CN109776540B

CN109776540B - Preparation method of sapropterin hydrochloride

Info

Publication number: CN109776540B
Application number: CN201711131646.3A
Authority: CN
Inventors: 刘素云; 李克让
Original assignee: Beijing Kailai Tiancheng Medicine Technology Co ltd; Beijing Qihui Biomedical Co ltd
Current assignee: Beijing Kailai Tiancheng Medicine Technology Co ltd; Beijing Qihui Biomedical Co ltd
Priority date: 2017-11-15
Filing date: 2017-11-15
Publication date: 2021-07-06
Anticipated expiration: 2037-11-15
Also published as: CN109776540A

Abstract

The invention relates to a preparation method of sapropterin hydrochloride represented by a formula (I), which comprises the steps of taking 5-deoxyarabinose as a raw material, carrying out acetylation reaction in the presence of acetic anhydride to obtain an intermediate DL-1, and reacting DL-1 with phenylhydrazine under the catalysis of acetic acid to obtain an intermediate DL-2; closing the ring of DL-2 and amiloride sulfate under the catalysis of anhydrous lithium perchlorate to obtain an intermediate DL-3, and directly oxidizing the intermediate DL-3 by an iodine simple substance without purification to obtain an intermediate DL-4; hydrolyzing DL-4 with potassium hydroxide to obtain L-biopterin (DL-5); and reducing the L-biopterin by using a platinum catalyst, and salifying to obtain the sapropterin hydrochloride. The route has simple operation, high yield, total yield of the route of more than 70 percent, purity of the final product of more than 99.5 percent, low energy consumption and suitability for industrial production.

Description

Preparation method of sapropterin hydrochloride

Technical Field

The invention relates to a preparation method of Sapropterin hydrochloride (Saproperine dihydrate), belonging to the field of medicine synthesis.

Background

Phenylketonuria (PKU) is an autosomal recessive genetic disorder, and phenylalanine metabolism is disturbed due to hepatic phenylalanine hydroxylase deficiency or deficiency in tetrahydrobiopterin synthase and dihydrobiopterin reductase. Sapropterin hydrochloride is currently the only therapeutic agent for PKU, it is artificially synthesized tetrahydrobiopterin (BH4), a coenzyme for three aromatic amino acid hydroxylases, phenylalanine, tyrosine, and tryptophan, and treatment of PKU with sapropterin hydrochloride is known as BH4 replacement therapy.

Sapropterin hydrochloride, chemically (6R) -2-amino-6- [ (1R, 2S) -1, 2-dihydroxypropyl ] -5, 6, 7, 8-tetrahydro-4 (1H) -pteridine dihydrochloride, having the structural formula (I):

（I）

the current routes commonly used for sapropterin hydrochloride (Helvetica Chimica Acta, 1985, 68, 1639-1643 and US2015291590A 1) are as follows:

according to the method, 5-deoxy-L-arabinose (DL-SMA) is used as a raw material, and is condensed with phenylhydrazine to prepare a phenylhydrazone compound (DL-6), then acetylation is carried out to obtain 2,3, 4-O-triacetyl-5-deoxy-L-arabinophenylhydrazone (DL-2), and the phenylhydrazone and 2,4, 5-triamino-6-hydroxypyrimidine sulfate (DL-SMB) are subjected to cyclization, oxidation, hydrolysis and hydrogenation to obtain a final product, namely sapropterin hydrochloride. The disadvantage of this route is that the DL-6 compound is unstable and the anilino group is easily removed during the next protecting group addition step, resulting in the formation of a large number of impurities. The HPLC profile of the final product sapropterin hydrochloride prepared according to the route described in US2015291590A1 is shown in the specification, FIG. 3, where it can be seen that the final product has a large impurity which is difficult to remove. In addition, column chromatography is carried out in the process of treating the intermediates DL-3 and DL-4, so that the method is not suitable for industrial production.

In the patent CN101959891, when the intermediate DL-5 is synthesized, a two-phase mixed solution is utilized for hydrolysis, impurities are left in organic phase n-butyl alcohol, a water phase contains a product, the purity is high although the yield is low, and the organic solvent n-butyl alcohol which is regurgitating and inflammable is used.

In WO2016189542A1, when intermediate DL-5 is synthesized, intermediate DL-5 is purified by a conventional method of adjusting the pH of an aqueous solution by utilizing the property that the compound can form a potassium salt, and the operation is complicated and the yield is low.

Therefore, the existing routes have various defects, and a more optimized route is needed for producing the medicine.

Disclosure of Invention

Aiming at the problems in the prior art, the inventor modifies the process route and optimizes the purification and refining method of the intermediate through a large number of condition experiments, takes DL-SMA (5-deoxy arabinose) as a raw material, firstly acetylates, then reacts with phenylhydrazine under the catalysis of acid to carry out Schiff base reaction to obtain DL-2, then reacts with aminopyrimidine (DL-SMB) to carry out ring closing to obtain intermediate state DL-3, oxidizes the intermediate to obtain important intermediate DL-4 through a one-pot method, directly hydrolyzes the intermediate in aqueous solution without purification to obtain intermediate DL-5, then adjusts the pH value of the aqueous solution, and finally carries out ion resin purification to obtain the final product.

Specifically, the invention relates to a preparation method of sapropterin hydrochloride represented by formula (I), specifically, sapropterin hydrochloride is obtained through reaction steps a-e represented by the following formula (II):

（I）

（II）

a) 5-deoxy arabinose (DL-SMA) is taken as a raw material, and an intermediate DL-1 is obtained through acetylation reaction;

b) reacting DL-1 with phenylhydrazine under the catalysis of acid to obtain an intermediate DL-2;

c) closing the ring of DL-2 and the amino pyridine sulfate to obtain an intermediate DL-3, and directly oxidizing without purification to obtain an intermediate DL-4;

d) hydrolyzing DL-4 to obtain L-biopterin (DL-5);

e) and carrying out hydrogenation reduction and salification on the L-biopterin to obtain the sapropterin hydrochloride.

The preferred preparation process according to the invention, wherein the reaction temperature in step a is from 0 to 20 ℃.

The production method of the present invention is preferable, wherein the initial pH of the reaction solution of the step b is controlled to 3 to 7.

The preparation method of the present invention is preferable, wherein the catalyst of the ring closing process of step c is one selected from perchloric acid, perchlorate, and an aqueous solution of sodium hydrosulfite and acetate.

Preferably, in the preparation method of the present invention, the oxidant in the oxidation step in step c is elemental iodine or hydrogen peroxide.

The preferred preparation method of the present invention, wherein the hydrolysis process of step d uses strong acid or strong base.

Preferred preparation processes according to the invention, wherein the purification process of step d uses ion exchange resins.

The preparation method of the present invention is preferred, wherein the catalyst hydrogenated in step e is selected from one of palladium carbon, platinum black and platinum oxide.

Preferred preparation process according to the invention, wherein the hydrogenation in step e is carried out at a pressure of from 2MPa to 4 MPa.

The preparation method of the invention is preferable, wherein the most preferable preparation method comprises the following steps: performing acetylation reaction on 5-deoxy arabinose (DL-SMA) in the presence of acetic anhydride to obtain an intermediate DL-1; reacting DL-1 with phenylhydrazine under the catalysis of acetic acid to obtain an intermediate DL-2; closing the ring of DL-2 and amiloride sulfate under the catalysis of anhydrous lithium perchlorate to obtain an intermediate DL-3, and directly oxidizing the intermediate DL-3 by an iodine simple substance without purification to obtain an intermediate DL-4; hydrolyzing DL-4 with potassium hydroxide to obtain L-biopterin (DL-5); and reducing the L-biopterin by using a platinum catalyst, and salifying to obtain the sapropterin hydrochloride.

The preparation method of sapropterin hydrochloride has the following advantages: firstly, in the steps a and b, 5-deoxy arabinose is firstly acetylated and then reacts with phenylhydrazine, so that an unstable intermediate DL-6 is prevented from being generated, and the occurrence of side reactions in the next step is reduced; secondly, a one-pot method is used in the synthesis process of the intermediate DL-4, so that the flow and process time is reduced; furthermore, the refining of the intermediate DL-3 and DL-4 is reduced, the synthesis period is shortened, the energy consumption is reduced, and finally, in the synthesis of the intermediate DL-5, water is used as a solvent, so that the use of n-butyl alcohol is avoided, and the method is environment-friendly; in the purification process of the intermediate DL-5, the intermediate DL-5 is refined by ion exchange resin, and the purity of the obtained product is high and is beneficial to improving the purity of the final product. The whole route is simple and convenient to operate, the yield is high, the total yield of the route is more than 70%, the purity of a final product is more than 99.5%, the energy consumption is low, and the method is suitable for industrial production.

Description of the drawings:

FIG. 1 is an HPLC plot of intermediate DL-5 prepared according to example 5 of the present invention.

FIG. 2 is a HPLC chart of the final product sapropterin hydrochloride prepared in example 8 according to the present invention.

Figure 3 is an HPLC diagram of the final product sapropterin hydrochloride prepared according to the route described in patent US2015291590a 1.

Detailed Description

The present invention is further illustrated below with reference to specific examples. The present invention includes, but is not limited to, the following examples.

Example 1 Synthesis of DL-1:

adding DL-SMA (134 g, 1.0 mol) and ethyl acetate (1.0L, 24.4 g) in sequence into a reaction vessel, cooling to 10-15 ℃, dropwise adding acetic anhydride (326.7 g, 3.2 mol), controlling the internal temperature to 15-20 ℃, controlling the reaction temperature to 0-20 ℃, and monitoring by TLC until the reaction is finished. And (3) post-treatment: quenching with saturated aqueous sodium carbonate solution, collecting the organic phase after separation, extracting the aqueous phase with ethyl acetate (500 mL 2), combining the organic phases, washing with saturated aqueous sodium carbonate solution (400 mL 1), collecting the organic phase, spin-drying, recovering ethyl acetate to obtain light yellow oily substance DL-1 (260 g), and directly carrying out the next reaction.

Example 2 Synthesis of DL-2:

DL-1 (260 g) obtained in the above reaction and 900mL of water are added into a reaction vessel, acetic acid is added dropwise to adjust the pH value to 3-7, and then phenylhydrazine (118.8 g, 1.1mol, 1.1 eq) is added, stirred and reacted at room temperature under the protection of nitrogen overnight. TLC monitoring, after the reaction is finished, the reaction solution is extracted twice by ethyl acetate (500 mL x 2), organic phases are combined, dried by anhydrous sodium sulfate, filtered to remove a drying agent, and dried by spinning to obtain yellow oily substance DL-2 (340 g), and the next reaction is directly carried out.

Example 3 Synthesis of DL-4 method 1:

DL-2 (181 g, 0.51 mol) and 600mL of methanol were added to the reaction vessel, and the mixture was stirred until the total amount was dissolved. Anhydrous lithium perchlorate (1.8 g, 0.187 mol) was added and the reaction stirred for 30 minutes. The temperature was controlled at 30. + -. 5 ℃ and the aqueous solution of DL-SMB (151 g, 0.63 mol) in sodium hydroxide prepared in advance was added. Under the protection of nitrogen, the temperature is raised to reflux, the reaction is carried out overnight, and TLC monitoring is carried out until the reaction is finished. And (3) cooling to 10 +/-5 ℃, dropwise adding a methanol (600 mL) solution dissolved with an iodine simple substance (328 g, 1.29 mol), reacting at room temperature after dropwise adding, and monitoring by TLC until the reaction is finished. Filtration, rinsing with methanol and then water washing, dried the resulting solid to constant weight at 50 ℃ to give DL-4 as a light brown solid (300 g).

Example 4 Synthesis of DL-4 method 2:

DL-2 (23 g, 66 mmol), ethyl acetate 230mL, and pyridine 95.8mL were added to the reaction vessel and stirred until completely dissolved. An aqueous solution (100 mL) of sodium hydrosulfite (1.7 g, 0.010 mol) and sodium acetate (12.4 g, 0.151 mol) was added and stirred for 30 minutes. The temperature was controlled at 30. + -. 5 ℃ and a previously prepared aqueous solution (125 mL) of DL-SMB (18.4 g, 0.077 mol) was added. Under the protection of nitrogen, the temperature is raised to reflux, the reaction is carried out overnight, and TLC monitoring is carried out until the reaction is finished. And (3) cooling to 10 +/-5 ℃, dropwise adding a hydrogen peroxide solution (30 percent, 82 g), reacting at room temperature after dropwise adding, and monitoring by TLC until the reaction is finished. Filtration, rinsing with methanol and then water washing, dried the resulting solid to constant weight at 50 ℃ to give DL-4 (20 g).

Example 5 Synthesis of DL-5 method 1:

adding potassium hydroxide (164 g, 2.48 mol) and water (700 mL) into a reaction vessel, stirring until all the potassium hydroxide and water are dissolved, cooling to room temperature, adding DL-4 (157.1 g, 0.486 mol), stirring until all the DL-4 is dissolved, and heating to 40 +/-5 ℃ for reaction. TLC monitored until the reaction was complete. Stopping heating and cooling. 3N HCl is added dropwise to adjust the pH value to 7-8, and the solution is purified by ion exchange resin to remove salts and other impurities. Rotovap to dryness to give a pale yellow solid (102 g, 0.43mol, yield 88.5%).

Example 6 Synthesis of DL-5 method 2:

water (700 ml) and concentrated hydrochloric acid (205 ml) were added to a reaction vessel, followed by stirring, DL-4 (157.1 g, 0.486 mol) was added thereto at room temperature, followed by stirring until the total amount was dissolved, and the temperature was raised to 60 ℃. TLC monitored until the reaction was complete. Stopping heating and cooling. Separating, collecting water phase, adding 3N sodium hydroxide aqueous solution dropwise to adjust pH to 7-8, purifying with ion exchange resin, and removing salt and other impurities. Rotovap to dryness to give a pale yellow solid (98 g, 41.3mol, yield 85.2%).

From examples 1-6, the total yield from DL-SMA to DL-5 was about 85% or more.

Example 7 synthesis of sapropterin hydrochloride method 1:

to the reaction vessel were added DL-5 (20 g, 0.084 mol), water (200 mL), dipotassium hydrogen phosphate (7.2 g), and 10M aqueous potassium hydroxide was added to adjust the pH to 12 with substantially complete dissolution of DL-5. Transferring the mixture into a 2L hydrogenation kettle, adding anhydrous palladium carbon (5 g), replacing with hydrogen for three times, then hydrogenating to 4MPa, reacting at room temperature for 24h, and monitoring by HPLC until the reaction is finished. Filtering to remove the catalyst, collecting the filtrate, dropwise adding concentrated hydrochloric acid, adjusting the pH to 1, carrying out rotary evaporation until the residual solution is about 50mL, adding methanol 160mL, stirring for 30min, filtering, collecting the filtrate, carrying out rotary evaporation until the residual solution is about 30mL, adding 66mL of concentrated hydrochloric acid, then adding 100mL of ethanol, precipitating a solid, filtering, carrying out leaching with ethanol, collecting the solid, and drying to obtain 17.5g of white crystal sapropterin hydrochloride, wherein the yield is 86.4% and the ee value is 99%.

Example 8 synthesis of sapropterin hydrochloride method 2:

DL-5 (20 g, 0.084 mol), water (200 mL) and 25% aqueous tetraethylammonium hydroxide were added to the reaction vessel to adjust the pH to 12 with substantially complete dissolution of DL-5. Transferring the mixture into a 2L hydrogenation kettle, adding platinum dioxide (2.0 g), replacing the mixture with hydrogen for three times, then hydrogenating the mixture to 2MPa, reacting the mixture at room temperature for 24 hours, and monitoring by HPLC (high performance liquid chromatography) until the reaction is finished. The catalyst was removed by filtration, the filtrate was collected, concentrated hydrochloric acid was added, the pH was adjusted to 1, the solvent was spin-dried, absolute ethanol (2000 mL) was added, stirring was carried out for 1 hour, and then filtration, the filtrate was collected, and spin-drying was carried out to obtain 22g of a reddish brown oil. 66mL of concentrated HCl (10N) was added, heated to complete dissolution, ethanol (220 mL) was added dropwise to precipitate a solid, which was filtered, rinsed with ethanol, collected and dried to give 17.9g of sapropterin hydrochloride as white crystals, in 88.3% yield and 99% ee. The HPLC chart of the final product sapropterin hydrochloride is shown in the attached figure 2 of the specification.

Claims

1. A process for producing sapropterin hydrochloride represented by formula (I), characterized in that sapropterin hydrochloride is obtained by reaction steps a to e represented by the following formula (II):

a) sequentially adding DL-SMA, ethyl acetate and 4-dimethylaminopyridine into a reaction container, cooling to 10-15 ℃, dropwise adding acetic anhydride, controlling the internal temperature to be 15-20 ℃, controlling the reaction temperature to be 0-20 ℃ after dropwise adding, and monitoring by TLC (thin layer chromatography) until the reaction is finished; obtaining a light yellow oily substance DL-1, and directly carrying out the next reaction;

b) adding DL-1 and water obtained in the previous step into a reaction container, dropwise adding acetic acid to adjust the pH value to 3-7, then adding phenylhydrazine, stirring and reacting at room temperature under the protection of nitrogen overnight, and monitoring by TLC until the reaction is finished; obtaining a yellow oily substance DL-2, and directly carrying out the next reaction;

c) adding DL-2 and methanol into a reaction container, stirring until all the DL-2 and the methanol are dissolved, adding anhydrous lithium perchlorate, and stirring for reacting for 30 minutes; controlling the temperature to be 30 +/-5 ℃, adding DL-SMB, sodium hydroxide and water, heating to reflux under the protection of nitrogen, reacting overnight, and monitoring by TLC until the reaction is finished; cooling to 10 +/-5 ℃, adding methanol and iodine, reacting at room temperature after dripping, monitoring by TLC (thin layer chromatography) until the reaction is finished, filtering, leaching by using methanol, washing by using water, and drying the obtained solid at 50 ℃ to constant weight to obtain light brown solid DL-4;

d) adding potassium hydroxide and water into a reaction container, stirring until the potassium hydroxide and the water are completely dissolved, cooling to room temperature, adding DL-4, stirring until the potassium hydroxide and the water are completely dissolved, heating to 40 +/-5 ℃ for reaction, monitoring by TLC (thin layer chromatography) until the reaction is finished, stopping heating, cooling, dropwise adding 3N HCl to adjust the pH value to 7-8, purifying the solution by using ion exchange resin, and removing salt and other impurities; rotary steaming to dryness to obtain light yellow solid;

e) adding DL-5 and water into a reaction vessel, adding 25% tetraethylammonium hydroxide aqueous solution, adjusting the pH value to 12, and completely dissolving DL-5; transferring the mixture into a hydrogenation kettle, adding platinum dioxide, performing hydrogen replacement for three times, then, hydrogenating to 2MPa, reacting at room temperature for 24 hours, and monitoring by HPLC (high performance liquid chromatography) until the reaction is finished; filtering to remove catalyst, collecting filtrate, adding concentrated hydrochloric acid, adjusting pH to 1, spin-drying solvent, adding anhydrous ethanol, stirring for 1 hr, filtering, collecting filtrate, and spin-drying to obtain reddish brown oily substance; adding concentrated hydrochloric acid, heating to dissolve completely, dripping ethanol, precipitating solid, filtering, leaching with ethanol, collecting solid, and oven drying to obtain white crystal sapropterin hydrochloride.