CN111138506B

CN111138506B - Preparation method of isepamicin sulfate

Info

Publication number: CN111138506B
Application number: CN201911421083.0A
Authority: CN
Inventors: 汪炳英; 金志敏; 葛晶晶; 赵如慧; 李孙平; 顾勤城
Original assignee: Zhejiang Hongsheng Pharmaceutical Co ltd
Current assignee: Zhejiang Hongsheng Pharmaceutical Co ltd
Priority date: 2019-12-31
Filing date: 2019-12-31
Publication date: 2021-05-25
Anticipated expiration: 2039-12-31
Also published as: CN111138506A

Abstract

The invention discloses a method for preparing isopamicin sulfate, which comprises the steps of taking gentamicin B as a raw material, protecting some hydroxyl groups or amino groups needing to be removed from reaction by a boron reagent so as to ensure that the gentamicin B does not participate in the grafting reaction of (S) -isoserine to obtain an intermediate (III), reacting the intermediate (III) with a side chain active ester intermediate (II) containing (S) -isoserine to obtain an Intermediate (IV), wherein the structure of the intermediate is shown in figure 1, and hydrolyzing the intermediate (II) by using sulfuric acid to obtain the isopamicin sulfate; the synthesis method is simpler and more convenient, is beneficial to operation, has higher product yield and improves the industrial production efficiency.

Description

Preparation method of isepamicin sulfate

Technical Field

The invention relates to the technical field of compound synthesis and purification, in particular to a preparation method of isepamicin sulfate.

Background

Isopamicin (isepamicin) is a new semi-synthetic aminosugar-shake (Xixiaminoglycoside) antibiotic, which is obtained by introducing (S) -isoserine into amino group in gentamicin B (gentamiein B) structure, and the sulfate (trade name: Ikesha) is used clinically. It is mainly combined with 30S ribosome, so that it can inhibit the stationary phase of bacterial protein synthesis and can obtain the bactericidal action.

The ispamicin has good antibacterial effect on gram-negative bacilli such as most enterobacteriaceae bacteria, pseudomonas and acinetobacter, staphylococcus aureus and the like. The antibacterial effect of the medicine on serratia marcescens, aerobacter aerogenes, cloaca and klebsiella pneumoniae is obviously superior to that of amikacin, the antibacterial effect on pseudomonas, acinetobacter and staphylococcus aureus and coagulase negative staphylococcus are equivalent to or slightly superior to that of amikacin, and the medicine has good antibiotic after effect (PAE). The main characteristic is that it is stable to many kinds of inactivating enzyme produced by bacteria, so that it has less drug-resistant strain and can still be sensitive to other aminoglycoside drug-resistant people.

The prior aminoglycoside antibiotics have been on the decline trend in clinical application due to drug resistance and toxic and side effects, the first generation of antibiotics has gradually withdrawn from first-line medication, the isepamicin maintains and strengthens the advantages of the prior aminoglycoside antibiotics and reduces the toxic and side effects thereof, has the advantages of strong bactericidal activity, low drug resistance, small toxic and side effects, good antibiotic after-effect and the like, has about 90 percent of curative effect on lower respiratory tract infection caused by corresponding pathogenic bacteria, such as bronchitis, bronchiectasis infection, nosocomial pneumonia and the like, has become a new generation of effective antibacterial good drugs, and is widely applied to the treatment of various bacterial infections at home and abroad.

At present, a plurality of methods for synthesizing the isepamicin and the salts thereof exist, for example, gentamicin B is protected by 2-formyl mercapto benzothiazole and then connected with (S) -isoserine (CN 101469007A), gentamicin B is protected by trimethylsiloxyethyl carbonyl chloride and then connected with (S) -isoserine (CN 105254688A), gentamicin B and electrodeless zinc ion chelate and post amidation are connected with (S) -isoserine (CN 102093444), and the like have the defects of low yield, complex operation and expensive raw materials.

Disclosure of Invention

The invention aims to solve the defects of the prior art and provides a preparation method of isepamicin sulfate.

In order to realize the purpose, the invention provides a preparation method of isepamicin sulfate, which comprises the following steps: gentamicin B is used as a raw material, certain hydroxyl or amino groups which need to be eliminated are protected by a boron reagent and do not participate in the grafting reaction of (S) -isoserine to obtain an intermediate (III), the intermediate (III) reacts with a side chain active ester intermediate (II) containing (S) -isoserine and phthalic anhydride to obtain an Intermediate (IV), the structure of the intermediate is shown in figure 1, and then sulfuric acid is used for hydrolyzing to obtain isepamicin sulfate; the preparation method is characterized by comprising the following steps:

step 1: preparing a side chain active ester intermediate (II) by reacting N-hydroxyphthalimide with phthalimido- (S) isoserine in the presence of N, N' -Dicyclohexylcarbodiimide (DCC); the chemical structural formula of the intermediate (II) is as follows:

step 2: taking gentamicin B as an original raw material, adding a certain amount of solvent, reacting with a boron reagent and a polyhydroxy compound together under an alkaline condition to protect hydroxyl or amino which needs to be removed from the reaction, and obtaining an intermediate (III); the polyhydroxy compound is any one of glycerol, diglycerol, triglycerol and ethylene glycol, the boron reagent is boric acid or borax, and the chemical structural formula of the intermediate (III) is as follows:

and step 3: reacting the intermediate (III) with a side chain active ester intermediate (II) containing (S) -isoserine and phthalic anhydride to form an Intermediate (IV) protected by a borate ester derivative; the chemical structural formula of the Intermediate (IV) is as follows:

and 4, step 4: and acidifying the Intermediate (IV) by using a deprotection reagent and sulfuric acid to obtain a crude isepamicin sulfate (I), and recrystallizing for multiple times to obtain a fine product.

Further, in the step 1, the molar ratio of the (S) -isoserine to the phthalic anhydride and the N-hydroxyphthalimide is 1:1:1-1:2: 2.

Further, the reaction temperature in the step 1 is 50-120 ℃, and the reaction time is 3-5 h.

Further, in the step 2, the polyhydroxy compound is any one of glycerol, diglycerol, triglycerol and ethylene glycol, and the weight part of the polyhydroxy compound relative to gentamicin B is 10% -50%.

Further, the molar ratio of the gentamicin B and the boron reagent in the step 2 is 1:4-1:10, and the boron reagent is boric acid or borax.

Further, the reaction temperature in the step 2 is 30-65 ℃, and the reaction time is 3-10 h.

Further, the solvent in step 2 is water, and 10% sodium hydroxide is added to adjust the pH to 7.5 to 10.

Further, the molar ratio of the intermediate (III) described in step 3 to the side chain active ester intermediate (II) containing (S) -isoserine is 1:2 to 1: 10.

Further, the reaction temperature in the step 3 is 35-60 ℃, and the reaction time is 10-24 h.

Further, the reaction temperature in the step 4 is 40-70 ℃, and the reaction time is 2-6 h.

Further, the deprotection reagent in step 4 is 1-10% dilute sulfuric acid.

In the above synthesis steps, the boron reagent in step 2 protects the hydroxyl or amino groups from which the reaction is to be excluded, and most importantly, the steric hindrance on each group is affected differently. Due to the steric effect of the space structure of gentamicin B and each group, an intermediate of the borate derivative with a specific structure and the intermediate combined with the borate derivative is obtained, and the intermediate (III) of the compound is obtained by the reaction of gentamicin B and a boron reagent and is shown in figure 1.

In the above synthesis steps, the chemical environments of the amino groups at

positions

1 and 2 on the ring of the intermediate (III) in step 2 are different, the amino group at position 1 is affected by the amino group on the connecting ring, and the steric hindrance is larger than that of the amino group at position 2 on the same ring, so that the reaction of the amino group at position 1 with hydroxyl and boron reagent is more difficult; the steric hindrance of the amino on the 2-position is small, the reaction is easy, and the positions of the hydroxyl on the same ring and the hydroxyl on the interlinkage are closer, and the steric hindrance is smaller. Therefore, the steric hindrance of the amino group 1 is further enhanced by the addition of boron reagent due to the steric hindrance of the amino group 1 of the intermediate (III) in the step 3, and the side chain active ester intermediate (II) containing (S) -isoserine reacts with the amino group 2 to obtain the Intermediate (IV).

In the above experiment, the side chain active ester intermediate (II) containing (S) -isoserine in step 4 can be subjected to direct removal of its protecting group in a weak alkaline environment formed by a boron reagent, and then diluted sulfuric acid is added for removing a borate protecting group by an acidification reaction, so that the process is completed in one step.

Compared with the existing synthesis method of isepamicin sulfate and salts thereof, the synthesis method has the advantages that the special steric hindrance of reactants is generated, certain steric hindrance is generated by utilizing the one-time protection reaction of a boron reagent on polyhydroxy compounds, the intermediate (III) and the side chain active ester intermediate (II) containing (S) -isoserine are combined in a high selectivity mode, the operation is simpler and more convenient, the product yield is higher, and the industrial production efficiency is improved.

In the structure of the boric acid bis-polyol ester synthesized by boric acid, 3B-O bonds form a plane triangle, but the unhybridized 2p vacant orbitals easily accept lone pair electrons on oxygen atoms (or nitrogen atoms) in free hydroxyl groups on the ortho positions to form coordinate bonds, so that the valence electron configuration of boron atoms is induced to be changed into thermodynamically stable sp (p-type) bonds³The hybrid orbit is in a regular tetrahedron structure, and forms a semipolar boron spiro structure. The hydroxyl groups in the molecule of the boric acid bis-polyol ester are not free, but form semipolar combination with boron atoms. The intermediates contain active hydroxyl groups, so that the intermediates can continuously react with different functional groups to generate different types of intermediate products.

Boric acid and ortho hydroxyl groups have excellent high-selectivity bonding, a covalent bond is connected or an internal coordination complex is formed, a boron reagent reacts with amino to form the internal coordination complex, and after a polyhydroxy compound with amino reacts with the boron reagent, generated hydrogen ions and the amino perform a neutralization reaction to further promote the reaction of the boron reagent and the hydroxyl, so that the bonding between the boron reagent and the hydroxyl is more efficient and compact, the stability of the substance is improved, the boron reagent can be separated and removed under an acidic condition, and the operation is simple, convenient and efficient. Boric acid or borax substances are used for selectively protecting hydroxyl and amino in gentamicin B, and a new choice is provided for preparing isepamicin sulfate.

Drawings

FIG. 1 is a chemical equation of a compound obtained by reacting gentamicin B of the present invention with a boron reagent;

FIG. 2 is a chemical equation of the present invention for obtaining a side chain active ester intermediate (II) containing (S) -isoserine;

FIG. 3 is a chemical equation for gentamicin B of the present invention to produce intermediate (III);

FIG. 4 is a chemical equation for the preparation of Intermediate (IV) protected by a boronic ester derivative according to the present invention;

FIG. 5 shows the chemical equation of the present invention for acidifying dilute sulfuric acid to obtain isepamicin sulfate.

Detailed Description

The present invention will be further explained with reference to specific examples. In addition, "g" in each example is a weight unit of "g"; "h" is the time unit "hour"; "ml" is volume unit "ml"; "mg/L" is the unit of concentration "milligrams per liter"; in the examples, isepamicin sulfate refers to the product formed by sulfuric acid and isepamicin in an equimolar ratio, and n is 1 in fig. 5.

Example 1

A preparation method of isepamicin sulfate comprises the following steps:

step 1: in the presence of N, N' -Dicyclohexylcarbodiimide (DCC), N-hydroxyphthalimide and phthalimido- (S) isoserine are reacted to prepare a side chain active ester intermediate (II), which comprises the following steps:

adding 300.0ml solvent dioxane into a 500.0ml three-necked bottle, magnetically stirring, adding 50.0g of (S) -isoserine and 150.0g of phthalic anhydride, heating and refluxing for 2.0h, removing generated water by a water separator, adding 100g of N-hydroxyphthalimide and 20.0g of N, N' -dicyclohexylcarbodiimide, continuously refluxing for 2.0h, stopping heating, naturally cooling to room temperature, and filtering to obtain 232.3g of the side chain active ester intermediate (II) product.

Step 2: taking gentamicin B as an original raw material, adding a certain amount of solvent, reacting with a boron reagent and a polyhydroxy compound together to protect hydroxyl and amino to obtain an intermediate (III), which is as follows:

in a 250.0ml three-necked flask, 40.0g of gentamicin B and 150.0ml of water were added, followed by mechanical stirring, 20.5g of boric acid and 6.8g of ethylene glycol were added, pH was adjusted to 10.0 with 10% sodium hydroxide, and the mixture was stirred at 30 ℃ for 6.0 hours, and then the mixture was cooled to room temperature by cooling to obtain 59.8g of the sodium salt product of intermediate (iii).

And step 3: and reacting the intermediate (III) with a side chain active ester intermediate (II) containing (S) -isoserine and phthalic anhydride to obtain an Intermediate (IV) protected by a boric acid derivative, wherein the Intermediate (IV) comprises the following specific steps:

59.8g of the sodium salt of intermediate (III) and 150.0g of intermediate (II) obtained in the above reaction were put into a 500.0ml three-necked flask, 150.0ml of methanol was added to form a suspension, and after stirring at 50 ℃ for 16.0 hours, heating was stopped and the temperature was naturally lowered to room temperature, and then, 61.1g of the sodium salt product of Intermediate (IV) was obtained by filtration.

And 4, step 4: and acidifying the Intermediate (IV) by using a deprotection reagent with sulfuric acid to obtain a crude product, and recrystallizing the crude product for multiple times to obtain the isepamicin sulfate (I), wherein the details are as follows:

in a 250.0ml beaker, slowly dripping 10% dilute sulfuric acid into 61.1g of the sodium salt of the Intermediate (IV) obtained at 40 ℃ until the sodium salt is acidic, fully stirring by magnetic force, carrying out suction filtration to obtain a crude isepamicin sulfate product, dissolving the crude isepamicin product in water, then recrystallizing for multiple times, and filtering to obtain 40.7g of a refined isepamicin sulfate product.

Measuring the content of isepamicin sulfate by HPLC-evaporative light scattering detection method, wherein the chromatographic column is YMC-pack ODS AM (4.6mm × 250mm,3 μm); the mobile phase is acetonitrile (99:1) which is an aqueous solution containing sodium hexanesulfonate, glacial acetic acid and sodium sulfate, the column temperature is 35 ℃, the flow rate is 0.8m L/min, the post-column derivatization reagent solution is an o-phthalaldehyde solution, the flow rate is 0.8mL/min, the derivatization reaction temperature is 45 ℃, the fluorescence excitation wavelength is 360nm, and the emission wavelength is 440 nm. The purity of the isepamicin sulfate refined product is 99.1% by HPLC detection. The yield of isepamicin sulfate was 73% based on the data calculation of gentamicin B.

Example 2

This example is the same as example 1 except for the following parameters in step 2: adding 40.0g of gentamicin B and 100.0ml of water into a 250.0ml three-necked bottle, mechanically stirring, adding 189.7g of borax decahydrate and 10.0g of glycerol, adjusting the pH value to 10.0 by using 10% sodium hydroxide, stirring at 40 ℃ for 6.0h, stopping heating, naturally cooling to room temperature to obtain an intermediate (III) in the step 2, reacting to obtain a crude isepamicin sulfate, and repeatedly recrystallizing the crude isepamicin sulfate to obtain 41.3g of a refined isepamicin sulfate. The purity of the isepamicin sulfate refined product is 99.2% by HPLC detection. The yield of isepamicin sulfate is 74% by taking gentamicin B as a data calculation basis.

Example 3

This example is the same as example 1 except for the following parameters in step 2: adding 40.0g of gentamicin B and 120.0ml of water into a 250.0ml three-necked bottle, mechanically stirring, adding 40.9g of boric acid and 14.5g of diglycerol, adjusting the pH value to 10.0 by using 10% sodium hydroxide, stirring at 50 ℃ for 6.0h, stopping heating, naturally cooling to room temperature to obtain an intermediate (III) in the step 2, reacting to obtain a crude isepamicin sulfate, and repeatedly recrystallizing the crude isepamicin sulfate to obtain 43.5g of a refined isepamicin sulfate. The purity of the isepamicin sulfate refined product is 99.1% by HPLC detection. The yield of isepamicin sulfate was 78% based on the data calculation of gentamicin B.

Example 4

This example is the same as example 1 except for the following parameters in step 2: adding 40.0g of gentamicin B and 90.0ml of water into a 250.0ml three-necked bottle, mechanically stirring, adding 316.2g of borax decahydrate and 18.1g of triglycerin, adjusting the pH value to 10.0 by using 10% sodium hydroxide, stirring for 6.0h at 60 ℃, stopping heating, naturally cooling to room temperature to obtain an intermediate (III) in the step 2, reacting to obtain a crude isepamicin sulfate, and repeatedly recrystallizing the crude isepamicin sulfate to obtain 42.4g of a refined isepamicin sulfate. The purity of the isepamicin sulfate refined product is 99.1% by HPLC detection. The yield of isepamicin sulfate is 76% by taking gentamicin B as a data calculation basis.

The yield of the isepamicin sulfate prepared by the method reaches over 70 percent, and the purity can reach 99 percent.

In the invention, gentamicin B reacts with a boron reagent to obtain a compound, namely, an intermediate (III) with a molecular formula of [ R ═ H or-CH₂OH, or-OCH₂CH(OH)CH₂OH, or-OCH₂CH(OH)CH₂OCH₂CH(OH)CH₂OH](ii) a Chemical equation for gentamicin B to produce intermediate (iii): [ R ═ H, or-CH₂OH, or-OCH₂CH(OH)CH₂OH, or-OCH₂CH(OH)CH₂OCH₂CH(OH)CH₂OH](ii) a Chemical equation for the preparation of intermediate (iv) protected by boronic ester derivative: [ R ═ H, or-CH₂OH, or-OCH₂CH(OH)CH₂OH, or-OCH₂CH(OH)CH₂OCH₂CH(OH)CH₂OH](ii) a Chemical equation of sulfuric acid acidification to obtain isepamicin sulfate [ R ═ H, or-CH₂OH, or-OCH₂CH(OH)CH₂OH, or-OCH₂CH(OH)CH₂OCH₂CH(OH)CH₂OH, n-1 to 2]

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.

Claims

1. A preparation method of isepamicin sulfate comprises the following steps: gentamicin B is taken as a raw material, hydroxyl or amino at certain specific positions is protected by a boron reagent so as not to participate in the grafting reaction of (S) -isoserine to obtain an intermediate (III), then the intermediate (III) reacts with a side chain active ester intermediate (II) containing (S) -isoserine and phthalic anhydride to obtain an Intermediate (IV), and then sulfuric acid is used for hydrolysis to obtain the isepamicin sulfate; the preparation method is characterized by comprising the following steps:

2. The method for preparing isepamicin sulfate according to claim 1, wherein the molar ratio of (S) -isoserine to phthalic anhydride and N-hydroxyphthalimide in step 1 is 1:1:1 to 1:2: 2.

3. The method for preparing isepamicin sulfate according to claim 1, wherein the reaction temperature in step 1 is 50-120 ℃ and the reaction time is 3-5 h.

4. The method for preparing isepamicin sulfate according to claim 1, wherein the mass fraction of the polyhydroxy compound relative to gentamicin B is 10% -50%.

5. The method for preparing isepamicin sulfate according to claim 1, wherein the molar ratio of gentamicin B to the boron reagent in step 2 is 1:4 to 1: 10.

6. The method for preparing isepamicin sulfate according to claim 1, wherein the reaction temperature in step 2 is 30-65 ℃ and the reaction time is 3-10 h.

7. The method for preparing isepamicin sulfate according to claim 1, wherein the solvent in step 2 is water, and 10% sodium hydroxide is added to adjust the pH to 7.5-10.

8. The method for preparing isepamicin sulfate according to claim 1, wherein the molar ratio of the intermediate (III) to the side chain active ester intermediate (II) containing (S) -isoserine in the step 3 is 1:2 to 1: 10.

9. The method for preparing isepamicin sulfate according to claim 1, wherein the reaction temperature in step 3 is 35-60 ℃ and the reaction time is 10-24 h.

10. The method for preparing isepamicin sulfate according to claim 1, wherein the reaction temperature in step 4 is 40-70 ℃ and the reaction time is 2-6 h.

11. The method of claim 1, wherein the deprotection reagent in step 4 is 1-10% dilute sulfuric acid.