208 results about "Pyridine hydrochloride" patented technology

The invention relates to a method for preparing clopidogrel. The conventional synthetic methods have the disadvantages of poor environmental protection, disadvantageous industrial production, low optical purity of final products and high cost. The technical scheme adopted by the invention comprises the following steps of: performing a reaction on a compound, namely, R,S-o-chloromandelic acid and methanol to produce R,S-chloromandelic acid methyl ester; performing the reaction on the R,S-chloromandelic acid methyl ester and benzene sulfonyl chloride under the action of an alkaline catalyst to produce 2-benzenesulfonic acyloxy-2(2-chlorphenyl) methyl acetate; performing an SN2 substitution reaction on the 2-benzenesulfonic acyloxy-2(2-chlorphenyl) methyl acetate and 4,5,6,7-tetrahydro-thiophene pyridine hydrochloride under an alkaline condition to produce R,S-clopidogrel free alkali; resolving the R,S-clopidogrel free alkali in resolving solvent by using a resolving agent; and dissociating the resolved R,S-clopidogrel free alkali to prepare the clopidogrel. In a synthetic route of the invention, reaction conditions are temperate, used reaction substrates are environmentally friendly, reaction yield in each step is high, the optical purity of a final product is up to over 99.5 percent, and pollution-free production can be realized.

The invention discloses a preparation and refinement method of esomeprazole magnesium. The preparation and refinement method comprises the following steps: condensing 2-chloromethyl-3, 5-dimethyl-4-methoxyl pyridine hydrochloride and 2-sulfydryl-5-methoxy-benzimidazole serving as starting materials, carrying out improved sharpless asymmetric oxidation so as to prepare esomeprazole sodium, then carrying out salt displacement so as to prepare esomeprazole magnesium, and finally refining to obtain high-purity esomeprazole magnesium. The preparation method is mild in reaction conditions, simple to operate, good in repeatability and high in yield and facilitates industrial production. The chromatographic purity of esomeprazole magnesium prepared by the method is above 99.8%; the optical purity of esomeprazole magnesium reaches above 99.6%; esomeprazole magnesium is stable in morphology and can meet medicinal requirements.

The invention discloses a new synthesis route of 5-(alpha-cyclopropyl carbonyl-2-fluorobenzyl)-2-oxo-2, 4, 5, 6, 7, 7a-hexahydrothiophene [3, 2-c] pyridine, which only needs to one step to convert prior 2-methoxy-5-(alpha-cyclopropyl carbonyl-2-fluorobenzyl)-4, 5, 6, 7-tetrahydrothiophene [3, 2-c] pyridine hydrochloride to target compound, with mild reaction conditions, non low temperature demand, non explosive material, high yield, low cost and high efficiency. The invention is suitable for large-scale industrial production.

The invention relates to the field of chemical engineering, particularly a method for recovering pyridine from a pyridine hydrochloride water solution, which comprises the following steps: by using dichloroethane as an extractant, carrying out extraction distillation twice, and rectifying to obtain the pyridine with higher recovery rate (up to 90-95%). The invention can reduce the waste of resources, and does not pollute the environment, thereby reducing the production cost and enhancing the economic benefit.

The invention provides a method for pure water phase preparation of rabeprazole sodium and belongs to the technical field of medicines. The method is characterized in that an intermediate, 2-hydroxymethyl-3-methyl-4-(3-methoxyl propoxy) pyridine hydrochloride, of the rabeprazole sodium is adopted as a raw material to be subjected to chlorination reaction, condensation reaction and oxidation reaction, so as to synthesize the rabeprazole sodium through three steps. The method adopts a novel chlorination reaction system and a novel sodium hypochlorite oxidation system, and can achieve a higher chloridization rate and excellently control a sulfur ether intermediate to be oxidized into sulfoxide; the reaction conditions are wild; both the reaction conversion rate and the reaction selectivity are very high; few reaction by-products are produced; the whole process can be carried out under the condition of no solvent; the content of residual solvent is lowered; time-consuming and toilsome vacuum rectification is not needed; the operation is simplified to a great extent; the process flow is short; and suitability for industrial application is achieved.

The invention provides a method for recovering pyridine from waste pyridine hydrochloride for producing chloromethyl isopropyl carbonate and cyclically reutilizing the pyridine. The method comprises the following process steps that: the pyridine hydrochloride and water are placed into a container according to a proportion being 1:2 to be stirred to obtain pyridine hydrochloride water solution, the pyridine hydrochloride water solution and two times of pyridine hydrochloride liquid caustic soda are placed into an enamel reaction kettle to be sufficiently stirred for taking reaction to generate pyridine and sodium chloride water solution, the pyridine and sodium chloride water solution are automatically produced in the still state, the upper layer is water-containing pyridine, the lower layer is sodium chloride water solution, the water-containing pyridine at the upper layer is taken out and is subjected to impurity removal through precipitation, rectification elution is adopted for removing water to obtain finished products, and the sodium chloride water solution is conveyed into a concentration pot to be concentrated to obtain sodium chloride finished products. The finished product pyridine can be used as one ingredient to be conveyed into a chloromethyl isopropyl carbonate production process line to be cyclically utilized for producing chloromethyl isopropyl carbonate. The method has the advantages that the resource waste is reduced, the environment cannot be polluted, meanwhile, the production cost of the chloromethyl isopropyl carbonate is also greatly reduced, and the economic benefits of enterprises are improved.

A deodorant is prepared by the following components by mass: 5-10 parts of potassium permanganate, 5-10 parts of NaClO, 15-20 parts of activated carbon powder, 5-10 parts of polyhydric alcohol, 3-8 parts of fungicide, 8-15 parts of nitrate, 5-8 parts of essences and 25-45 parts of water, wherein the polyhydric alcohol is one or several of propylene glycol, glycerol or ethylene glycol; and the nitrate is one or several of silver nitrate, zinc nitrate or copper nitrate. The deodorant is alkyl pyridine hydrochloride or n-octyl-isothiazolinone. The deodorant uses chemical deodorization, adsorption deodorization and covering deodorization in matching mode, is added with high-concentration bacteriacide, has efficient sterilizing and deodorizing effect and is particularly suitable for large treatment plants heavy in stink.

The invention relates to chemical synthesis for D-fluorescein. Wherein, using hot demethylate reaction to 2- cyano-6-methoxyl benzothiazole and pyridine hydrochloride with high purity to extract reaction production for column chromatography; finally, taking condensation reaction for demethylate production and D-cysteine to obtain objective product. This invention is simple, needs mild condition and easy to control. The product has yield more than 60% and purity more than 50%, and achieves level of Sigma L-9504 but with low price.

The invention discloses a novel synthesis process of prasugrel. The novel synthesis process comprises the steps: firstly, carrying out benzyl protection by taking 4, 5, 6, 7-tetrahydrothieno[3, 2-c]pyridine, benzaldehyde and sodium triacetoxyborohydride as starting raw materials to generate 5-benzyl-4, 5, 6, 7-tetrahydrothieno[3, 2-c]pyridine; then, brominating the 5-benzyl-4, 5, 6, 7-tetrahydrothieno[3, 2-c]pyridine by using hydrobromic acid to obtain 2-bromo-5-benzyl-4, 5, 6, 7-tetrahydrothieno[3, 2-c]pyridine; next, catalytically synthesizing 2-acetoxy-5-benzyl-4, 5, 6, 7-tetrahydrothieno[3, 2-c]pyridine by taking palladium acetate as a catalyst and XPhos as a ligand; and finally, carrying out hydrodebenzylation, and coupling the product with alpha-bromo-o-fluorobenzyl cyclopropyl ketone to obtain a target molecule 2-acetoxy-5-(alpha-cyclopropylcarbonyl-2-fluorobenzyl)-4, 5, 6, 7-tetrahydrothieno[3, 2-c]pyridine hydrochloride, i.e., the prasugrel hydrochloride. The process is simple, convenient and novel in route, easy to obtain raw materials, mild in condition, convenient to operate, high in total yield up to 80-90% and suitable for large-scale production.

The invention discloses a preparation method for canrenone. According to the preparation method, canrenone is obtained through an etherification reaction and a dehydrogenation reaction, wherein 17 beta-hydroxyl-4-alkene-3-ketone-17 alpha-pregnene-21-carboxylic acid-gamma-lactone is taken as a raw material; under the presence of a catalyst, the etherification reaction is carried out between 17 beta-hydroxyl-4-alkene-3-ketone-17 alpha-pregnene-21-carboxylic acid-gamma-lactone and triethyl orthoformate to generate 17 beta-hydroxyl-3,5-diene-3-ethoxy-17 alpha-pregnene-21-carboxylic acid-gamma-lactone; the catalyst is pyridine hydrobromide or pyridinium hydrochloride; under the presence of an organic solvent, the dehydrogenation reaction is carried out between an etherification reaction product and an oxidant to generate canrenone; the oxidant is tetrachloro-p-benzoquinone, tetrachloro-o-benzoquinone or 2,3-dichloro-5,6-dicyano-p-benzoquinone. Through the adoption of the preparation method, canrenone of which the purity is 99% or higher can be eventually obtained, and the total weight yield can reach 90% or higher. Therefore, the preparation method is suitable for industrialized production.

The invention discloses a method for preparing 2,3-dihydro-1H-pyrrolo-[3,4-c] pyridine hydrochloride. A target product is obtained through lactamization, reduction and salification by taking furo[3,4-c] pyridine-1,3-dione as an initial raw material, and the compound is an important medical intermediate.

The invention relates to a method for synthesizing a pregnenolol acetate and a congener thereof. In the method, a three-step reaction consisting of cracking, oxygen oxidation and rearrangement and elimination is undergone in a 'one-pot' based on steroid sapogenin to obtain the pregnenolol acetate and the congener thereof. By adopting the method, the problem of environmental pollution caused by the use of a metal compound and high-toxicity pyridine hydrochloride is solved in the reaction, and the problem of the harm of high-toxicity solvents, including acetonitrile, benzene and the like to operating personnel is eliminated. The method has the advantages of simple equipment, easiness and convenience for operation, mild condition and high total yield. A more environmentally-friendly and simpler method is provided for the industrial production of pregnenolone acetate.

The invention relates to the field of medicine production and in particular relates to a preparation method of a rabeprazole sodium crystal type compound. The preparation method of the rabeprazole sodium crystal type compound comprises the following steps of: by taking 2-mercapto benzimidazole and 2-chloromethyl-3-methyl-4-methoxy propoxy pyridine hydrochloride as raw materials and carrying out a condensation reaction to prepare rabeprazole thioether, and subsequently carrying out an oxidation reaction via the rabeprazole thioether and carrying out salt forming reaction via rabeprazole and sodium hydroxide to acquire the rabeprazole sodium. According to the preparation method of the rabeprazole sodium crystal type compound, the raw materials are low in cost and easy to purchase; samples are basically invariant in related substances and contents under the condition with high temperature and high humidity; the articles are stable in property and low in overall manufacturing cost; and the preparation method of the rabeprazole sodium crystal type compound has the advantages of strictly controlling the temperatures in the steps, being less in by-products, high in yield and non-toxic, and also has the advantages of being short in production period and further improving the production efficiency.

The invention discloses a cefalonium preparation method. The method is characterized by adopting 7-ICAC (1((7-amino-2-hydroxyl-8-oxo-5-thio-1-azabicyclo[4.2.0]octane-2-alkene-3-base)methyl)-4-carbamyl pyridine hydrochloride) and thiopheneacetyl chloride as raw materials, and reacting at the pH of 6-7 so as to obtain the product. The cefalonium provided by the invention is simple in preparation technology, simple to operate, high in yield, high in purity and suitable for industrial production and has a high application value.

The invention relates to a cation exchange membrane and a preparation method thereof. The cation exchange membrane is characterized in that the membrane has a semi-interpenetrating network structure and uses a microporous membrane as the support material, membrane pores are filled with functional polymer, and the functional polymer has a structure formed by the polymerization of allyloxy pyridinebenzene sulfonate or alkyl allyloxy pyridine benzene sulfonate. The preparation method includes the steps of firstly, performing monomer preparation, to be more specific, allowing sodium 4-hydroxybenzenesulfonate to have reaction with 3-halogenated propylene or 3-halogenated-2-alkyl propylene, and allowing the acquired product to have reaction with pyridine hydrochloride to obtain a monomer solution; secondly, forming the membrane, to be more specific, mixing the monomer solution with a crosslinking agent, an initiator and comonomer to form membrane making liquid, filling the membrane making liquid into the pores of the microporous membrane support material, and heating to perform polymerization reaction to obtain the cation exchange membrane. The cation exchange membrane is applicable toelectrodialysis.

The invention relates to a synthetic method of prasugrel. 2-bromo-1-cyclopropyl-2-(2-fluorophenyl) acetone and 4,5,6,7-tetrahydro thieno [3,2-C] pyridine hydrochloride are condensed under the action of alkali, so that an intermediate, namely 1-cyclopropyl-2-(6,7-dihydro thieno [3,2-C] pyridine-5(4H)-yl)-2-(2-fluorophenyl) acetone, is obtained, and then oxidation and acylation are carried out, so that prasugrel is obtained. The synthetic method of prasugrel has the advantages that a prasugrel intermediate is synthesized, condensation yield is high, operating steps are simple, protection and deprotection steps in the prior art are eliminated, and cost is greatly saved.