CN108752361A - A kind of preparation method of hydroxycamptothecin - Google Patents

Abstract

The invention belongs to synthetic drug technical fields, more particularly to a kind of preparation method of hydroxycamptothecin, sour solvent dissolves camptothecine and oxidant sodium perborate is added, and is concentrated under reduced pressure reaction solution after isothermal reaction, be added ice water after crystal is precipitated completely, be filtered, washed, dry to obtain 1- oxygen camptothecines；1- oxygen camptothecines are added dioxane, acetonitrile, water and concentrated sulfuric acid dissolution and stir, with ultraviolet lamp and high pressure mercury, ice water condensation reflux；Be concentrated under reduced pressure, be added ice water after crystal is precipitated completely, be filtered, washed, dry to obtain crude product；Purifying crude.Easy to operate, safety economy of the invention, environmentally protective, gross production rate is high.

Description

A kind of preparation method of hydroxycamptothecin

technical field

The invention belongs to the technical field of synthetic medicines, and in particular relates to a preparation method of hydroxycamptothecin.

Background technique

10-Hydroxycamptothecin (HCPT) is a ten-hydroxylated derivative of camptothecin isolated from the fruit and leaves of Camptotheca acuminata (Camptotheca acuminata). It is an important intermediate of camptothecin anticancer drugs, so finding and developing the preparation method of HCPT is one of the important directions of research and development of camptothecin anticancer drugs. At present, there are four methods for preparing HCPT: direct extraction method, biotransformation method, chemical total synthesis method, and chemical semi-synthesis method. In 2017, Cen Ye et al. used ultrasonic-microwave co-extraction of HCPT in magma fruit, with an average extraction rate of 4.61%. This method consumes a large amount of solvent, the extraction process is complicated, and the yield is low. A large amount of extraction of HCPT will cause damage to the camphor tree resources. In 2014, Wang Lei et al. used camptophytic endophytic fungi to convert camptothecin to HCPT, and the conversion rate was 7.37%. However, the requirements for strain cultivation and screening techniques were high, the concentration of the product in the fermentation broth was low, the separation and extraction steps were cumbersome, and the amount of extraction solvent was large. The technology is still immature. In 2008, Liu et al successfully prepared HCPT through a series of reactions including Michael addition, intramolecular aldol condensation, oxidative aromatication, intramolecular Diels-Alder cycloaddition and Sharpless asymmetric dihydroxylation, with a yield of 14 %, but due to many reaction steps, low synthesis yield, large amount of organic solvents, serious environmental pollution, and the final product must be separated into D/L isomers, it cannot be mass-produced at present.

The content of camptothecin in natural camptothecin plants is about 10 times that of HCPT. In addition, the extraction process of camptothecin is relatively mature and the cost is relatively low. Therefore, it is economical and reasonable to use camptothecin as a raw material to prepare HCPT semi-synthetically. There are mainly two existing chemical semi-synthetic methods. The first is the quinoline ring reduction method: firstly use precious metals to catalytically hydrogenate camptothecin, and after reducing it to 1,2,6,7-tetrahydrocamptothecin, Then oxidize it to prepare HCPT; the second is the quinoline epoxidation method: first oxidize camptothecin to 1-oxycamptothecin with an oxidant, and then irradiate with a high-pressure mercury lamp to generate HCPT by photochemical rearrangement. The cost of precious metal catalysts used in the quinoline ring reduction method is high, the safety factor of the hydrogenation reaction is low, and the reaction conditions are not easy to control. The quinoline epoxidation method has certain advantages over the quinoline ring reduction method, but the operation is complicated and time-consuming.

Contents of the invention

The purpose of the present invention is to improve the quinoline epoxidation method of chemical semi-synthesis of hydroxycamptothecin, solve the problems of time-consuming, low safety factor, and inconvenient reaction operation in the prior art, and establish a convenient, efficient, and environmentally friendly new method.

A preparation method for hydroxycamptothecin, comprising the following steps:

(1) N-oxidation reaction

Heating the camptothecin in a water bath, at 30-45°C, add an acid solvent, stir and dissolve the camptothecin; raise the temperature to 60-70°C at a constant speed, add the oxidant sodium perborate, continue to stir and condense and reflux; continue the reaction, and wait until the reaction is over, Stop heating and cool down to room temperature naturally;

Concentrate the reaction solution under reduced pressure, add ice water to the concentrated solution, and let it stand for crystallization; after the crystals are completely precipitated, filter, wash with distilled water, and dry to obtain 1-oxocamptothecin;

Wherein the acid solvent is glacial acetic acid, formic acid, preferably glacial acetic acid; the ratio of camptothecin quality to glacial acetic acid volume is 1:50-1:200, preferably 1:100; the ratio of the amount of camptothecin to sodium perborate 1:10-1:70, preferably 1:45; the reaction temperature is 70-120°C, preferably 90°C; the reaction time is 30-100min, preferably 50min.

(2) Actinic rearrangement

Add dioxane, acetonitrile, water and concentrated sulfuric acid to the 1-oxocamptothecin prepared in the above steps to dissolve and stir, illuminate with ultraviolet high-pressure mercury lamp, and condense and reflux with ice water;

After the reaction is completed, stop the light, and cool naturally to room temperature; concentrate under reduced pressure, add a large amount of ice water to the reaction solution, and let it stand for crystallization; after the crystals are completely precipitated, filter, wash with distilled water, and dry to obtain crude HCPT;

Wherein the volume ratio of dioxane, acetonitrile and water is 5:3:1, water is distilled water, the volume ratio of concentrated sulfuric acid and distilled water is 1:70-1:120, preferably 1:100, 1-oxocamptothecin The ratio to the quality of distilled water is 1:50-1:150, preferably 1:100, the power of the ultraviolet high-pressure mercury lamp is 400-700W, preferably 500W, and the illumination time is 40-80min, preferably 60min. Reaction equation:

(3) crude product purification

Atmospheric pressure glass chromatography column, filled with silica gel. The height of the chromatographic column is 150-200mm, the diameter of the chromatographic column is 250mm, and the mass ratio of sample to silica gel is 1:50-1:100, preferably 1:100. Use chloroform to wet-pack the column, then dissolve the crude HCPT product prepared in the above steps with ethanol, and add a small amount of silica gel for dry loading. The volume ratio of methanol: chloroform is 1:30-1:70, preferably 1:49 as the flow equality elution, use test tubes to collect and number, TLC to monitor the product purity, after detection, merge similar fractions, and the HCPT content exceeds 98.5 % of the combined solution, the product was obtained after vacuum distillation and vacuum drying; the combined solution lower than this content was concentrated under reduced pressure until a solid was precipitated, and the concentrated solution was placed in the refrigerator to stand overnight, filtered, and the solid was vacuum-dried After obtaining more than 98.5% pure product, the total yield is 86.42%.

Technical effect of the present invention:

(1) The present invention uses sodium perborate as an oxidizing agent to prepare 1-oxocamptothecin, which shortens the oxidation reaction time and improves the oxidation reaction yield.

(2) The present invention uses a mixed solvent of 1,4,-dioxane, acetonitrile, and water with a volume ratio of 5:3:1 as the photochemical solvent, which improves the conversion rate of the photochemical reaction.

(3) The experimental operation of the present invention is simple, safe and economical, environmentally friendly, and the total yield is high, reaching 86.42%.

Description of drawings

Fig. 1 is the product 1-oxycamptothecin mass spectrogram of embodiment;

Fig. 2 is the ¹ H-NMR of the product 10-hydroxycamptothecin of embodiment;

Fig. 3 is the ¹³ C-NMR of the product 10-hydroxycamptothecin in the example.

Detailed ways

The specific technical solutions of the present invention are described in conjunction with the examples.

The preparation method of hydroxycamptothecin comprises the following steps:

(1) N-oxidation reaction

Accurately weigh an appropriate amount of camptothecin and place it in a round bottom flask. Heating in a water bath, at 30-45°C, add an acid solvent, stir for 10 minutes, and dissolve camptothecin. Raise the temperature to 60-70°C at a constant speed, add the oxidizing agent sodium perborate, continue to stir and condense to reflux. The temperature rises and the reaction continues. After the reaction was completed, the heating was stopped and cooled to room temperature naturally. The reaction liquid was concentrated under reduced pressure, a large amount of ice water was added to the concentrated liquid, and the crystallization occurred upon standing. After the crystals are completely precipitated, filter, wash with a small amount of distilled water, and dry to obtain 1-oxocamptothecin with a yield of 96.46%.

Wherein the acid solvent is glacial acetic acid; the ratio of the mass of camptothecin to the volume of glacial acetic acid is 1:100; the ratio of the amount of substances of camptothecin to sodium perborate is 1:45; the reaction temperature is 90°C; the reaction time is 50min .

(2) Actinic rearrangement

Put the 1-oxocamptothecin prepared in the above steps into a 1000mL photochemical reaction bottle, then add dioxane, acetonitrile, water and concentrated sulfuric acid to dissolve and stir, illuminate with ultraviolet high-pressure mercury lamp, and condense and reflux with ice water. After the reaction was completed, the light was stopped and cooled to room temperature naturally. Concentrate under reduced pressure, add a large amount of ice water to the reaction liquid, and let it stand for crystallization. After the crystals are completely precipitated, filter, wash with a small amount of distilled water, and dry to obtain crude HCPT. The volume ratio of dioxane, acetonitrile and water is 5:3:1, the volume ratio of concentrated sulfuric acid to distilled water is 1:100, the ratio of 1-oxocamptothecin to distilled water is 1:100, and the ultraviolet high pressure mercury The lamp power is 500W, and the illumination time is 60min.

(3) Column chromatography purification

Atmospheric pressure glass chromatography column, filled with silica gel. The height of the chromatographic column is 150-200mm, the diameter of the chromatographic column is 250mm, and the mass ratio of sample to silica gel is 1:100. Use chloroform to wet-pack the column, then dissolve the crude HCPT product prepared in the above steps with ethanol, and add a small amount of silica gel for dry loading. Methanol: trichloromethane volume ratio is 1:49 as mobile equivalence elution, use test tubes to collect and number, TLC to monitor product purity, after detection, combine similar fractions, and the combined solution with HCPT content exceeding 98.5% is distilled under reduced pressure , to obtain the product after vacuum drying; the combined solution lower than this content is concentrated under reduced pressure until just solids are precipitated, the concentrated solution is placed in the refrigerator to stand overnight, filtered, and the solids are vacuum-dried to obtain more than 98.5% pure product, The total yield is 86.42%.

Identification of the products obtained above:

(1) N-oxidation reaction product:

1-Oxycamptothecin is a yellow solid, identified by liquid chromatography-mass spectrometry, as shown in Figure 1. Chromatographic conditions: Agilent 1290 HPLC column (ACQUITY UPLC BEH C ₁₈ , 2.1×100mm, 1.7μm) separation, column temperature 30°C, flow rate 0.3mL/min; injection volume 0.1μl; mobile phase composition A: water + 0.1% formic acid, B: acetonitrile; Gradient elution program: 1-18min, 5-50%(B), 18-25min, 50-80%(B), 25-28min, 80-98%(B), 28 -33 min, 98-98% (B). The detection wavelength is 373nm. 1-Oxycamptothecin was identified using Waters Xevo G2-XS QTOF, ESI positive ion mode, and the mass scanning range was m/z:50-1000. HRMS m/z 365.1814 [M+H] ⁺ (calcd for C ₂₀ H ₁₆ N ₂ O ₅ , 364.3510).

(2) Photorearrangement reaction products:

10-Hydroxycamptothecin, pale yellow solid, mp: 264.4-265.6°C. The H NMR spectrum is shown in Figure 2, and the C NMR spectrum is shown in Figure 3; 240(15272),250(10706),255(15008),260(16376),267(24885),273(21642),281(4977),286(5957),292(5478),297(5635), 316(7999),332(10171),370(20037),385(23260);IR(KBr):3520,3095,2897,1722,1653,1594,1553,1505,1336,1262,1173,1049,836,746,669 cm ^-1 ; ¹ H-NMR (400MHz, DMSO-d ₆ ): δ0.88(t, J＝8Hz, 3H), 1.85-1.88(t, 2H), 5.23(s, 2H), 5.41(s, 2H), 6.48(s, 1H), 7.26(s, 1H), 7.28(d, J=4Hz, 1H), 7.41-7.44(dd, J ₁ =4Hz, J ₂ =8Hz, 1H), 8.03(d , J＝8Hz, 1H), 8.45(s, 1H), 10.32(s, 1H); ¹³ C-NMR (400MHz, DMSO-d ₆ ): δ8.20, 30.68, 50.56, 65.67, 72.83, 96.26, 109.23 ,118.56,123.46,129.71,130.10,130.35,131.08,143.65,146.34,149.85,150.48,157.09,157.28,172.94; HRMS m/ _z365.1814 [M+H] ⁺ ( _calcd for C ₂₂ H ₅₆ N ,364.3510).

Claims (7)

1. a kind of preparation method of hydroxycamptothecin, which is characterized in that include the following steps：

(1) N- oxidation reactions

Sour solvent, stirring and dissolving camptothecine is added at 30-45 DEG C in camptothecine heating water bath；It is at the uniform velocity warming up to 60-70 DEG C, is added Enter oxidant sodium perborate, continues stirring and condensing reflux；Sustained response stops heating, naturally cools to room to the end of reaction Temperature；

Reaction solution is concentrated under reduced pressure, ice water is added into concentrate, stands still for crystals；After crystal is precipitated completely, filtering, distillation washing It washs, it is dry to get 1- oxygen camptothecines；

(2) photochemical rearrangement

Dioxane, acetonitrile, water and concentrated sulfuric acid dissolution is added in 1- oxygen camptothecine made from above-mentioned steps and is stirred, with ultraviolet height Pressure mercury lamp illumination, ice water condensation reflux；

To the end of reaction, stop illumination, cooled to room temperature；It is concentrated under reduced pressure, a large amount of ice water is added into reaction solution, stand knot It is brilliant；After crystal is precipitated completely, water washing is distilled in filtering, dry to get HCPT crude products；

(3) purifying crude

Purifying crude is obtained into sterling with column chromatography methods.

2. a kind of preparation method of hydroxycamptothecin according to claim 1, which is characterized in that the acid described in step (1) Solvent is glacial acetic acid, formic acid.

3. a kind of preparation method of hydroxycamptothecin according to claim 1, which is characterized in that in step (1), camptothecine The ratio between quality and sour solvent volume are 1:50-1:200；The ratio between amount of substance of camptothecine and sodium perborate is 1:10-1:70.

4. a kind of preparation method of hydroxycamptothecin according to claim 1, which is characterized in that described in step (1) Sustained response, reaction temperature are 70-120 DEG C, reaction time 30-100min.

5. a kind of preparation method of hydroxycamptothecin according to claim 1, which is characterized in that , bis- Evil in step (2) The ratio between volume of alkane, acetonitrile and water is 5:3:1, the ratio between the concentrated sulfuric acid and water volume are 1:70-1:120,1- oxygen camptothecines and water quality The ratio between amount is 1:50-1:150.

6. a kind of preparation method of hydroxycamptothecin according to claim 1, which is characterized in that in step (2), ultraviolet height Pressure mercury lamp power is 400-700W, light application time 40-80min.

7. a kind of preparation method of hydroxycamptothecin according to claim 1, which is characterized in that the column described in step (3) Chromatogram purification includes the following steps：Normal pressure glass chromatography column, with silicone filler；Using chloroform wet method dress post, second is then used Alcohol dissolves HCPT crude products, admixes silica gel dry method loading, methanol：Chloroform volume ratio is 1:30-1:70, as mobile phase Isocratic elution is collected and is numbered using test tube, and TLC monitors product purity, and similar fraction is merged after detection, HCPT contents are surpassed The amalgamation liquid for crossing 98.5% obtains product after being evaporated under reduced pressure, being dried in vacuo；The amalgamation liquid of the content be will be less than through being concentrated under reduced pressure To there is solid precipitation, concentrate is put into refrigerator and is stood overnight, filtering, solid is dried in vacuo after obtain 98.5% or more it is pure Product.