117 results about "Thioacetic acid" patented technology

The invention discloses an etidronic acid with the content of arsenic less than or equal to 3ppm and a process for preparing the same. The method is to use phosphorus trichloride, acetic acid and ammonium thioacetamide as raw materials and comprises the following steps of: putting one-third of the acetic acid and the ammonium thioacetamide into a reaction kettle, stirring to control the temperature and the pressure, slowly dropping one-third of the phosphorus trichloride and putting one-third of the ammonium thioacetamide into the reaction kettle, stopping stirring and keeping stand; controlling the temperature and the pressure; dropping the remaining phosphorus trichloride into the reaction kettle; then stirring for 1 hour with the rotational speed of 50 to 60 revolutions per minute, raising the temperature slowly and reflowing; controlling the temperature and the pressure while reflowing; hydrolyzing the esters produced after reflowing under the negative pressure; concentrating the materials, filling air, removing impurities, reducing the temperature, putting the remaining phosphorus trichloride into the reaction kettle, sealing the reaction kettle and keeping stand, and then putting the materials into a mixing tank; regulating and filtering the materials so as to obtain an HEDP product. The product has extremely little arsenic with less than or equal to 3ppm, which not only reduces the environmental pollution, but also expands the application fields.

The invention belongs to the field of pharmacy and relates to an optically pure thioacetic compound and application thereof to medicine. The optically pure thioacetic compound comprises levorotatory 2-(5-bromo-4-(4-cyclopropyl-naphthalene-1-base)-4H-1,2,4-triazole-3-based sulfenyl) acetic acid and dextral 2-(5-bromo-4-(4-cyclopropyl-naphthalene-1-base)-4H-1,2,4-triazole-3-based sulfenyl) acetic acid.

The invention relates to a preparation method of cefdinir. According to the invention, under the effect of triethylamine, 7-amino-3-vinyl-8-oxo-5-thia-1-azabicyclo[4.2.0]octa-2-alkene-2carboxylic acid is subject to a reaction with (Z)-2-(2-aminothiazole-4-group)-2-acetyl oxyimino thioacetic acid(S-2-benzothiazole), such that a cefdinir ester liquid is obtained; the cefdinir ester liquid is extracted; an organic solvent is added to the cefdinir ester liquid; acetyl is removed by alkaline hydrolysis; sylvite of a weak acid is added to the liquid, the pH value is controlled, such that cefdinir sylvite is obtained; the sylvite is dissolved by using water; an organic solvent is added to the solution; the pH value is regulated, such that cefdinir is obtained. With the method, yield and quality are substantially improved; crystal form of the product is stable; and the method is suitable for industrialized productions.

The invention discloses a novel fried wheat essence, comprising 2-acetylthiophene, furanone, 2,3-pentanedione, 3-methyl-2-cyclohexenyl-1-one, 2,3,5,6-tetramethylpyrazine, 5-methyl-6,7-dihydrocyclopentylpyrazine, 2-acetylpyrazine, tricin, furfuryl thioacetate, biradical disulfide and propylene glycol. The invention not only has fried wheat fragrance and but also can be used in the coarse grain beverage after baking, in particular to wheat smell milk beverage. Meanwhile, the invention can better enhance the mouthfeel and cover the bilgy odour and musty taste of legume coarse grain in base materials.

The invention relates to a preparation method of racecadotril. The method comprises the following steps: (1) enabling thioacetic acid to react with 2-benzylacrylic acid to prepare an intermediate 3-acetyl mercapto-2-benzyl propanoic acid; (2) carrying out amidation on the intermediate 3-acetyl thiol-2-glycin benzyl propionic acid and glycine benzyl ester p-toluenesulfonate salt under existence of a catalyst to generate the racecadotril. By adopting the method, the racecadotril with high yield and purity can be obtained, the defect of the original technology is compensated, pollution is reduced, and the cost is reduced. Thioacetic acid is used as a solvent and is also used as a reaction reagent, reaction process is simple and rapid, few reagents are used, and the purity and the yield are greater than or equal to 95%; EDCI or DCC is selected as a condensation reagent; a mixed solvent is used for crystallization, the influence on product yield is small, and impurity removal effect is good; the overall technology adopts a one-step to synthetize, simple, efficient, high in atom economy, more green and environment-friendly, and the racecadotril product which is high in yield, and accords with the EP quality standard can be obtained.

The invention discloses a method for synthesis of 1-(4, 5-dihydro-2-thiazolinyl)-3-mercaptoazetidine hydrochloride. With 2-methylthio-2-thiazoline (I) as the raw material, the method of the invention comprises the steps of: in the presence of alkali, reacting 2-methylthio-2-thiazoline (I) with 3-hydroxyazetidine hydrochloride so as to obtain 1-(4, 5-dihydro-2-thiazolinyl)-3-hydroxyazetidine (II), and reacting (II) with methyl sulfonylchloride in the presence of alkali so as to obtain 1-(4, 5-dihydro-2-thiazolinyl)-3-methane sulfonate group azetidine (III), subjecting (III) to a reaction with potassium thioacetate so as to obtain 1-(4, 5-dihydro-2-thiazolinyl)-3-thioacetic acid ester group azetidine (IV), in the presence of alkali, subjecting (IV) to hydrolysis and then to acidification with dilute hydrochloric acid, thus obtaining the 1-(4, 5-dihydro-2-thiazolinyl)-3-mercaptoazetidine hydrochloride (V). With easily available and inexpensive starting material, the method of the invention simplifies the synthesis route, improves the raw material utilization ratio and the overall yield. An intermediate obtained in the reaction can be subjected to refinement by a recrystallization method or to a next reaction directly, so that the yield is high and the "three wastes" produced during the reaction process are few. In addition, with low cost, the method of the invention is beneficial for industrial production.

The invention discloses a synthesizing method of dithiothreitol. 1,4-butylene glycol is used as an initiating raw material and undergoes addition reaction with bromine at first to obtain 2,3-dibromo-1,4-butylene glycol; hydrolyzation under the catalyzation of alkali is carried out to obtain dioxirane; addition reaction with thioacetic acid is carried out to obtain dithiothreitol diacetate; and finally hydrolyzation under the catalyzation of alkali is carried out to obtain the dithiothreitol. The synthesizing method avoids the generation of dithiothreitol isomeride impurities, simplifies the product separation and purification, and can improve the yield rate, greatly reduce the production cost and is applicable to industrial production.

A method and compositions for sulfurizing at least one phosphite or thiophosphite linkage in an oligonucleotide. The methods employ a phenylacetyl disulfide reagent (known as PADS), phenylthioacetic acid (PTAA) in the presence or absence or N-alkyl imidazole in industrially preferred solvents or solvents that are derived from renewable resources. The use of PTAA eliminates the need to “age” the PADS solution prior to its use in sulfurization reactions.

The invention relates to substituted thioacetic acid salicylate derivatives; compositions comprising an effective amount of a substituted thioacetic acid salicylate derivative; and methods for treating or preventing an metabolic disease comprising the administration of an effective amount of a substituted thioacetic acid salicylate derivative.

The invention relates to a preparation process for high-purity low-arsenic hydroxyethylidene diphosphonic acid. The preparation process comprises the following steps: with phosphorus trichloride, acetic acid and ammonium thioacetate as raw materials, controlling process conditions at first, reacting acetic acid with phosphorus trichloride in a reaction vessel to produce hydroxyethylidene diphosphonic acid and adding ammonium thioacetate in the process of the reaction; and then subjecting an obtained material to concentration and air flushing to remove impurities, adding ammonium thioacetate and carrying out arsenic removal and centrifugation so as to obtain the high-purity low-arsenic hydroxyethylidene diphosphonic acid. According to the invention, scientific technology is employed for product purification, no other substance like a crystal nucleus and a crystallization promoter is added, so no new impurity is introduced. Hydroxyethylidene diphosphonic acid in the high-purity low-arsenic hydroxyethylidene diphosphonic acid prepared in the invention is more than 95%, and arsenic content in the high-purity low-arsenic hydroxyethylidene diphosphonic acid is less than 2 ppm; the preparation process overcomes problems in packaging, transporting and on-site application of liquid hydroxyethylidene diphosphonic acid and broadens the application fields of the high-purity low-arsenic hydroxyethylidene diphosphonic acid.

The invention provides a method for preparing substituted homotaurine from an alpha, beta-unsaturated amide. The method is characterized in that thioacetic acid and the alpha, beta-unsaturated amide undergo an addition reaction to produce corresponding 3-acetylthioacetamide and through reduction and oxidation, the substituted homotaurine is obtained. The method adopts simple and easily available raw materials, is convenient for operation, avoids a complicated desalting purification process, and is especially suitable for large-scale industrial production. The homotaurine can be used as a nutriment, a drug, an enzyme inhibitor, an antiseptic, a surfactant, a plant-growth regulator and a raw material of sulfonopeptides.

The invention discloses a preparation method and a production device of thioacetic acid. The thioacetic acid is obtained through carrying out low temperature reaction by adopting acetic acid and phosphorus pentasulfide under the action of a specific catalyst, carrying out solid-liquid separation, and carrying out distillation separation on a liquid phase. A solid-phase substance obtained through solid-liquid separation for the first time is further extracted and purified, so that a byproduct potassium phosphate is obtained. Low-price and easy-to-get raw materials and the catalyst are adopted and can be reacted to synthesize to obtain the thioacetic acid at lower temperature and pressure intensity and even at normal pressure and temperature, solid-liquid separation is carried out to obtainthe liquid phase, and the liquid phase is subjected to distillation separation so as to obtain the thioacetic acid with high purity and high yield. Through further extracting and purifying the solid-phase substance obtained through solid-liquid separation for the first time, the high-value-added byproduct potassium phosphate with high purity and high yield is obtained from the waste liquid, so that the preparation method is friendly to the environment and has higher economical efficiency.

The invention provides a catalyst-free excellent-regioselectivity weak-alkali-prommoted technique for synthesizing a phenothiazine intermediate. The method comprises the following step: in an inert atmosphere, 2-acetaminophenyl S-thioacetate and o-dihalogenated aromatic hydrocarbons directly react in the presence of a weak alkali to obtain the phenothiazine drug intermediate. The technique is green and environment-friendly, has higher reaction yield of the intermediate for most phenothiazines, and has industrialized application prospects.

A synthetic method of spironolactone belongs to the technical field of chemical synthesis. The method comprises the following steps: heating and refluxing for 3-5 hours to perform an addition reaction with canrenone and potassium thioacetate as raw materials and ethanol as a solvent in the presence of an acidic catalyst, after the reaction, cooling to -10 DEG C, performing heat preservation for 1.5-2.5 hours, filtering, treating the filter cake to obtain spironolactone, wherein the feeding molar ratio of canrenone, potassium thioacetate, and the acidic catalyst is 1:2.1:2.1. The invention adopts thiacetate instead of thioacetic acid, which effectively solves the environmental protection pressure caused by thioacetic acid, and reduces environment pollution; the method has a simple process, is easy to operate, and has high economic and environmental protection benefit; the invention mainly solves the technical problem of existing synthetic methods that the special smell of the raw material of thioacetic acid causes high environmental protection pressure for enterprises.

The invention discloses a preparation method of the thioacetic acid. The method is that the sodium sulphide produced by the carbon and the mirabilite is adopted to react with the hydrochloric acid to prepare the hydrogen sulfide, and then under the good air-tightness, the hydrogen sulphide gas processed by the dryer reacts with the acetic anhydride to gain the nearly colorless thioacetic acid with content not less than 95 per cent, boiling range of 88 DEG C. to 91DEG C., heavy metals less than 0.0002 per cent, melting point less than minus 17 DEG C. and flash point less than 1 DEG C. through reduced pressure distillation and rectification. The preparation method has convenient operation, which avoids the pollution on the external environment during production, greatly increases the purification of the product content and the product quality and lowers the production cost.

The invention relates to a preparation method of 3,7-dimethyl-3-acetylthio-6-octenol. The preparation method comprises the following steps: (1) stirring 3,7-dimethyl-3-acetylthio-6-octenal and sodiumborohydride in a mole ratio being 4:1-3:1 in an aqueous solvent at room temperature for reaction for 2-5 hours, and performing washing with an acid aqueous solution until pH is 7; (2) extracting a reaction solution washed to be neutral in the step (1) with an extracting agent, and drying and concentrating the extracted organic phase to obtain a crude product; (3) purifying the crude product obtained in step (2) to obtain a 3,7-dimethyl-3-acetylthio-6-octenol pure product. Compared with the prior art, the preparation method has the advantages of easily available raw materials, simple preparation process and low cost, and is convenient to operate, environmentally friendly and suitable for industrial production, and the problems of environmental unfriendliness, long reaction route and low yield which are caused by adoption of pyridine and thioacetic acid of traditional methods are solved.

The invention discloses a fly ash cured heavy metal chelating agent and a preparation process thereof and belongs to the field of chemical preparations. The fly ash cured heavy metal chelating agent is prepared from the following raw materials in parts by weight: 20-40 parts of a polycarboxylic acid ammonium salt, 20-30 parts of dimercaptoethylamine hydrochloride, 15-25 parts of amino methane acetate, 10-20 parts of sulfo-acetate, 30-50 parts of water, 5-10 parts of a surfactant, wherein the surfactant is prepared from the following raw materials in parts by weight: 5-30 parts of isopropyl alcohol amine, 10-40 parts of citric acid, 2-6 parts of a cosolvent and 5-20 parts of a dispersant. The chelating agent disclosed by the invention is not only simple to prepare and low in preparation cost, but also high in chelating efficiency, rich in chelating type and high in market application value.