The method of obtaining e-5-bromopentane-2
(57) Abstract:Usage: as synthons in the synthesis of biologically active compounds, prostaglandins, vitamins, pheromones, juvenile hormones. The inventive two-stage processing of the source cyclopropylethanol: first tribromide phosphorus in an inert absolute solvent in the presence of anhydrous lithium salts and organic bases, for example pyridine, at a temperature of minus 10 - 60oWith, then the selected 1-bromo-1-cyclopropylethyl treated with anhydrous zinc bromide in an inert absolute solvent, for example diethyl ether, tetrahydrofuran, at a temperature of minus 10 - 50oC. Receive 5-bromo-penten-2E (TRANS)-configuration 96%, Regio - and stereochemical purity with a yield not less than 80 %. 4 C. p. F.-ly. The invention relates to a stereo - and regioselective methods of synthesis of the E(TRANS)-gomoallilnymi bromides synthons of biologically active compounds, prostaglandins, vitamins, pheromones, juvenile hormones, etc. namely, the method of production of E-5-bromopentane-2.A method of obtaining E-5-bromopentane-2, based on the reaction of disclosure cyclopropanol ring source is th way to obtain E-5 bromantane-2 is low Regio - and stereoselectivity of this reaction, resulting mixture of several compounds. So in reaction to the disclosure cyclopropanol ring source cyclopropylethanol 47% Hydrobromic acid in accordance with the decision of the prototype is formed a mixture of four compounds:
+CH-(CH2)2Br+CH3- E-5-bromantan-2 (I), Z is 5-bromantan-2 (II) 1-bromo-1-cyclopropylethyl (III) and 1-bromo-2-methylcyclobutane (IV).Isolation and purification of the target product E-5-bromopentane-2 in this case is extremely difficult and practically does not provide the required purity of the product due to the close physical constants resulting from the reaction of the compounds, while the synthesis of biologically active compounds imposes high requirements as to isomeric and stereochemical purity of the individual components, because even a small admixture (1%) gomoallilnymi bromide Z-configuration does not allow to use it in stereo and regionalplanning the synthesis of natural biologically active substances.The problem to which the invention is directed, is to develop a Regio - and stereoselective method for the synthesis of E-5-bromo-pentene-2 a high degree of Regio - and stereochemie tasks developed the method of obtaining E-5-bromopentane-2 by processing cyclopropylethanol bromodomain reagent, followed by separation of the reaction products, in which, according to the invention, the first source cyclopropylethanol process tribromide phosphorus in an inert absolute solvent in the presence of anhydrous lithium salts and organic base at a temperature of minus (10-60)aboutWith, followed by separation of the resulting 1-bromo-1-cyclopropylethanol, which is then treated with anhydrous zinc bromide in an inert absolute solvent at a temperature of minus (10-50)aboutC. it is reasonable as an absolute solvent to use ethers, mainly, diethyl ether or tetrahydrofuran.It is also advisable to use as an organic base pyridine.By this way we obtain a final product of high degree of Regio - and stereochemical purity, suitable for further synthesis of biologically active compounds.Similarly can be obtained and E-5-Harpenden-2 when used as halogenous agent in the first stage, phosphorus trichloride and the second anhydrous zinc chloride under the same process conditions as in the case of receiving E-5-bromopentane-2.The essence of the invention, making the th, in two stages.In the first stage under the influence of haloesters agent, which is selected trichromacy phosphorus, in the presence of anhydrous lithium salts in an inert absolute solvent (diethyl ether, tetrahydrofuran, and others ) in the presence of organic bases, mainly, pyridine, at a temperature of minus (10-60)aboutWith the substitution occurs hydroxyl group source cyclopropylethanol on bromine
CH3- CH3- (2)
After separation of the resulting 1-bromo-1-cyclopropylamino conventional methods carry out the second stage of actually getting 5-bromopentane-2 E(TRANS) configuration by disclosure cyclopropanol ring under the action of anhydrous zinc bromide in an inert absolute solvent at a temperature of minus (10-50)aboutWITH:
CH3- CH3- -(CH2)2-Br (3)
The use of anhydrous zinc bromide as reagent that will reveal cyclopropanol ring and formation of a double bond, allows you to receive E-5-bromantan-2 a high degree of Regio - and stereochemical purity.After separation by conventional methods is the end product of E-5-bromantan-2 obtained with the yield of 80% identification methods Pamvotida example implementation of the method.P R I m e p. E-5-bromopentane-2 is carried out in two stages: "a" and "b".a) Obtaining 1-bromo-1-cyclopropylamine.To a mixture of 4.1 g (0.05 mol) of cyclopropylethanol, 3 ml (0,037 mol) in abs. pyridine, 8,3 g (0.09 mol) of anhydrous lithium bromide in 80 ml of abs. diethyl ether at a temperature of minus 30aboutWith added dropwise 3 ml (0.03 mol) trichromate phosphorus.The reaction mixture is stirred at a temperature of minus 30aboutC for 1 h and poured into ice water.The organic layer was separated, washed with water, sodium hydrogen carbonate solution, sodium chloride solution, then dried with magnesium sulfate. The ether is distilled off and the residue is distilled in vacuum.The result: 4.5 g (62%) of 1-bromo-1-cyclopropylamino with the following physico-chemical characteristics: boiling point: 55-58aboutC/75 mm RT. Art. According to the analysis of gas-liquid chromatography (GLC) the purity of the obtained product 97% RangeIH-NMR (CCl4, , M. D.): 0,3-1,3, m, 5H (cyclo3H5-); 1,5, g, 3H, J 6 Hz (CH3-); 3,2, m, 1H, J16 Hz, J28 Hz (-CH(Br)-).b) Receiving E-5-bromopentane-2 (final product).To a mixture of 4 g (0.018 mol) of anhydrous zinc bromide in 10 ml of the of Propylamine in 5 ml of abs.the ether. The mixture was stirred at 0aboutWith within days, poured into ice water, the organic layer was separated, washed with water, sodium chloride solution, dried with magnesium sulfate. The ether is distilled off, the residue is distilled in vacuum.The result obtained 3.7 g (80%) E-5-bromopentane-2, the boiling temperature of 68-70aboutC/100 mm RT. senior purity according to GC is not lower than 96% of RangeIH-NMR (CDCl3, , M. D.): 1,61 m, 3H (CH3CH=) 2,47 m, 2H, (-CH2CH=); 3,30 m, 2H, (CH2Br); 5,34, m, 1H (= ) 5,49, m, 1H (=CH-CH2-); J (SN=SN)of 13.9 Hz.From the presented data it follows that the resulting product has a high Regio - and stereochemical purity constant spin-spin interaction J is 13.9 Hz, which clearly indicates the TRANS configuration of double bonds.The applicant did not know the ways to obtain E-5-bromopentane-2, characterized by the set of essential features that are identical to the essential features of the claimed invention. 1. The METHOD of OBTAINING E-5-BROMOPENTANE-2 by processing cyclopropylethanol brainwashin agent, characterized in that as brainwashes agent use trichromacy phosphorus and the process is conducted in an inert absolute solvent in prisutstvie 1-bromo-1-cyclopropylethyl, which is then treated with anhydrous zinc bromide in an inert absolute solvent at a temperature of minus (10 - 50)oC.2. The method according to p. 1, characterized in that as an absolute solvent used simple aliphatic ether.3. The method according to PP.1 and 2, characterized in that as the inert solvent used diethyl ether.4. The method according to PP.1 and 2, characterized in that as the inert solvent used tetrahydrofuran.5. The method according to PP.1 to 4, characterized in that the organic base is used mainly pyridine.
FIELD: organic synthesis catalysts.
SUBSTANCE: catalyst is prepared from allyl chloride production wastes comprising 30-50% 1,3-dichloropropenes, 30-60% 1,2-dichloropropane, and 3-5% 1,2,3-trichloropropane, which are treated at 5-10°C with 30-50% dimethylamine aqueous solution in such amount as to ensure stoichiometric ratio of dimethylamine with respect to 1,3-dichloropropenes. Resulting mixture is held at 20-25°C for 0.5-1.0 h and then 40-44 sodium hydroxide solution is added in stoichiometric amount regarding dimethylamine, after which clarified waste is added to dimethylamine at 60-70°C and stirring in amount ensuring stoichiometric ratio of dimethylamine to 1,3-dichloropropenes contained in clarified waste. Mixture is aged for 2-3 h, organic phase is separated, and remaining interaction phase is supplemented by C1-C4-alcohol or benzyl alcohol at alcohol-to-dimethylamine molar ratio 1:(1-3).
EFFECT: reduced expenses on starting materials.
2 cl, 3 ex
FIELD: chlororganic chemistry.
SUBSTANCE: invention relates to hydrochlorination catalyst containing aluminum η-oxide, doped with cesium chloride. Also method for methanol hydrochlorination in vapor phase using claimed catalyst is disclosed.
EFFECT: decreased selectivity to dimethyl ether and inhibited coke deposition on working catalyst.
16 cl, 6 tbl, 1 dwg, 20 ex
FIELD: industrial organic synthesis.
SUBSTANCE: process involves interaction of carbon tetrachloride with methanol in gas phase at elevated temperature in fixed-bed reactor accommodating two heterogeneous contact beds with different active ingredient concentrations, said active ingredient being zinc chloride deposited on solid carrier. Process can be carried out in presence of hydrogen chloride and/or water additives.
EFFECT: increased specific output of the process and lifetime of catalyst.
1 dwg, 3 tbl, 7 ex
SUBSTANCE: catalyst contains zinc chloride and carrier - porous granulated carbon-carbonic composition material based on pyrocarbon and nanodispersed carbon with specific surface by "БЭТ" 350-650 m2/g and total pore volume by water 0.55-0.85 cm3/g. Described is method of preparation of catalyst described above, which is prepared by impregnating carrier with water or hydrochloric acid solution of zinc chloride in two stages: zinc chloride sorption by carrier from water solution at temperature 15-25°C and evaporation of remaining part of solution at temperature 80-100°C. Also described is process on obtaining methylchloride by catalytic hydrochlorating of methanol, which is carried out in continuous reactor at temperature 140-200°C and contact time 0.6-1.11 s in presence of described above catalyst.
EFFECT: complete methanol conversion and complete selectivity to methylchloride.
7 cl, 6 ex, 4 dwg
SUBSTANCE: invention relates to a method of converting organochloride wastes containing tetrachloromethane to methyl chloride by reacting organochloride wastes with methanol at high temperature in a gas phase in a cascade consisting of at least two series-connected reactors, by periodically redistributing the stream of the initial mixture to the cascade reactors. All reactors have at least two heterogeneous contact layers with different concentration of the active ingredient which is zinc chloride deposited on a solid support. The process is preferably carried out in the presence of hydrogen chloride additive and/or water.
EFFECT: longer service life of catalyst.
2 cl, 2 dwg, 1 tbl, 5 ex
SUBSTANCE: methyl chloride synthesis method involves reacting methanol with hydrogen chloride in a synthesis reactor to obtain a vapour-gas mixture containing methyl chloride, and extraction of methyl chloride from vapour-gas mixture via partial condensation, followed by washing with initial methanol which is then fed into the synthesis reactor, and distillation purification where methyl chloride is extracted in form of a distillate. The initial methanol is fed into the system in three streams, wherein a stream A is fed for washing, stream B is fed for distillation purification and the remaining stream C is fed directly into the synthesis reactor. The ratio of stream A to the overall stream (A+B+C) of the initial methanol is between 0.1 and 0.5; the ratio of stream B is between 0.3 and 0.7; the ratio of stream C is between 0.05 and 0.5.
EFFECT: highly efficient process owing to avoiding recycling the desired product into the synthesis reactor.
5 cl, 1 dwg, 2 ex
SUBSTANCE: invention relates to a method of producing methyl chloride, which involves reacting methanol with hydrogen chloride in a synthesis reactor to obtain a vapour-gas mixture and partial condensation thereof, where methyl chloride is removed from the system in vapour form. The condensate is fed into a fractionation column using calcium chloride as an agent which decomposes the hydrochloric acid azeotrope. The still liquor from the column is fed for evaporation of water, which is removed from the process, and the evaporated still liquor is returned into the column at the feed level, wherein the vapour-gas stream collected from the top of the column is returned into the synthesis reactor, and the still liquor is partially removed from the system while simultaneously feeding fresh aqueous calcium chloride solution into the system. The method is characterised by that the still liquor is neutralised with an aqueous suspension of calcium hydroxide before evaporation to pH 6.5-8, and then clarified.
EFFECT: method which enables production with more complete recycling of hydrogen chloride and also enables to recycle chloride and salt wastes from other processes of an organosilicon complex, while preventing loss of hydrogen chloride and formation of waste water.
6 cl, 4 ex, 1 dwg
SUBSTANCE: invention relates to a method of producing perfluoroalkyl bromide from triphenylphosphine dibromide, obtained by reacting triphenylphosphine with bromine in acetonitrile at 0 °C, and 1,1,3-H-perfluoroheptanol at temperature of 170–180 °C for 90 minutes.
EFFECT: easy implementation, replacing original toxic raw material, while maintaining high output of end product.
1 cl, 1 tbl, 3 ex
SUBSTANCE: invention relates to organic chemistry, in particular, to a method of producing bromocyclohexane, widely used in chemical and pharmaceutical industry. Method comprises producing bromocyclohexane by reacting cyclohexanol with a bromating agent while heating. Brominating agent used is (45–48)% hydrobromic acid in presence of benzene with volume ratio of acid to benzene 1:0.75 and molar ratio acid to cyclohexanol 3.5:1, reaction mass is held for 4 hours with simultaneous distillation of benzene-water azeotrope at a temperature of 70–72 °C and returning benzene to reaction medium, and bromocyclohexane is separated from benzene fraction by distillation.
EFFECT: implementation of method ensures high output bromocyclohexane in bromation of cyclohexanol, reduces amount of wastes, as well as setting up recycling during synthesis of bromocyclohexane.
1 cl, 2 dwg, 1 ex
SUBSTANCE: invention relates to method of obtaining 1,1-difluoro-2-bromoethylene through dehydrohalogenation of 1,1-difluoro-1,2-dibromoethane with an aqueous 15-30% solution of potassium hydroxide, which is added while stirring with simultaneous distillation of the formed 1,1-difluoro-2-bromoethylene in fractionation mode.
EFFECT: increased output of desired product from 83,2 to 96,3-98,5%.
1 cl, 3 ex