5 results about "Diethyl azodicarboxylate" patented technology

The invention discloses a synthesis method of (S)-3-aminotetrahydrofuran, which comprises the following steps: (1) reacting (R)-3-hydroxytetrahydrofuran with phthalimide, triphenylphosphine and diethyl azodicarboxylate in tetrahydrofuran to obtain a condensation product; and (2) reacting the condensation product obtained in the step (1) with a methylamine-ethanol solution, or reacting with hydrazine hydrate in methanol to obtain (S)-3-aminotetrahydrofuran. The method is efficient, low in cost and environmentally friendly, has the advantages of simple process, mild conditions, high yield, easily available raw materials and the like, provides a feasible technical scheme for industrial production of (S)-3-aminotetrahydrofuran, and has a good application prospect.

The invention belongs to the technical field of manufacturing of optoelectronic devices, and particularly relates to a stripping liquid additive for recycling waste liquid and a preparation method of the stripping liquid additive. The preparation method comprises the following steps: (1) reacting benzotriazole, concentrated hydrochloric acid and paraformaldehyde to obtain a first intermediate product; (2) mixing the first intermediate product, N, N-dimethylethylenediamine, anhydrous acetonitrile and an acid-binding agent, carrying out heating reaction under the protection of nitrogen, cooling to room temperature, and carrying out suction filtration, purification and vacuum drying to obtain a second intermediate product; and (3) mixing the second intermediate product, polyethylene glycol monomethyl ether, triphenylphosphine and anhydrous tetrahydrofuran, dropwise adding a toluene solution of diethyl azodicarboxylate, reacting, carrying out reduced pressure distillation, adding diethyl ether, separating out a solid, carrying out suction filtration, concentrating the filtrate, and carrying out purification, reduced pressure distillation and vacuum drying. The additive can improve the efficiency and effect of the stripping liquid, and is low in corrosivity.

The present invention belongs to the technical field of polymer materials and relates to a method for preparing an amino-terminated hyperbranched polysulfide, comprising: stirring and dissolving a primary amine and 2,4-dinitrobenzenesulfonyl chloride in a solvent, heating, and keeping the temperature for 30 to 90 minutes; adjusting the temperature to 70 to 125° C., adding a primary alcohol, triphenylphosphine / diethyl azodicarboxylate as an initiator, adding thioglycolic acid, and keeping the temperature for 1 to 5 hours; removing the solvent to obtain a secondary amine and 2,4-dinitrobenzenesulfide; stirring and dissolving 2,4-dinitrobenzenesulfide in an acidic solvent, heating, adding iron powder, and keeping the temperature, removing the solid and solvent to obtain 2,4-diaminophenylenesulfide, stirring and dissolving 2,4-diaminophenylenesulfide in a solvent, heating, adding a catalyst, and keeping the temperature for 1 to 6 hours, and removing the solvent. The amino-terminated hyperbranched polysulfide obtained by the present invention is used to prepare hyperbranched internally cross-linked modified polyurethane.

This invention relates to a method for the direct synthesis of Aramchol from cholic acid, belonging to the field of organic synthesis technology. The key technical point of this invention is the method for the direct synthesis of Aramchol from cholic acid. First, eicosanoyl chloride is prepared from arachidic acid and thionyl chloride. Then, eicosanoamide is prepared from eicosanoyl chloride and ammonia-methanol solution. The eicosanoamide is added to tetrahydrofuran, followed by the addition of cholic acid, diethyl azodicarbonate, and triphenylphosphine. Aramchol is synthesized under the action of diethyl azodicarbonate and triphenylphosphine. This method overcomes the shortcomings of existing techniques for synthesizing Aramchol from cholic acid, such as excessively long reaction routes, large consumption of sodium azide and eicosanoyl chloride, complex side reactions, and poor reproducibility. The preparation method involves reactions at room temperature, is simple to operate, has short steps, convenient post-processing, and high yield, making it suitable for industrial application.

The invention discloses a preparation method of a Linzagolix intermediate, which comprises the following steps: under an alkaline condition and the action of an organic phosphorus ligand, 2, 3-difluoro-6-methoxybenzyl alcohol and 2-methoxy-4-fluorophenol are subjected to a Mitsunobu reaction to obtain 1, 2-difluoro-3-(4-fluoro-2-methoxyphenoxy methyl)-4-methoxybenzene, and the 1, 2-difluoro-3-(4-fluoro-2-methoxyphenoxy methyl)-4-methoxybenzene is subjected to the Mitsunobu reaction to obtain 1, 2-difluoro-3-(4-fluoro-2-methoxyphenoxy methyl)-4-methoxybenzene and the 1, 2-difluoro-3-(4-fluoro-2-methoxyphenoxy methyl)-4-methoxybenzene. Wherein the alkali for providing the alkaline condition is selected from one or more of N, N-diisopropylethylamine, triethylamine, 4-dimethylaminopyridine, diethyl azodicarboxylate and diisopropyl azodicarboxylate; the organic phosphine ligand is selected from one or more of triphenylphosphine, tri-tert-butylphosphine and (1, 2-bis (ethoxycarbonyl) hydrazino) triphenylphosphine trifluoromethanesulfonate, and the organic phosphine ligand is selected from one or more of triphenylphosphine, tri-tert-butylphosphine and (1, 2-bis (ethoxycarbonyl) hydrazino) triphenylphosphine trifluoromethanesulfonate. According to the method, the reaction steps are reduced, the production period is shortened, the total production cost is reduced, and the highest product yield can reach 90% or above.