Method for preparing 24-epibrassinolide

FIELD: organic chemistry of steroids, chemical technology.

SUBSTANCE: invention relates to the improved method for preparing chemical compounds of steroid order, namely, to a method for preparing epibrassinolide representing (22R,23R,24R)-2α,3α,22,23-tetrahydroxy-B-homo-7-oxa-5α-ergostane-6-one and relating to biologically active substance - a phytostimulator regulating growth of plants. Method involves the successive carrying out the following stages: a) synthesis of ergosterol mesylate by treatment of ergosterol with methanesulfochloride in pyridine; b) synthesis of isoergosterol by boiling ergosterol mesylate in aqueous acetone in the presence of potassium (sodium) hydrocarbonate; c) synthesis of isoergosterone by oxidation of isoergosterol with chrome anhydride in pyridine; d) synthesis of 7,8-dihydroergosterol by reduction of isoergosterone with sodium dithionite in the presence of a solubilizing medium containing cationic, anionic or nonionic surface-active substances of the following order: CnH2n+1X wherein n = 9-18; X means -NMe3, -NEt3, -COOH, -SO3H, -OSO2M, -OP(O)(OM)2 wherein M means alkaline metal, polyethylene glycol, (C2-C6)-aliphatic alcohols or monoesters of ethylene glycol or diethylene glycol as a co-solubilizing agent, electrolyte and water taken in the molar ratio = 1:(5-6):(100-250), respectively; e) steroid rearrangement of 7,8-dihydroisoergosterol; f) formation of 24-epicastasterone by treatment of (22E,24R)-5α-ergosta-2,22-diene-6-one with methanesulfoneamide and potassium carbonate with using catalytic amounts of potassium ferricyanide (III) and osmium tetraoxide; g) dissolving 24-epicastasterone formed in chloroform followed by treatment with trifluoroperacetic acid forming in mixing trifluoroacetic anhydride and hydrogen peroxide in chlorinated organic solvent, and isolation of the end product of the formula (I) with high yield.

EFFECT: improved preparing method.

2 cl, 7 ex

 

The invention relates to the production of chemical compounds belonging to the class of steroid compounds, specifically to an improved method for producing a 24-epibrassinolide (2α, 3α, 22R, 23R, 24R)-2,3,22,23-tetrahydroxy-B-Homo-7-oxa-5α-cholestan-6-it, which is the biologically active substance, phytostimulation regulating plant growth, inhibition transpiration and wilting, and also a means of reinforcing cold resistance, accelerating growth, thickening or ripening fruits, roots and tubers, stems or follicles, increasing the fertility of bees, fish, meet the General formula (I):

A known method of producing steroid isoelectron formula

Isoelectric (3α, 5-cyclo-24R-methyl-5α-cholesta-7,22-Dien-6β-ol) is produced by interaction of ergosterol with sulphonylchloride - methanesulfonamido in pyridine (turn in mesilate) and boiling received alfaprostol in aqueous acetone in the presence of potassium bicarbonate. Reach the target product yield 94%. This compound is an intermediate product in the synthesis of natural phytohormone - 24-epibrassinolide (EN 2024541).

A method of obtaining another steroid 3α, 5-cyclo-24S-ethyl-5α-cholesterol-22-EN-6-she (sorgoleone) formula

The method includes processing the source stigmasteryl para-toluenesulfonyl chloride, the processing of the received tosilata of stigmasteryl base, oxidation of 3,5α-cyclo-24S-ethyl-5α-cholesterol-22-EN-6-it chromic acid and isolation of the target product, and as the Foundation of the use of potassium acetate, and the oxidation carried out directly in the reaction mixture (SU 1162816, 23.06.1985, CL 07 J 9/00). The overall yield of 80%. This compound is an intermediate product when receiving hormone brassinolide) and its synthetic analogue of (22S, 23S, 24S)-homobrassinolide, is highly active as plant growth stimulators.

A method of obtaining brassinosteroid derivatives of formula (II) and (III).

The compound of formula (II) are known invention (hereinafter referred to as compound (II)and the compound of formula (III) (hereinafter referred to as compound (III)) can be formed with a large output through dihydroxyl derivatives having a hydroxy-group in the 2α-position and 3α-position, by adjusting the number of the reaction agent, in the exercise of catalytic hydroxylation connection 24S-ethyl-5α-cholesta-2,22E-Dien-6-she, referred to as compound (IV) (Cmog, Agric. Biol. Chem., 44 (50, 1211, 1980) using katal is the critical number of camerahouse osmium, in the presence of tert-butylhydroperoxide or N-methylmorpholine N-oxide in an inert gas, such as nitrogen or argon. Thus obtained 2α and 3α-dihydroxytoluene (V) is dissolved in pyridine containing 4-dimethylaminopyridine for the reaction with propionic anhydride or butyric acid anhydride, and thus receive (VI) in the case of propionic anhydride or (VII) in the case of butyric acid anhydride. This compound (VI) or (VII) is dissolved in a chlorinated organic solvent, which is resistant to oxidation, and oxidized organic peroxide, such as adventurou acid, m-monochlorobenzene acid, m-monobromoacetic acid, monongalia acid, cryptanalyses acid and their sodium or calcium salt so that from compound (VI) is obtained the compound (II) or compound (VII) to the compound (III).

These compounds are used as active ingredients. A method of obtaining the active steroid 2α, 3α, 22S, 23S-tetraoxa-24S-atichrist-4-EN-6-she of the formula (VIII).

As a result of oxidation of CYCLOBUTANE (DC) chetyrehokisi osmium get diol (X), which is treated with bromine. The resulting dibromide (XI) dihydrobromide boiling in DMF in the presence of CT is onata lithium. Oxidize the formed Trianon (XII) in terms of the method of Woodward. At the final stage is conducted mild alkaline hydrolysis and receive 2α, 3α, 22S, 23S-tetraoxa-24S-atilhan-4-EN-6-he (VIII) (SU 1433005 A1, 30.12.1991).

A method of obtaining brassinolide) of the formula (XIV) by the interaction of 1 mole of the steroid of formula (XV), (where R1and R2Is h, alkyl or acyl group, R5and R6- H, alkyl, cycloalkyl or substituted phenyl with 1 to 5 moles cryptocercus acid in an inert solvent at a temperature(-20)-(+50)°C. Steroid of the formula (XV) is obtained by interaction of the steroid of formula (XVI), where R1and R2Is h, alkyl or acyl group; R3and R4- carbonyl or ketal) with the compound of the formula (XVII), (JP, 62167797, 24.07.1987, 07 J 3/00).

The technical objective of the claimed invention to provide a 24-epibrassinolide higher quality, i.e. getting more pure product (higher melting point), which leads to increased biological activity.

The goal of the project is achieved in a novel way of obtaining epibrassinolide formula (I),

includes the following stages: a) synthesis of nelfinavir ergosterol (XVIII) the processing of natural Sterol is ergosterol by methanesulfonamido in pyridine at a temperature of the reaction medium is not more than 12°C;

b) synthesis of isoelectron (XIX) obtained by boiling alfaprostol - nelfinavir ergosterol in aqueous acetone in the presence of potassium bicarbonate (buffer means);

C) synthesis of sorgoleone (XX) oxidation isoelectron with chromic anhydride in pyridine;

g) synthesis of 7,8-dihydroergosterol (XXI) the restoration of Aenon (ketone) isoelectron dithionite sodium in water microheterogeneous environment with high solubilities ability in the presence of solubilizers environment, including odnozadachnaya cationic, anionic or nonionic surfactants (surface-active substances) from a number WithnH2n+1X, where n=9-18, X=NMe3NEt3, COOH, SO3H, OSO2M, OP(O)(OM)2where M=metal, polyethylene glycol, coolability - aliphatic alcohols With2-C6or monetary ethylene or diethylene glycol, electrolyte and water at a molar ratio of their respective 1:5-6:100-250;

d) steroid rearrangement 7,8-dehydroisoandrosterone by heating it in a mixture of anhydrous lithium bromide, pyridinium hydrochloride and dimethylacetamide;

e) synthesis of epicastasterone (XXII) processing (22E,24R)-5α-ergosta-2,2-Dien-6-she methanesulfonamido and potassium carbonate using catalytic amounts of hexacyanoferrate (III) potassium and camerahouse osmium;

g) dissolving the formed thus tetrahydrozoline in chloroform followed by treatment triperoxonane anhydride in a chlorinated organic solvent with subsequent oxidation by hydrogen peroxide and the selection of the target product (I).

As the surfactant in the proposed method is used, for example, the following cationic, anionic or non-ionic surfactants from a number CnH2n+1X, where n=9-18, X=NMe3NEt3, COOH, SO3H, OSO2M, OP(O)(O)2where M = alkali metal.

Example 1. Receiving nelfinavir ergosterol.

In a two-neck flask of 250 ml, equipped with addition funnel, thermometer and stirrer, was prepared a solution of 10 g of ergosterol in 150 ml of pyridine (distilled over sodium hydroxide). The solution was cooled to 10°and with stirring dropwise added to 9.4 ml methanesulfonamide with such speed that the temperature of the reaction mixture did not rise above 12°C. the Mixture was stirred for 1 hour at 8-10°C, then poured it in 800 ml of water. The resulting suspension allowed to settle for about one hour, then the precipitate was filtered on a Buechner funnel. The precipitate was washed in 1000 ml of water, dried over sodium hydroxide in a desiccator for 12 hours. Received 11 g (92%) of product as a white powder that was used without further purification.

Example 2. Getting itarget is Rina.

In a two-neck flask of 2000 ml equipped with a reflux condenser and a stirrer, were mixed 1280 ml of acetone (distilled over KMnO4, 320 ml of water, and 1.15 g knso3. The resulting solution was heated to boiling, then under vigorous stirring quickly fell asleep in the flask 5.5 g finely ground nelfinavir ergosterol. The reaction mixture is boiled for 5 minutes, then was replaced by a reflux to the down and drove 500 ml of solvent. The flask was cooled first to room temperature and then to 0°C. Dropped out after a few hours, a white flocculent precipitate was filtered on a Buechner funnel and washed with 500 ml water, then dried in a desiccator over NaOH for 12 hours. After drying, the product was recrystallize from 150 ml of acetone, slowly (over 1 hour) cooling the solution from room temperature to -20°C. the Precipitated crystals were filtered on a Buechner funnel and dried in vacuum. Obtained 3.7 g (80%) of product as colorless needle-like crystals with TPL-131°C. PMR-spectrum (CDCl3, 500 MHz): 0,48 (2N), OF 0.66 (3H), 0,85 (6N), OF 0.90 (3H), OF 1.03 (3H), 1,10 (3H), 1,2-2,2 (unresolved complex multiplet), 3,4 (1H), AND 5.2 (2H), AND 5.5 (1H).

Example 3. Getting isoelectron

In a two-neck flask of 500 ml equipped with a dropping funnel and a stirrer, placed 70 ml of pyridine (PE is Eganova over NaOH). The flask was cooled to 15°and with stirring, added to 1.15 g of chromic anhydride. The mixture was stirred for 10 minutes to dissolve the chromium trioxide. For 50 minutes under vigorous stirring was added in 5 portions CrO3according to 1.15 g, keeping the temperature at 15-20°C. Received a suspension of complex CrO3with pyridine in pyridine. To the suspension was added via a dropping funnel a solution of 6.96 g of isoelectron in 70 ml of pyridine. The reaction mixture was stirred 24 h at 20°C. thereafter, the mixture was diluted with 300 ml diethyl ether, the precipitated residue was filtered on a Buechner funnel, washed with 100 ml of ether. The filtrate was evaporated in vacuum to dryness, the solid residue was recrystallize from 10 ml of acetone, got 4,63 g of the product as a pale yellow plate crystals with TPL-170°C. the mother liquor was evaporated and the obtained residue was chromatographically on a column of silica gel, using as eluent a mixture of petroleum ether and ethyl acetate in a ratio of 10:1. So got 0.84 g of product with TPL-169°C. the Total yield vs. 5.47 g (79%). PMR-spectrum (CDCl3, 500 MHz): 0,65 (3H), OF 0.77 (1H), 0,84 (6N), OF 0.93 (3H), OF 1.05 (3H), 1,2-2,3 (unresolved complex multiplet), and 5.2 (2H), AND 5.8 (1H).

Example 4. Getting 7,8-dehydroisoandrosterone.

The reaction is conducted in aqueous microheterogeneous environment with high solubilize the overall capacity (hereinafter referred to solubility environment). For such environments, a mixture of surface-active solubilizer, coolability, water and electrolyte in a ratio to achieve the optimal hydrophilic-lipophilic balance system. The resulting environment is thermodynamically stable, have visual homogeneity (transparent and not stratified by arbitrarily long ageing in the temperature range from room temperature up to 100° (C)capable of solubilizing without external signs of the formation of a new phase of a significant number of hydrophobic water-insoluble organic compounds (e.g., hydrocarbons, steroids) to molar concentrations. As a solubilizer used single-chain cationic, anionic or non-ionic surfactants from a number CnH2n+1X, where n=9-18; X=NMe3NEt3The SOOMA, SO3M, OSO2M, OP(O)(O)2The PEG.

As coolability used aliphatic alcohols normal or branched chain structure with a number of carbon atoms from 2 to 6, and monetary mono - or diethylene glycol.

The composition solubilizes environment - solubilizer-coolability-water in a molar ratio of 1:5-6:100-250. The components are mixed until a homogeneous solution, to be used further as a reaction medium. In a two-neck flask of 250 ml, equipped with a stir bar and reflux is holodilniki, put 65 ml solubility environment (as an example, the environment is prepared from 3,6 ml of n-butanol, 3.6 g of cetyltrimethylammonium bromide and 60 ml of water. The mixture was stirred at 20°until then, until it formed a clear solution (about 10 min). To the obtained solution under stirring was added a solution of 1.16 g of Aenon in 6 ml of toluene and 2.1 g of sodium bicarbonate. After the resulting mixture was passed under intensive stirring, a stream of nitrogen or argon for 10 min, after which the mixture was heated to boiling and added 1.2 g of dithionite sodium. Boil 1.5 h, when during this time another 2 servings of dithionite sodium 250 mg then cooled to 20°C, diluted methylene chloride (100 ml) and poured into 300 ml of saturated NaCl solution. Separated the organic layer, washed with water, (2×200 ml), saturated NaCl (1×200 ml) and dried over Na2SO4. The solution was evaporated in vacuum, the solid residue was dissolved in 50 ml of diethyl ether and pass through a short column (5 cm) with silica gel, the solution was evaporated in vacuum. The residue was chromatographically on silica gel (cyclohexane/ethyl acetate 80/1). Got 0,93 g (80%) of product as a white powder with TPL-111°C. PMR-spectrum (CDCl3, 500 MHz): 0,70 (3H), 0,81 (6N), TO 0.92 (3H), 1,02 (6N), 1,1-2,1 (unresolved complex multiplet), and 5.2 (2H).

Example 5. Receiving (22E, 24R)-5α-ergosta-2,22-Dien-6-it.

In a two-neck flask of 50 ml equipped with a reflux condenser, mixed 1 g of dehydroisoandrosterone, 0.11 g of anhydrous lithium bromide, 0.06 g of pyridinium hydrochloride, 10 ml of dimethylacetamide. Into the flask was allowed a stream of nitrogen, after which it was heated to 160°and withstood 3 h at this t-re. The mixture was cooled to 20°and poured it in 200 ml of water. The precipitate was filtered on a Buechner funnel and dried in a desiccator over NaOH. The obtained solid substance was recrystallize from 30 ml of methanol, got 0,82 g of the product as a white powder with TPL-4° (yield 82%). PMR-spectrum (CDCl3, 500 MHz): to 0.67 (3H), 0,70 (3H), 0,82 (6N), OF 0.91 (3H), OF 1.02 (3H), 1,2-2,4 (unresolved complex multiplet), and 5.2 (2H), the ceiling of 5.60 (1H), of 5.68 (1H).

Example 6. Obtaining 24-epicastasterone.

In a flask of 100 ml equipped with a stirrer, mixed 3 g of ergosta-2,22-Dien-6-she 1,497 g hexacyanoferrate(III) potassium, 0,629 g of potassium carbonate, 0,144 g methanesulfonamide, to 0.011 g of potassium osmate, 0,071 g of 4-chlorobenzoate of dihydroquinidine, 15 ml of tert-butanol and 15 ml of water. The mixture was stirred at 20°C for 6 days, after which was added 0.6 g of sodium sulfite and stirred for another 18 hours. Tert-butanol was distilled in vacuum, the residue was extracted with ethyl acetate (6×20 ml). The residue was washed 1 time with water (20 ml), 0.25 M sulfuric acid (3×20 ml), saturated NaCl (1×20 ml). The ethyl acetate was evaporated and the obtained OST is OK was chromatographically on silica gel, using as eluent a mixture of chloroform and ethyl acetate (9:1). The fractions containing epicastasterone has evaporated, got to 0.23 g of the product as a white powder with TPL-248° (Exit 77%). PMR-spectrum (CDCl3, 500 MHz): to 0.67 (3H), OF 0.77 (3H), 0,86 (6N), OF 0.93 (3H), AND 1.0 (3H), 1,1-2,2 (unresolved complex multiplet in), 2.25 (2H), 2,66 (1H), 3,41 (1H), AND 3.7 (1H), AND 3.8 (1H), 4,1 (1H).

Example 7. Getting epibrassinolide

In a two-neck flask of 50 ml equipped with a dropping funnel, stirrer, potassium chloride tube, mixed with 3.4 ml of chloroform, and 2.6 ml triperoxonane anhydride and 0,415 ml of 30% R-RA hydrogen peroxide. The resulting solution was cooled to 0°and dropwise with stirring was added a solution of 0.17 g of epicastasterone in 10 ml of chloroform. The mixture was stirred 2 h at 20°C, then diluted to 7 ml of chloroform. The resulting mixture was washed with water (1×10 ml), aqueous sodium carbonate solution (2×10 ml), hydrogen sulfite solution of sodium (2×10 ml), saturated NaCl solution and then dried over sodium sulfate. The solvent was evaporated in vacuum and the residue was recrystallize from 20 ml of ethyl acetate, having obtained 0.14 g of epibrassinolide in the form of a white powder with TPL-258°C. Obtained 0.14 g (80% of theory) of the PMR-spectrum (CDCl3, 500 MHz): 0,70 (3H), 0,85 (6N), 0,92 (6N), OF 1.05 (3H), 1,2-2,3 (unresolved complex multiplet), 3,10 (1H), 3,45 (1H), 3,7 (2H), 4,01 (1H)AND 4.2 (1H).

The advantages of the claimed method are:

a) the use of a wide range of cheap simple interchangeable surfactants, including those produced by domestic industry instead of unique import interfacial carrier, do not have available analogues;

b) solubility environment phase is thermodynamically stable liquid, whereupon the reaction mixture does not require special modes high-performance mixing (special stirrer speed control and so on). Can be used conventional stirrer (magnetic or mechanical), and the results of the process are practically independent of mixing conditions;

C) the results of the reaction are reproducible with respect to the main parameters of the process specified in the method;

g) the process does not depend on ineffective interfacial transfer of reductant anion, which allows the use of smaller amounts of dithionite sodium;

d) isolation of the product is carried out using standard procedures of extraction and does not require the use of large quantities of expensive chromatographic silica gel;

e) the product of higher quality (higher TPL), because it contains no impurities interfacial vector.

A method of obtaining a 24-epibrassinolide (22R,23R,24R)-2α,3α,22,23-tetrahydroxy-B-Homo-7-oxa-5α-ergosta-6-it General formula (I)

includes the following stages:

a) synthesis of nelfinavir ergosterol processing natural Sterol is ergosterol by methanesulfonamido in pyridine at a temperature of the reaction medium is not more than 12°C;

b) synthesis of isoelectron boiling received nelfinavir ergosterol in aqueous acetone in the presence of potassium bicarbonate (sodium) as buffer funds;

C) synthesis of isoelectron oxidation isoelectron with chromic anhydride in pyridine;

g) synthesis of 7,8-dihydroergosterol recovery isoelectron dithionite sodium in water microheterogeneous environment with high solubilities ability in the presence of solubilizers environment, including odnozadachnaya cationic, anionic or nonionic surfactants (surface active agents) of the number of CnH2n+1X, where n=9-18, X=NMe3NEt3, COOH, SO3H, OSO2M, OP(O)(O)2where M = alkali metal, polyethylene glycol, co-solubilizer - aliphatic alcohols C2-C6or monetary ethylene or diethylene glycol, electrolyte and water at a molar ratio of their respective 1:5-6:100-250;

d) steroid rearrangement, 7,8-dehydroisoandrosterone by heating it in a mixture of anhydrous lithium bromide, pyridinium hydrochloride and dimethylacetamide;

e) synthesis of 24-epicastasterone, processing(22E,24R)-5α -ergosta-2,22-Dien-6-she methanesulfonamido and potassium carbonate using catalytic amounts of camerahouse osmium and stoichiometric recyclates of hexacyanoferrate (III) potassium in the presence of a salt of the optically active amine 4-chlorobenzoate of dihydropyridine;

g) dissolving formed in this way 24-epicastasterone in chloroform followed by treatment cryptanalyses acid obtained by mixing triperoxonane anhydride and hydrogen peroxide in a chlorinated organic solvent, followed by separation of the target product (I).



 

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