Method for preparing betulinic acid
FIELD: chemical technology, natural materials, medicine, pharmacy.
SUBSTANCE: invention relates to the improved method for preparing betulin from betulinic acid that can be used in preparing anti-tumor and anti-HIV medicinal preparations. Method for preparing betulinic acid involves oxidation of betulin with chrome (VI) oxide in acetic acid to betulonic acid and reduction with sodium boron hydride to betulinic acid. Betulonic acid sodium salt is reduced to betulinic acid and reduction reaction is carried out at room temperature at the concentration of sodium boron hydride 1.0-6.0 wt.-%. Invention provides simplifying method for preparing betulinic acid, reducing its cost and enhancing ecological safety of the process of it producing.
EFFECT: improved preparing method.
1 cl, 4 ex
The invention relates to methods of producing biologically active substances from the products of chemical processing of plant biomass, and in particular to methods of obtaining Betulinol acid from betulin-product of the processing of birch bark. Betulin acid (3β-hydroxy-20(29)-lupen-28-OIC) inhibits the growth of cancer cells, and has anti-HIV activity
Known platitudinal way to obtain Betulinol acid from betulin [US 5804575, 08.09.1998], which first made by the protection of the primary hydroxyl group in the form of tetrahydropyranol ether, then protection of the secondary hydroxyl group by acylation with acetic anhydride in pyridine, followed by removal of tetrahydropyranol protection. Next, carry out the oxidation of monoacetate betulin Jones reagent in monoacetate Betulinol acid with the subsequent receipt of Betulinol acid by removal of acetyl groups with potassium carbonate in methanol.
This method has a high stereoselectivity (obtained mainly 3β-hydroxy-20(29)lupen-28-OIC acid, which has in contrast to 3α-hydroxy-20(29)lupen-28-OIC acid biological activity), but it has several disadvantages. The disadvantages of this method are its multi-stage, and therefore, the length of the process, a small sum is ary yield of the target product (50-60%), as well as the use of toxic solvents and reagents.
Known multi-stage method of obtaining Betulinol acid [US 6271405, 07.08.2001], on which the company first acelerou acetic anhydride in the betulin diacetate, then treated with isopropylate aluminum with obtaining betulin-3-acetate. The primary hydroxyl group of betulin-3-acetate is oxidized to aldehyde dimethylsulfoxide and oxalylamino at -60°C. the resulting aldehyde oxidized to the acid by oxygen in the presence of cobalt (III) acetylacetonate in cryptomelane. The hydrolysis of ester bonds with sodium hydroxide in methanol results in Betulinol acid, the total yield which was 62-65%.
This method is complex, multistage, energy-intensive, as it requires the creation of low temperatures (-60°).
Known two-stage method of obtaining Betulinol acid [Kim Darrick S. H. L., Chen Zhidong, Nguen van Tuyen, Pezzuto, John M.// Synth Commun., 1997, V.27, N 9, R-1612], which betulin oxidized with Jones reagent in betulonovoi acid, and then restore the sodium borohydride in tetrahydrofuran for 12 hours at 0°C. the Decomposition of the excess sodium borohydride spend diluted hydrochloric acid. The allocation of Betulinol acid is carried out by distillation, 50% of tetrahydrofuran under vacuum, followed by dilution of the reaction mixture with ethyl acetate,washing the organic solution, distillation of the solvent under vacuum. Betulinol acid is obtained in the form of a mixture of 3αand 3β-hydroxy isomers in the ratio 1:19.
This method of ethnological due to the use of highly explosive tetrahydrofuran, and also because of the time consuming stage of recovery at 0°With (12 hours).
A method of obtaining Betulinol acid oxidation of betulin pyridinediamine complex with subsequent restoration received betulone acid in Betulinol with sodium borohydride in alcohol With2-C4[EN 2190622, 10.10.2002].
The disadvantage of this method is the use of explosive, toxic solvents (alcohols C2-C4).
The closest in technical essence and the achieved result is a method for the synthesis of Betulinol acid from betulin [Le Bang Sean A.P., Kaplun ALEXANDER Shpilevsky UA etc.// Bioorganic chemistry, 1998, 24, N10, S-793], consisting in the oxidation of betulin oxide chromium (VI) in acetic acid in betulonovoi acid. To clean betulone acid chromium compounds it is transformed into the sodium salt, which is separated, cleaned, and then again turn in betulonovoi acid. Betulonovoi acid restores Betulinol with sodium borohydride in methanol. The output of Betulinol acid used in this method was 53% at soothes the research Institute 3α -:3β-hydroxy isomers of 3:17.
The disadvantages of this method are its complexity and the lack of necessity to perform the operation of turning the sodium salt betulone acid in free betulonovoi acid and ecologicall due to the use of highly toxic methanol at the stage of recovery.
Object of the invention is the simplification of the method of obtaining Betulinol acid, its cheaper and safer process.
The problem is solved in that in the method of obtaining Betulinol acid, comprising the oxidation of betulin oxide chromium (VI) in acetic acid in betulonovoi acid and recovering the sodium borohydride in Betulinol acid according to the invention restores the sodium salt betulone acid in Betulinol acid, and restoration is carried out in water at room temperature when the concentration of the sodium borohydride from 1.0 to 6.0 wt.%.
Comparative analysis with the prototype shows that the distinctive features of the prototype feature is the recovery of the sodium salt betulone acid in Betulinol acid, bypassing the stage of transformation of the sodium salt betulone acid again in betulonovoi acid. This reduces operations such as treatment with hydrochloric acid, dissolved in ether, washing with water, drying with sodium sulfate, about the race broadcast. In addition, the distinctive features of the prototype feature is the recovery in water at room temperature (in the prototype, the recovery is carried out in methanol), which greatly simplifies and cheapens the process, making it more environmentally friendly and safe. Hallmark is also conducting recovery when the concentration of the sodium borohydride from 1.0 to 6.0 wt.%.
The process is as follows.
Betulin oxidized by the oxide of chromium (VI) in acetic acid for 10 minutes at a temperature of 15-20°C, the reaction mixture was diluted with 10% aqueous sodium chloride solution, extracted with diethyl ether, washed with ether extract 10% aqueous solution of sodium chloride. Received betulonovoi acid is converted into the sodium salt by the action of sodium hydroxide solution. The precipitated sodium salt betulone acid washed with diethyl ether and dried. The recovery process is as follows: dissolve in water sodium borohydride, add the sodium hydroxide to stabilize sodium borohydride [Achaios "Complex hydrides in organic chemistry". L.: Chemistry, 1971, p.61], in small portions with stirring sodium salt betulone acid. The recovery process was performed at room temperature for 4-10 hours. The excess sodium borohydride is decomposed with 10% hydrochloric acid the. Betulinol acid is extracted with ethyl acetate, the extract washed, dried over sodium sulfate and then the ethyl acetate is distilled off, the residue is recrystallized from methanol. After recrystallization get Betulinol acid in a mixture of 3βand 3α-isomers in the ratio of 4.6:1 (according to the PMR-spectroscopy).
The invention is confirmed by specific examples.
Example 1. In a flask with a volume of 500 ml is poured 150 ml of glacial acetic acid, add 3.75 g of betulin and to the resulting solution was added with stirring a solution of 3.75 g of chromium oxide (VI) 10.5 ml of 50% acetic acid. The oxidation is conducted for 10 minutes at a temperature of 18-20°C. Then the reaction mixture is poured 150 ml of 10% solution of sodium chloride. The reaction mixture was extracted with diethyl ether 2×150 ml. Ether extract is washed 4 times with 10% aqueous solution of sodium chloride, ether extract, then add 75 ml of 4 n sodium hydroxide solution, forming a white precipitate of sodium salt betulone acid. Sodium salt betulone acid is separated from the ether and water layers, washed with diethyl ether and dried. In a flask of 250 ml is poured 200 ml of water, add 2.5 g of sodium borohydride, 0.1 g of sodium hydroxide, then with stirring 4.0 g of sodium salt betulone acid. Stirring is continued the ri room temperature for ten hours. The excess sodium borohydride is decomposed, Prilepa 20 ml of 10% hydrochloric acid. Betulinol acid is extracted with ethyl acetate 3×100 ml), the ethyl acetate solution washed with 10% solution of sodium chloride, dried with sodium sulfate, the solvent is distilled off. After recrystallization from methanol receive Betulinol acid in a mixture of 3βand 3α-isomers in the ratio of 4.6:1 (according to the PMR-spectroscopy) with the release of 73.5 wt.% from the sodium salt betulone acid.
Example 2. Experience in conduct similar to the experience described in example 1, but at the stage of recovery of the sodium salt betulone acid sodium borohydride increase the concentration of sodium borohydride to 1.5 wt.%. To 100 ml of water is added 1.52 g of sodium borohydride, 0.05 g of sodium hydroxide and stirring enter 2,62 g of sodium salt betulone acid. Stirring is continued until completion of the reaction recovery within 9 hours. The output of Betulinol acid - 73,1 wt.% from the sodium salt betulone acid.
Example 3. Experience in conduct similar to the experience described in example 1, but when the concentration of the sodium borohydride to 4.4 wt.%. To 30 ml of water is added to 1.38 g of sodium borohydride and 0.003 g of sodium hydroxide, then with stirring of 2.38 g of sodium salt betulone acid. Stirring is continued for 6 hours. The output of Betulinol acid - 73,4 wt.% from the sodium salt of b is tulanboy acid.
Example 4. Experience in conduct similar to the experience described in example 1, but at the stage of recovery of the sodium salt betulone acid sodium borohydride concentration of sodium borohydride to 6.0%. To 30 ml added to 1.9 g of sodium borohydride and 0.003 g of sodium hydroxide, then with stirring enter of 2.38 g of sodium salt betulone acid. The recovery process lasts for 4 hours. The output of Betulinol acid - 73,6 wt.% from the sodium salt betulone acid.
With increasing concentration of sodium borohydride reduced during the process. Increasing the concentration of sodium borohydride above 6 wt.% by increasing its quantity at constant volume of water is impractical, as it would lead to unreasonably large molar ratio of sodium borohydride, sodium salt betulone acid (at a 6% concentration of sodium borohydride it is 10:1). Increasing the concentration of sodium borohydride by reducing the volume of water will increase the viscosity of the reaction mass. The decrease in the concentration of sodium borohydride is less than 1 wt.% will increase recovery time (more than 10 hours).
The results of the experiments confirmed the PMR and IR - spectroscopy: data PMR-spectroscopy: (CDCI3) (δ), (ppm) 4,79 (single. 1H, 29N); 4,65(single. 1H, 29N); 3,44(triple. 1H, 3H α-hydroxy-isomer) 3,22 (duplicates. the duplicates. 1H, 3H β-hydrox the-isomer); 3,02 (trips, N); 1,66 (single. 3H, 3 O-IU); 0,79; 0,83; 0,88; 1,0; 1,01 (all single. 5 metal bands 23-, 24-, 25-,26-, 27-IU); 1,05-2,24 (multiplet C-H). The ratio of integrated intensities at 3,44 and 3.22 to 1:4,6. The data of IR spectroscopy: (CVG), 3449, 2941, 2869, 1686, 1639, 1451,1376, 1235, 11186, 1043, 8886 (cm-1).
Thus, this invention provides a simpler, more environmentally friendly way of getting Betulinol acid due to the use as solvent of water instead of organic solvents in the recovery stage, as well as by reducing the operation of turning the sodium salt betulone acid in betulonovoi acid.
The method of obtaining Betulinol acid, comprising the oxidation of betulin oxide chromium (VI) in acetic acid in betulonovoi acid and recovering the sodium borohydride in Betulinol acid, characterized in that the restore sodium salt betulone acid in Betulinol acid, and restoration is carried out in water at room temperature and the concentration of sodium borohydride from 1.0 to 6.0 wt.%.
FIELD: organic chemistry, steroids, pharmacy.
SUBSTANCE: invention describes unsaturated 14,15-cyclopropanoandrostanes of the general formula (I):
wherein R1 means hydrogen atom (H), hydroxy-group (OH); R2 means hydroxy-group (OH), hydrogen atom (H); R3 means hydrogen atom (H), (C1-C10)-alkyl at α- or β-position; R4 means halogen atom (F, Cl, Br) or pseudohalogen group (azide, rhodanide), hydroxy-group (OH), perfluoroalkyl; R5 means (C1-C4)-alkyl; if double bond is at 1,2-position then R4 can mean hydrogen atom (H). Also, invention relates to a method for preparing these compounds and pharmaceutical compositions containing these compounds. Compounds of the formula (I) are compounds eliciting gestagenic and/or androgenic effect.
EFFECT: improved preparing method, valuable medicinal properties of compounds.
11 cl, 1 tbl, 9 ex
where R1- Oh, (H,H), (H,OR), NOR, where R is H1-6alkyl, C1-6acyl; R2- H or C1-6alkyl, R3- H, or R3- C1-6alkyl, C2-6alkenyl,2-6quinil, possibly substituted with halogen, R4- H, C1-6alkyl or C2-6alkenyl; R5- C1-6alkyl, R5- H, R7- H, C1-6alkyl, R8Is H, OH, halogen;
R9and R10independently H, or R9and R10independently C1-6alkyl, possibly substituted C1-4alkoxy or halogen;
R11- H, SO3H1-15acyl, dashed line indicates a possible link from4,5(10)or4,9-diene system
< / BR>whereis = O, -HE, or SIG or ООСR, where R represents an alkyl group having from 1 to 6 carbon atoms; R6represents H or -(CH2)mN, where m = 1 or 2; R7represents H, C1-4-alkyl, C2-4alkenyl or2-4-quinil; R11represents H, C1-4-alkyl, C2-4alkenyl,2-4-quinil; E represents, including the carbon atoms 16 and 17 of the D ring, a 4-7-membered hydrocarbon ring, where the specified ring is in the-position relative to the D-ring, substituted by a group REand optionally contains one endocyclic double bond; RErepresents H, C1-5-alkyl, C2-5alkenyl,2-5-quinil,1-5-alkyliden, -(CH2)n-N3or -(CH2)n-SP, where n = 1 or 2, and where the alkyl group may be substituted by-OR, -OOCR where R is alkyl with 1-6 carbon atoms; R17is-HE-or SIG or ООСR, where R is alkyl with 1-6 carbon atoms, where the aforementioned steroid compound may be, but neeba is either ring may be aromatic