water into the filter cake again, pulping for 30min at below 20 ℃, performing suction filtration, washing the container and the filter cake with 20mL of water, and drying at 80 ℃ to obtain 15.1g of crude product, wherein the yield of the crude product is 93.5%.

Adding 242mL of absolute ethyl alcohol and 45mL of water into the solid, heating until the solid is clear, closing the heating, slowly cooling, crystallizing, cooling to below 20 ℃, stirring for 3 hours, carrying out suction filtration, washing a filter cake by using 20mL of 85% ethyl alcohol, and drying at 80 ℃ to obtain 12g of white crystals, wherein the yield is 74.3%, and the HPLC purity is 99.8%. m.p.255 deg.C decomposition, ESI-MS (M/z):258.01[ M + Na [)]⁺。

(3) N- (2-diethylaminoethyl) -2-methoxy-3, 5-dichloro-4-aminobenzamide (formula I)

To a 250mL three-necked flask were added 2-methoxy-3, 5-dichloro-4-aminobenzoic acid (formula IV) (9.6g,40.85mmol), TsCl (8.51g, 44.63mmol), and DCM 100mL, heated to an inner temperature of 35 deg.C, and the reaction was allowed to proceed with incubation for 1.5 h, followed by addition of N, N-diethylethylenediamine (5.18g, 44.63mmol) and refluxing for 1.5 h. After-treatment 100mL of DCM diluted reaction solution was added to the flask, 20mL of water was added, and the organic phase was washed with 20X 3 of water, separated, dried over anhydrous sodium sulfate, and concentrated to give 8g of pale yellow oil with a yield of 59% and an HPLC purity of 99.0%. ESI-MS (M/z) 334.13[ M + H]⁺. The nuclear magnetic data are shown in example 1.

Example 4: detection of new metoclopramide dichlorine impurity

The sample solution is precisely weighed and taken as metoclopramide raw material with the weight of about 10mg, and is put into a10 ml measuring flask, and methanol is added: 10ml of water (1:2) was dissolved and diluted to the scale, and shaken up to obtain a sample solution.

Control solution the sample solution was measured precisely and diluted quantitatively with mobile phase to give a solution containing about 1. mu.g of sample per 1ml as a control solution.

Chromatographic conditions the column was Welch Xtimate-C8(5 μm, 4.6X 250 mm); 0.050mol/L potassium dihydrogen phosphate solution (0.2 ml N, N-dimethyl octylamine is added, and the pH value is adjusted to 4.0 by phosphoric acid) is taken as a mobile phase A, and acetonitrile is taken as a mobile phase B; the flow rate is 1 ml/min; the detection wavelength is 275 nm; the column temperature was 35 ℃ and elution was carried out in a linear gradient as shown in Table 1.

The applicability of the system requires that the theoretical plate number is not less than 4000 calculated according to a metoclopramide peak.

The determination method comprises precisely measuring the test solution and the reference solution, respectively injecting into a liquid chromatograph, and recording chromatogram until the retention time of main component chromatogram peak is 2 times.

TABLE 1 gradient elution procedure for related substances

Time (min)	A(％)	B(％)
			0	92	8
10	92	8
			15	90	10
40	70	30
			45	70	30
46	92	8
			55	92	8

TABLE 2 relative retention times and limits of the New Methoxychloropramine Dichloro impurity

Under the chromatographic conditions, the relative retention time shown by the new metoclopramide dichlorine impurity is 1.1, and the metoclopramide dichlorine impurity can be effectively separated from the metoclopramide bulk drug. The establishment of the impurity analysis method provides an effective means for monitoring the content of related substances of metoclopramide, and is more favorable for ensuring the product quality of metoclopramide and the medication safety of patients.

Test example:

the TA97, TA98, TA100 and TA102 are taken as test strains, and the new metoclopramide dichlorine impurity is taken as a sample to carry out a plate doping test, and the result shows that the mutation-causing ratio MR value is 2.1, and the impurity can be judged to be positive in mutation-causing by dose-response relation.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various changes and modifications can be made without departing from the inventive concept of the present invention, and these changes and modifications are all within the scope of the present invention.