4 results about "Ester hydrochloride" patented technology

This invention provides a method for preparing (S)-2-amino-4-chlorobutyric acid alkyl ester and its salt, comprising the following steps: (1) reacting a compound of formula I with a base to generate a compound of formula II; (2) reacting a compound of formula II with a chlorinating agent to generate a dichloride; and (3) reacting the dichloride with an alcohol to generate a compound of formula III. The preparation method of this invention improves the physicochemical properties of the reaction by constructing a dimer intermediate from the intramolecular bifunctional group of the compound of formula I, then achieving hydroxyl chlorination with a chlorinating agent, and finally, under the action of an alcohol, achieving the one-pot preparation of (S)-2-amino-4-chlorobutyric acid alkyl ester hydrochloride. This method effectively reduces the amount of chlorinating agent and alcohol used, significantly improves the atom economy and effective conversion rate of the reaction, has mild reaction conditions, produces products without significant racemization, has controllable impurities, and simplifies post-processing and purification. The by-product waste salt can be recycled, making it suitable for large-scale industrial production.

The application provides a synthesis method of an organic light response probe HBT-CN based on an ESIPT effect, the obtained probe and application thereof, and belongs to the technical field of biological probes.The 1R, 2R-cyclohexanediamine is used as a chiral recognition module, is connected to a 2-(2'-hydroxyphenyl)benzoxazole derivative fluorescent group through a simple amide reaction, and a kind of organic light response probe HBT-CN based on ESIPT effect is successfully designed and synthesized.The probe HBT-CN can realize enantiomer selective fluorescence recognition detection of amino acid ester hydrochloride by direct titration method.In addition, the probe can also be used for enantiomer selective detection through sensitive ratio type ultraviolet absorption change.The fluorescence and ultraviolet response difference of two enantiomers is shown by the research results, and the probe has high sensitivity and enantiomer distinguishing degree.

The application discloses a kind of (2-carboxyethyl) dimethyl sulfonium chloride and L-homoserine lactone hydrochloride coproduction method, it is related to organic chemistry technical field;Step is: acrylic acid, L-methionine is dissolved in deionized water, and solution A is obtained;Solution A is reacted with hydrochloric acid, distillation to no distillate under reduced pressure, cooling crystallization, filtration, and L-homoserine lactone hydrochloride is obtained;The filtrate of filtration is dissolved into organic solvent after distillation under reduced pressure, catalyst is added, and is reacted with methylating agent, then distillation to no distillate, add hydrochloric acid, cooling crystallization, filtration, and (2-carboxyethyl) dimethyl sulfonium chloride is obtained;The application uses L-methionine, acrylic acid and hydrochloric acid as raw materials, while preparing L-homoserine lactone hydrochloride, its byproduct beta-methylthiopropionic acid can further prepare (2-carboxyethyl) dimethyl sulfonium chloride, waste is treasure, improves raw material utilization, and three wastes are less, and production cost is low.

This invention relates to the field of feed additive preparation technology, and proposes a method for preparing ethyl guanidine hydrochloride, comprising the following steps: S1, dissolving glycine ethyl ester hydrochloride in a solvent, adjusting the pH to 10-11 at 0-5°C using an alkaline adjuster to obtain a reaction solution containing free glycine ethyl ester; S2, adding a cyanamide aqueous solution to the reaction solution containing free glycine ethyl ester at 0-5°C, and reacting at 55-80°C to obtain a reaction solution; S3, after cooling the reaction solution, adjusting the pH to 6-7 using an acidic adjuster, precipitating a solid, which is then filtered and washed to obtain crude ethyl guanidine hydrochloride; S4, recrystallizing the crude ethyl guanidine hydrochloride to obtain ethyl guanidine hydrochloride. This technical solution solves the problems of low yield and low purity of ethyl guanidine hydrochloride in related technologies.