52 results about "Diisobutylaluminum hydride" patented technology

The present invention publicly discloses a synthetic method and intermediates of rosuvastatin calcium and synthetic methods of the intermediates. The synthetic method uses 4-4′-fluorophenyl-6-isopropyl-2-(N-methyl-N-methylsulfonylamino)pyridine-5-formaldehyde as the raw material, includes 4-4′-fluorophenyl-6-isopropyl-2-(N-methyl-N-methylsulfonylamino)pyridine-5-acrylonitrile (intermediate I) from a nitrilized reaction, and 4-4′-fluorophenyl-6-isopropyl-2-(N-methyl-N-methylsulfonylamino)pyridine-5-acraldehyde (intermediate II) from an aldehydized reaction of the intermediate I, and further goes through such unit processes as side-chain extension, ketone-group reduction, ethyl-group hydrolysis and neutralization reaction or decomposition reaction to obtain rosuvastatin calcium. The nitrilized reagent can be phosphate diethylacetonitrile, acetonitrile, etc.; the aldehyde reductant can be diisobutyl aluminum hydride, red aluminum, etc.; and the ketone-group reductant can be diethylmethoxyborane, NaBH4, KBH4, etc.

The invention discloses a catalyst charging method in neodymium polybutadiene rubber polymerization processes. The catalyst charging method comprises following steps: (1) ethylaluminum sesquichloride, diisobutylaluminum hydride, and neodymium neodecanoate are mixed according to a certain ratio so as to obtain a mixed catalyst, the mixed catalyst is delivered into a static mixer for ternary aging, wherein aging time ranges from 25 to 35min, and aging temperature ranges from 25 to 35 DEG C; (2) the mixed catalyst obtained via aging is delivered into a premixing kettle with a mixture of butadiene and a solvent oil for buffer treatment, and then an obtained mixed material is delivered into a polymerization kettle for polymerization, wherein pressure of the polymerization kettle ranges from 0.35 to 0.45 MPa, a first polymerization kettle temperature ranges from 60 to 75 DEG C; and (3) a part of diisobutylaluminum hydride is directly added through the middle-lower part of the premixing kettle into the polymerization kettle without aging, and is reacted with the mixed material obtained via step (2) for polymerization so as to prepare polybutadiene rubber. Beneficial effects of the catalyst charging method are that: reaction is stable; activity is stable; temperature is stable; the catalyst charging method is beneficial for Mooney viscosity control; and polybutadiene rubber product quality is stable.

The invention relates to a novel method of synthesizing tafluprost. The method comprises the following steps: after suitable protection by Corey Lactone, reducing by DIBAL (Diisobutylaluminium hydride); carrying out Wittig reaction, carboxyl protection and Swern oxidization to obtain a universal intermediate compound 1; and by taking the intermediate 1 as a raw material, carrying out reactions to obtain tafluprost (deprotection step is not taken into consideration, and fluorination is the last step) and a plurality of intermediate products. The intermediate 1 is connected with different omega chains to synthesize other various prost analogues such as misoprost, travoprost and latanoprost. 2-4 prost analogues can be further used for synthesizing other 16-phenoxyl prost.

The invention discloses a preparation method of mirabegron, which relates to the technical field of medicine preparation, comprising the following steps: R-mandelic acid and p-nitrophenylethylamine undergo amide condensation reaction at high temperature to obtain intermediate (R)- 2‑Hydroxy‑N‑(4‑nitrophenethyl)‑2‑phenylacetamide; then the amide carbonyl is reduced by diisobutylaluminum hydride to obtain the intermediate (R)‑2‑((4‑nitro Phenylethyl)amino)-1-phenylethanol hydrochloride; then the nitro group is reduced by the ammonium formate-Pd / C reduction system to obtain the intermediate (R)-2-((4-aminophenylethyl)amino) ‑1‑phenylethanol; final condensation reaction with aminothiazoleacetic acid to obtain mirabegron. The mirabegron prepared by the present invention has good purity, high yield, few synthetic circuit steps, mild and controllable conditions, simple and convenient operation, low cost and is suitable for industrial production, and has broad prospects and industrial application value.

The invention relates to a preparation method of a sunitinib intermediate 2, 4-dimethyl-5-formoxyl-1H-pyrrole-3-formyl (N, N-diethyl ethylenediamine). The method comprises the following steps: (1). carrying out a condensation reaction on ketene dimer and N, N-diethyl ethylenediamine to generate a compound II; (2). sequentially generating a nitrosation reaction and a reduction reaction on methyl acetoacetate to obtain a product, and reacting the product with the compound II obtained in the step (1) to generate a compound III; and (3). generating a reduction reaction on the compound III obtained in the step (2) in the presence of diisobutylaluminum hydride (DIBAL-H) to generate the sunitinib intermediate. Compared with an existing method, the method disclosed by the invention has the advantages of simplifying the reaction process, improving the yield of the intermediate and reducing the three-waste pollution, thereby having an important application value.

The invention relates to a sulfoacid rare earth catalyst for polymerizing high-cis-isoprene rubber and a preparation method thereof. The catalyst comprises benzenesulfonic acid neodymium rare earth complex and alkyl aluminum; the molar ratio of the alkyl aluminum to the rare earth neodymium in the benzenesulfonic acid neodymium rare earth complex is 15 to 40:1, wherein the benzenesulfonic acid neodymium rare earth complex comprises benzenesulfonic acid neodymium alcohol complex, benzenesulfonic acid neodymium sulphoxide complex, benzenesulfonic acid neodymium furan complex, benzenesulfonic acid neodymium amine complex, benzenesulfonic acid neodymium ether complex and benzenesulfonic acid neodymium ester complex; ligand comprises: alcohol compound, sulfoxide compound, furan compound, aminecompound, ether compound and ester compound; and the alkyl aluminum comprises: 3-isobutyl aluminum, triethyl aluminum, diisobutyl aluminum hydride, or diethyl aluminum hydride. The sulfoacid rare earth complex catalyst is used for polymerizing isoprene, and can obtain the high-cis rare earth polyisoprene rubber with the cis 1,4 structure content more than 96.0 percent and the weight-average molecular weight more than 2.2 million.

The invention discloses a synthesis method of cephanolide C. The method comprises the steps of taking commercially available 5-bromine-2-methylanisole as a synthesis raw material, performing Ei-ichi Negishi reaction, methoxy contraposition halogenation, and lithium diisopropylamide formylation reaction, allowing a product and 3-pentene-2-ketone to give Robinson cyclization reaction, performing Luche reduction, hydrolysis and esterification reaction to form a lactone compound, performing acid treatment after diisobutyl aluminum hydride reduction to form a Heck reaction precursor, performing palladium catalyzed carbonyl esterification coupling reaction, esterification and carbonyl reduction, then performing sequential oxidation, eemethylation and hydroxyl protection by trifluoromethylsulfonyl via 2,3-dichloro-5,6-dicyan para-quinone and pyridinium chlorochromate, and performing palladium catalyzed removal to achieve chemical synthesis of cephanolide C for the first time. The method has the advantages of concise and efficient synthesis route, easiness and simplicity in operation, low cost and the like, is applicable to massive synthesis of cephanolide C and provides an important material basis for bioactivity evaluation of a natural product, namely cephanolide C.

The invention relates to a method for preparing alpha-AlH3 by use of diisobutylaluminum hydride and LiBH4 as the catalyst, relates to a preparation method for alpha-AlH3, and aims to solve the problem that conditions required by direct synthesis of alpha-AlH3 through aluminum and hydrogen are strict. The method comprises the following steps: adding aluminum powder, diisobutylaluminum hydride and LiBH4 in an autoclave; introducing hydrogen, reacting at the condition with the temperature of 100-150 DEG C, and drying to obtain the product. In the method, the reaction pressure is 10-15 MPa which is much lower than 10 GPa, the reaction temperature is 100-150 DEG C which is much lower than 650 DEG C, through XRD tests, the synthesized product contains alpha-AlH3, and the method is applied to preparation of alpha-AlH3.

The invention discloses a method for synthesizing (S)-2-benzyloxypropanal, the steps comprising: first reacting (S)-2-benzyloxypropionic acid with ethylenediamine to obtain (S)-2-( 1‑benzyloxyethyl)‑4,5‑dihydro‑1H‑imidazole; (S)‑2‑(1‑benzyloxyethyl)‑4,5‑dihydro‑1H‑imidazole was dissolved in Water and ethanol, and then add sodium metal under the protection of nitrogen to stir the reaction; after the reaction, remove the ethanol, and slowly add the residue to the saturated oxalic acid solution under the protection of nitrogen, stir evenly and then reflux for reaction. After the reaction is completed, extract, dry, filter, and remove The product (S)‑2‑benzyloxy propanal is obtained after solvent. The present invention prepares (S)-2-benzyloxypropanal in two steps; the preparation process does not use diisobutylaluminum hydride which is expensive and easy to catch fire during post-treatment, thereby fully improving the operational safety and reducing the Production cost; the preparation process is mild and easy to operate, without the anhydrous conditions required by traditional process reactions, and it is easy to realize industrial production.

The invention discloses a synthesis method of a cephalotaxus sinensis terpenoid framework compound. The method comprises the following steps: commercially available 2-methyl-5-bromoanisole as a synthetic raw material is subjected to Ei-ichi Negishi reaction for para-halogenation with a methoxyl group, then a product is subjected to formylation reaction with lithium diisopropylamide, and a 1,3-dicarbonyl compound is obtained; the 1,3-dicarbonyl compound is subjected to a Robinson cyclization reaction with 3-pentene-2-one, and a lactone compound is obtained through Luche reduction, hydrolysis and esterification reaction; acid treatment is performed after reduction by diisobutylaluminum hydride, a Heck reaction precursor is obtained and subjected to palladium-catalyzed carbonyl esterificationcoupling reaction, and chemical synthesis of the crude cephalotaxus sinensis terpenoid framework compound is achieved by esterification. The synthetic route has the advantages of being simple, efficient, convenient to operate, low in cost and the like, and the method is applicable to large-scale synthesis of the cephalotaxus sinensis terpenoid framework compound, and provides an important experimental basis for chemical synthesis of cephalotaxus sinensis terpenoid natural products.

The invention relates to a preparation method of 2-((1S3aR7aR)-5-tert-butyloxycarbonyltetrahydrofuro[3,4]piperidine-1)acetic acid. The preparation method comprises 11 steps: carrying out esterification on a dicarboxylic acid piperidine compound 1 in thionyl chloride to obtain a diester compound 2; then reducing a pyridine ring by utilizing palladium carbon to obtain a compound 3; then taking the compound 3 to react with Boc acid anhydride to obtain a Boc protected compound 4; hydrolyzing the compound 4 by utilizing lithium hydroxide to obtain a dicarboxylic acid compound 5; carrying out ring closure in acetic anhydride to obtain a compound 6; carrying out reduction and ring opening by utilizing NaBH4 to obtain a mixture of position isomerism compounds 7A and 7B; carrying out the ring closure in the presence of iodomethane and potassium carbonate to generate position isomerism lactone 8A and 8B; step 8, reducing the 8A, obtained by column passing separation, by utilizing DIBAH (Diisobutylaluminum Hydride) to obtain a compound 9; carrying out Wittig reaction to obtain a compound 10; carrying out Michael addition under an alkaline condition to obtain a compound 11; finally, hydrolyzing the compound 11 under the alkaline condition to obtain a final compound.

The invention discloses a method for synthesizing natural product (+)-Strictifolione. The present invention utilizes 3-phenylpropanal and Evans chiral auxiliary agent to carry out aldol condensation reaction, then reduces with diisobutyl aluminum hydride, and then adds 3-propylene bromide activated by metal indium to obtain the compound of formula 5; enol Silicone ether reacts with acrolein under the action of titanium tetraisopropoxide and (R)-1,1-binaphthol, then reduces the carbonyl group with sodium borohydride, and then uses pyridinium p-toluenesulfonate for ring closure, and then forms a After the sulfonyl group becomes a leaving group, the acid is added to obtain the compound of formula 11; the compound of formula 5 and the compound of formula 11 are subjected to metal coupling reaction using Grubbs second-generation catalyst to obtain (+)-Strictifolione. The "dichotomy" synthesis method of the present invention is simple and reasonable in design, easy to operate, mild in reaction conditions, less in linear steps, high in product yield, and greatly reduces production cost.