阅读说明：本技术 一种2,3-O-异亚丙基-D-核糖酸-γ-内酯的重结晶方法 (Recrystallization method of 2, 3-O-isopropylidene-D-ribonic acid-gamma-lactone ) 是由 邵仲 周玉宝 吴尧 黄鑫 单环宇 许杭梁 蒋东栋 于 2021-09-01 设计创作，主要内容包括：本发明提供了一种2,3-O-异亚丙基-D-核糖酸-γ-内酯的重结晶方法,包含以下步骤：a、将含有2,3-O-异亚丙基-D-核糖酸-γ-内酯的粗品溶于酯类溶剂得到含有2,3-O-异亚丙基-D-核糖酸-γ-内酯的溶液；b、在含有2,3-O-异亚丙基-D-核糖酸-γ-内酯的溶液中加入反溶剂后降温至析晶温度析出固体；c、从固体中筛选析出颗粒状的晶体。本发明的方法操作简单,适合大规模生产；得到的产物纯度、产率高。(The invention provides a recrystallization method of 2, 3-O-isopropylidene-D-ribonic acid-gamma-lactone, which comprises the following steps: a. dissolving a crude product containing 2, 3-O-isopropylidene-D-ribonic acid-gamma-lactone in an ester solvent to obtain a solution containing 2, 3-O-isopropylidene-D-ribonic acid-gamma-lactone; b. adding an antisolvent into a solution containing 2, 3-O-isopropylidene-D-ribonic acid-gamma-lactone, cooling to a crystallization temperature, and precipitating a solid; c. and screening out granular crystals from the solid. The method is simple to operate and suitable for large-scale production; the obtained product has high purity and yield.)

1. A recrystallization method of 2, 3-O-isopropylidene-D-ribono-gamma-lactone is characterized in that:

comprises the following steps:

a. dissolving a crude product containing 2, 3-O-isopropylidene-D-ribonic acid-gamma-lactone in an ester solvent to obtain a solution containing 2, 3-O-isopropylidene-D-ribonic acid-gamma-lactone;

b. adding an antisolvent into a solution containing 2, 3-O-isopropylidene-D-ribonic acid-gamma-lactone, cooling to a crystallization temperature, and precipitating a solid;

c. and screening out granular crystals from the solid.

2. The recrystallization method according to claim 1, wherein:

the temperature is reduced to the crystallization temperature before the temperature is reduced to the crystallization temperature to culture the crystal nucleus.

3. A recrystallization method according to claim 2, wherein:

after completion of the nucleation culture, an anti-solvent is added.

4. The recrystallization method according to claim 1, wherein:

the anti-solvent is an alkane solvent; preferably, the anti-solvent is an alkane solvent with less than 16 carbon atoms, preferably n-heptane, n-hexane, cyclohexane and petroleum ether, and more preferably n-hexane.

5. The recrystallization method according to claim 1, wherein:

the ester solvent is one or more of ethyl acetate, propyl acetate and tert-butyl acetate, and ethyl acetate is preferred.

6. The recrystallization method according to claim 5, wherein:

the ratio of the volume (ml) of the ester solvent to the mass (g) of the crude product is greater than 1: 1 (ml: g); preferably greater than 1: 1 (ml: g), not higher than 4: 1 (ml: g).

7. The recrystallization method according to claim 6, wherein:

the ratio of the volume of the anti-solvent to the volume of the ester solvent is not higher than 1: 1; preferably, not higher than 1: 1, not less than 1: 3.

8. the recrystallization method according to claim 7, wherein:

the crystallization temperature is not higher than 25 ℃.

9. The recrystallization method according to claim 8, wherein:

the crystallization temperature is-5 to 25 ℃; preferably 5 ℃ below zero to 10 ℃; more preferably 0 deg.c.

10. A recrystallization method according to claim 9, wherein:

the crystallization time is not less than 1 h; preferably not less than 2 h; preferably not less than 3 h; preferably not less than 4 h.

Technical Field

The invention relates to the technical field of recrystallization, in particular to a recrystallization method of 2, 3-O-isopropylidene-D-ribonic acid-gamma-lactone.

Background

In recent years, mRNA drugs have attracted much attention as an emerging field of medicine. With the advent of new crown mRNA vaccines, the new crown mRNA vaccines become popular in the current medical field due to the characteristics of economy, flexibility, high efficiency and easiness in large-scale production. In order to solve the immunogenicity problem of mRNA drugs, the prior art will use some chemically modified nucleosides (e.g. 5-methylcytosine nucleoside (m5C), pseudouridine (Ψ), etc.) instead of natural nucleosides, which will not affect or even improve the translation efficiency while reducing the immunogenicity of the drug. The main structure of these nucleosides is D- (+) -ribose, introduced by the intermediate 2, 3-O-isopropylidene-D-ribono-gamma-lactone. In the prior art, the Synthesis method disclosed in "A convention, effective and Production-Scale Synthesis of a Protected l-Lyxolactone Derivative" by Batra H, Moriarty R M, Penmasta R et al, which is a reaction of D- (+) -ribono-gamma-lactone with acetone under the catalysis of sulfuric acid.

The product obtained by the method is separated by a chromatographic column to obtain two products, and the two products are subjected to nuclear magnetic analysis to obtain spectrograms shown in figures 1 and 2, wherein figure 1 is a target product, figure 2 is impurities, and the final product contains impurities of isomers in addition to the target compound by combining a mass spectrogram (figure 3) of the impurities.

The presence of such impurities can affect subsequent reactions and consume more material, which is not conducive to scale-up. However, the impurities of the isomers are difficult to separate and purify, and a chromatographic column is required for separation, which undoubtedly increases the production cost.

Disclosure of Invention

In order to overcome the above problems, the present invention provides a method for recrystallizing 2, 3-O-isopropylidene-D-ribono- γ -lactone, comprising the steps of:

a. dissolving a crude product containing 2, 3-O-isopropylidene-D-ribonic acid-gamma-lactone in an ester solvent to obtain a solution containing 2, 3-O-isopropylidene-D-ribonic acid-gamma-lactone;

b. adding an antisolvent into a solution containing 2, 3-O-isopropylidene-D-ribonic acid-gamma-lactone, cooling to a crystallization temperature, and precipitating a solid;

c. and screening out granular crystals from the solid.

Preferably, the temperature is reduced to the crystallization temperature before the temperature is reduced to the crystallization temperature to culture the crystal nucleus.

The crystallization temperature is the temperature when the solution begins to separate out crystal nucleus, and the crystal nucleus cultured for a period of time at the temperature is favorable for improving the purity and the yield of the subsequent cooling crystallization.

Preferably, the crude product containing 2, 3-O-isopropylidene-D-ribono-gamma-lactone is dissolved in an ester solvent at a temperature higher than 40 ℃ to obtain a solution containing 2, 3-O-isopropylidene-D-ribono-gamma-lactone. Preferably, the solvent temperature is above 40 ℃ and below the boiling point. Preferably below 80 deg.c. Preferably 75-80 ℃ ester solvent.

Preferably, the anti-solvent is added after completion of the nucleation culture.

Preferably, the anti-solvent is an alkane solvent.

Preferably, the ester solvent is one or more of ethyl acetate, propyl acetate and tert-butyl acetate, and ethyl acetate is preferred.

Preferably, the anti-solvent is an alkane solvent with less than 16 carbon atoms, preferably n-heptane, n-hexane, cyclohexane and petroleum ether, and more preferably n-hexane.

Preferably, the ratio of the volume (ml) of the ester solvent to the mass (g) of the crude product is greater than 1: 1 (ml: g); preferably greater than 1: 1 (ml: g), not higher than 4: 1 (ml: g).

Preferably, the ratio of the volume of the anti-solvent to the volume of the ester solvent is not higher than 1: 1; preferably, not higher than 1: 1, not less than 1: 3.

Preferably, the crystallization temperature is not higher than 25 ℃.

Preferably, the crystallization temperature is-5 to 25 ℃; preferably 5 ℃ below zero to 10 ℃; more preferably 0 deg.c.

Preferably, the crystallization time is not less than 1 h; preferably not less than 2 h; preferably not less than 3 h; preferably not less than 4 h.

Preferably, the seeding temperature is 30 ℃.

Has the advantages that:

1. the method is simple to operate and suitable for large-scale production;

2. the product obtained by the method has high purity and yield.

Drawings

FIG. 1 is a 2, 3-O-isopropylidene-D-ribono-gamma-lactone HNMR chart, 1H NMR (delta 500MHz, CDCl)₃)4.84(d,J＝5.6Hz,1H),4.79(d,J＝5.6Hz,1H),4.64(t,J＝1.9Hz,1H),4.00(dd,J＝12.2,2.3Hz,1H),3.82(dd,J＝12.2,1.7Hz,1H),2.41(s,1H),1.48(s,3H),1.39(s,3H)；

FIG. 2 is a chart of isomeric impurities HNMR, 1H NMR (. delta.500 MHz, CDCl₃)4.82(dd,J＝7.8,3.6Hz,1H),4.58(d,J＝7.8Hz,1H),4.45(d,J＝13.2Hz,1H),4.34(d,J＝3.6Hz,1H),4.20(dd,J＝13.1,1.6Hz,1H),3.26(s,1H),1.47(s,3H),1.37(s,3H)；

FIG. 3 shows the isomeric impurity m/z (H)⁺) FIG. (M/z 189.1[ M + H ]]⁺)；

FIG. 4 is a photograph of granular crystals obtained after recrystallization using the method of the present invention;

FIG. 5 is a photograph of powdered crystals obtained after recrystallization using the method of the present invention;

FIG. 6 is a TLC chart of examples 1 to 3, in which 1, 2 and 3 represent the recrystallized products of examples 1, 2 and 3, respectively, the upper trace in the chart represents the product 2, 3-O-isopropylidene-D-ribono-gamma-lactone, and the lower trace represents the impurity of the isomer;

FIG. 7 is a TLC chart of example 12, in which crude crystals, powdery crystals, and mother liquor represent granulated crystals after recrystallization, and the mother liquor represents a filtrate after precipitation of solids, and the upper trace in the chart represents the product 2, 3-O-isopropylidene-D-ribono-gamma-lactone, and the lower trace represents an impurity of an isomer;

FIG. 8 is a TLC chart of example 13, in which crude product, powder, and mother liquor represent crude product, powdery product after recrystallization, and filtrate after precipitation of solid is filtered, and upper marks in the chart represent the product 2, 3-O-isopropylidene-D-ribono-gamma-lactone, and lower marks represent impurities of isomers.

Detailed Description

The experimental procedures used in the following examples are all conventional procedures unless otherwise specified.

The materials, reagents and the like used in the following examples are all ordinary and commercially available products unless otherwise specified, and the reagents are commercially available, wherein the purity of the reagents is industrial grade.

The invention will now be further described by way of the following examples, which are not intended to limit the scope of the invention in any way. It will be understood by those skilled in the art that the equivalent substitutions and modifications made in the present disclosure are within the scope of the present invention.

The crude 2, 3-O-isopropylidene-D-ribono-gamma-lactone used in the following examples was obtained according to the literature "A convention, Efficient and Production-Scale Synthesis of a Protected l-lyoxolactone Derivative" and two substances were obtained by separating the crude product by high performance liquid chromatography, which were the target compound 2, 3-O-isopropylidene-D-ribono-gamma-lactone and impurities, respectively, and the nuclear magnetic spectra were the mass spectra of FIGS. 1 and 2 and 3, respectively. And judging the impurity to be an isomer of 2, 3-O-isopropylidene-D-ribonic acid-gamma-lactone by a nuclear magnetic map and a mass spectrogram.

Examples 1 to 5

Cooling the solution containing 75-80 deg.C ethyl acetate (crude product dissolved in ethyl acetate and formed into uniform solution) to the temperature for precipitating crystal nucleus (crystallization temperature), in this example 30 deg.C, after precipitating solid, slowly stirring at 80r/min for crystallization for 30min (crystallization aims at culturing crystal nucleus and improving purity and yield during subsequent crystallization), then naturally cooling the solution to crystallization temperature, changing the stirring speed to 200r/min, stirring for crystallization for 12h, and filtering to obtain the product.

The influence of the solvent and the crystallization temperature was varied in the above manner to examine the recrystallized product, and the results are shown in the following table.

The solids precipitated in the above examples were in the form of white, matt granules. Yield ═ yield/crude × 100%.

When 100mL of ethyl acetate is added to 100g of crude product, excessive solid is precipitated, and stirring is difficult, which is not favorable for production scale-up.

To know the purity of the product, the product was dissolved in ethyl acetate and judged by TLC (developing solvent ethyl acetate: n-hexane: 3:1, alkaline potassium permanganate solution color). This is because, on the one hand, neither the target product nor the impurities respond to ultraviolet light and cannot be purified by high performance liquid chromatography, and therefore, the purity of the product is judged by TLC chart. In examples 1 to 3, as shown in FIG. 6, as the concentration of the crude product in the ethyl acetate solution decreased, the color development of impurities (marks located at the lower side in the figure) became less noticeable on the TLC chart, and the product of example 3 developed a trace amount of impurities. The product of example 4 (not shown in FIG. 6) had a more pronounced impurity coloration and exhibited an effect similar to that of example 1.

Examples 6 to 12

Cooling a solution (100g of crude product dissolved in 300mL of ethyl acetate to form a uniform solution) containing 75-80 ℃ ethyl acetate to a temperature (crystallization temperature) at which crystal nuclei are precipitated, wherein the temperature is 30 ℃ in the embodiment, slowly stirring at a stirring speed of 80r/min for crystallization for 30min after solids are precipitated, then dropwise adding n-hexane, naturally cooling to the crystallization temperature after dropwise adding is completed, changing the stirring speed to 200r/min, stirring for crystallization for a period of time, and filtering to obtain a product.

In addition, the crystallization temperature, the addition volume of n-hexane and the crystallization time were changed by the above method, and the influence of the crystallization temperature on the recrystallized product was examined, and the results are shown in the following table.

Examples 6 to 12 precipitated solids that were granular crystals (refer to fig. 4) and powder crystals (refer to fig. 5), in which the granular crystals were the objective product and the powder crystals (non-objective product) were a mixture of the objective product and impurities. Yield ═ 100% granular crystals/crude.

Regarding the purity of the product, the granular crystals obtained in examples 6 to 12 had insignificant or trace impurity coloration, as judged by TLC after dissolving the granular crystals in ethyl acetate, and the impurity coloration became significantly lighter as compared with the crude product. Thus, the impurity content of the product after recrystallization is significantly reduced. As shown in fig. 7, which is a TLC chart of example 12, the target product ("crystal" shown in the figure) is substantially free of isomeric impurities.

In terms of yield, the yield after adding n-hexane is significantly higher than that without n-hexane in comparative examples 4 and 6 to 8. In comparative examples 6 to 8, the yield of crystalline particles increased with the increase of the amount of n-hexane, and reached an extreme value after 200ml, and the increase of the amount of n-hexane had no effect. Comparing examples 7, 9, 10, the yield can be improved by lowering the crystallization temperature, and when the temperature is lowered to 0 ℃, the extreme value is reached, and no obvious effect is achieved by continuously lowering the temperature. The crystallization time of the comparative examples 10 to 12 is prolonged, so that the yield can be increased, and after the crystallization time is prolonged to 4 hours, the yield reaches an extreme value, and no obvious effect is achieved after the crystallization time is continuously prolonged.

Example 13

Cooling a methyl tert-butyl ether solution (100g of crude product dissolved in 300ml of methyl tert-butyl ether to form a uniform solution) filled with 50-55 ℃ to a temperature (crystallization temperature) for precipitating crystal nuclei, in the embodiment, 20 ℃, slowly stirring at a stirring speed of 80r/min for crystallization for 30min after solid is precipitated, then dropwise adding 200ml of n-hexane, naturally cooling to 0 ℃ after dropwise adding, changing the stirring speed to 200r/min, and stirring for crystallization for 4h to obtain 56.4g of a white powdery product, wherein crystals with two different properties are not formed as in embodiments 6-12.

The TLC chart of the product is shown in fig. 8, and in comparison of the crude product (crude), the powdery product (powder) and the filtrate (mother liquor) after solid precipitation and filtration, the product has more obvious impurity coloration, and the impurity content is not significantly reduced compared with the crude product.