95results about How to "Simplify purification operations" patented technology

An improved continuous process for converting methane, natural gas, and other hydrocarbon feedstocks into one or more higher hydrocarbons, methanol, amines, or other products comprises continuously cycling through hydrocarbon halogenation, product formation, product separation, and electrolytic regeneration of halogen, optionally using an improved electrolytic cell equipped with an oxygen depolarized cathode.

The invention discloses a method for chemically synthesising gastrodin, comprising the following steps of: in the presence of a molecular sieve, under the catalysis of Lewis acid, and performing glycosylation reaction on pent-acetyl-b-D-glucose and p-cresol in an organic solvent with to generate 4-methylphenyl-2,3,4,6-O-tetra-acetyl-b-D-glucopyranoside; then preparing 4-halomethylphenyl-2,3,4,6-O-tetra-acetyl-b-D-glucopyranoside from 4-methylphenyl-2,3,4,6-O-tetra-acetyl-b-D-glucopyranoside and N-halosuccinimide in the presence of an initiator, and then reacting 4-halomethylphenyl-2,3,4,6-O-tetra-acetyl-b-D-glucopyranoside with the mixed solution of glacial acetic acid and tertiary amine to obtain 4-acetoxylmethylphenyl-2,3,4,6-O-tetra-acetyl-b-D-glucopyranoside; and finally removing the acetyl protecting group from the 4-acetoxylmethylphenyl-2,3,4,6-O-tetra-acetyl-b-D-glucopyranoside in an alkaline condition to obtain gastrodin. Compared with the traditional method, the method disclosed by the invention has easily available raw materials, and is short in reaction time, capable of preparing the reaction product in each step via recrystallization, simple, and more suitable for industrialized production for gastrodin.

The invention relates to a tranexamic acid high-efficiency production method which comprises the following steps: performing hydrogenation reduction on 4-(acetylaminomethyl)benzoic acid used as an initial raw material, filtering the hydrogenation solution to remove a catalyst, distilling until the reaction solution is cured, heating, and baking to perform transformation; and dissolving with water, regulating the reaction solution to neutral with acid, adding p-toluenesulfonic acid to perform salification, filtering, performing resin exchange with a weak base anion-exchange resin, distilling the eluate until a large amount of solids are precipitated, adding a right amount of ethanol to crystallize, cooling, filtering, washing, and drying to obtain tranexamic acid. For the tranexamic acid produced by the method, the cis-compound content is lower than 0.05%, and the quality completely meets pharmacopeia standards at home and abroad and is higher than the quality of products currently reported in China. The production route provided by the invention has the advantages of fewer steps, simple operation process, high yield, energy saving, environment friendliness and the like.