46232-97-7

Upstream product

• 23849-12-9 methyl 2-(4-bromophenoxy)propanoate 
• 32019-08-2 (+/-)-2-(4-bromophenoxy)propanoic acid 
• 106-41-2 4-bromo-phenol 
• 59621-75-9 ethyl (+/-)-2-(4-bromophenoxy)propanoate 
• 108-95-2 phenol 
• 1129-46-0 (R)-(+)-2-phenoxypropionic acid 
• 73246-45-4 methyl-(S)-2-chloropropionate 

Downstream Products

• 94050-90-5 (R)-2-(4-hydroxyphenoxy)propionic acid 

Relevant academic research and scientific papers

Preparation method of (R)-(+)-2-(4-hydroxyphenoxy) propionic acid

The invention provides a preparation method of (R)-(+)-2-(4-hydroxyphenoxy) propionic acid, and belongs to the technical field of pesticide intermediates. Phenol compounds (parachlorophenol, p-bromophenol, p-iodophenol or p-hydroxybenzenesulfonic acid) are adopted as raw materials and react with (S)-(-)-2-chloropropionic acid to synthesize R-(+)-2-(4-chlorophenoxy) propionic acid, and the (R)-(+)-2-(4-hydroxyphenoxy) propionic acid is obtained after hydrogen hydrolysis. The raw material phenol compound used in the invention is low in price and simple in process operation; and the method avoids using hydroquinone as a raw material, and solves the problems of high raw material cost, difficult product purification and low product quality caused by hydroquinone disubstituted impurities generated in the reaction when hydroquinone is used as a raw material for synthesis in the traditional method.

Preparation method for R-(+)-2-(4-hydroxyphenoxy)propionic acid

The invention discloses a preparation method for R-(+)-2-(4-hydroxyphenoxy)propionic acid. The method comprises the following steps: mixing phenol and S-2-chloropropionic acid or a salt of the S-2-chloropropionic acid, water and a first catalyst in a closed environment, and under the protection of an inert gas, performing heating and an alkylation reaction to prepare 2-phenoxypropionic acid; mixing the 2-phenoxypropionic acid, a second catalyst and a halogenating agent, and performing a reaction at 20-30 DEG C to prepare 2-(4-halogenated phenoxy)propionic acid; and performing a micro-pressurereaction on the 2-(4-halogenated phenoxy)propionic acid, an alkali solution and a third catalyst at 150-160 DEG C in a sealed environment, after the reaction is completed, performing filtration, and performing acidification treatment to obtain the R-(+)-2-(4-hydroxyphenoxy)propionic acid. The method provided by the invention uses the phenol and the organic acid or the organic acid salt as raw materials, and has simple purification and high purity of the product.

SUBSTITUTED AMINO TRIAZOLES, AND METHODS USING SAME

Disclosed are novel substituted amino triazoles of Formula (I), and pharmaceutically acceptable salts thereof. The compounds of Formula (I) are inhibitors of Acidic mammalian chitinase (AMCase) and are useful, in a non-limiting example, for treating asthma. Also provided are pharmaceutical compositions containing at least one compound of the present invention, or a pharmaceutically acceptable salt, hydrate or solvate thereof, and at least one pharmaceutically acceptable carrier, solvent, adjuvant or diluent, and methods of using such compounds and/or compositions to treat asthma and/or to monitor asthma treatment.

Enantioselective hydrolysis of some 2-aryloxyalkanoic acid methyl esters and isosteric analogues using a penicillin G acylase-based HPLC monolithic silica column

A technique based on liquid chromatography has been developed to facilitate studies of enantioselectivity in penicillin G acylase (PGA)-catalyzed hydrolysis of some 2-aryloxyalkanoic acid methyl esters and isosteric analogues. PGA was covalently immobilized on an aminopropyl monolithic silica support to create an immobilized HPLC-enzyme reactor. Two sets of experimental data were drawn to calculate the enantioselectivity (E) of the kinetically controlled enantiomer-differentiating reaction, the degree of substrate conversion and the enantiomeric excess of the product. The developed enzymatic reactor was coupled through a switching valve to an achiral analytical column for separation and quantitation of the hydrolysis products. The enantiomeric excess was determined off-line on a PGA-chiral stationary phase. In this way, highly precise E values were determined. A computational study related to the hydrolysis of the considered racemic esters was also carried out in order to unambiguously clarify both the substrate specificity and the enantioselectivity displayed by PGA.

Microbial deracemization of α-substituted carboxylic acids: Substrate specificity and mechanistic investigation

A new enzymatic method for the preparation of optically active α-substituted carboxylic acids is reported. This technique is called deracemization reaction, which provides us with a route to obtain the enantiomerically pure compounds, theoretically in 100% yield starting from the racemic mixture. This means that the synthesis of a racemate is almost equal to the synthesis of the optically active compound, and this concept is entirely different from the commonly accepted one in the asymmetric synthesis. Using the growing cell system of Nocardia diaphanozonaria JCM3208, racemates of 2-aryl- and 2-aryloxypropanoic acid are deracemized smoothly and (R)-form-enriched products are recovered in high chemical yield (>50%). In addition, using optically active starting compounds and deuterated derivatives as well as inhibitors, we have disclosed the fact that a new type of enzyme takes part in this biotransformation, and that the reaction proceeds probably via the same mechanism as that in rat liver.

Microbial deracemization of alpha-substituted carboxylic acids.

An enzyme system of Nocardia diaphanozonaria JCM 3208 catalyzes the inversion of the chirality of various alpha-substituted carboxylic acids, such as 2-phenylpropanoic acid and 2-phenoxypropanoic acid derivatives, via a novel deracemization reaction.

Candida cylindracea lipase-mediated kinetic resolution of α-substituted α-aryloxyacetic acid methyl esters

Hydrolysis of several α-alkyl-α-aryloxyacetic acid methyl esters and of α-methyl-α-(n-propyl)-α-(p-chlorophenoxy)acetic acid methyl ester were performed in the presence of Candida cylindracea lipase. The α-alkyl-α-aryloxyacetic acid methyl esters and α-methyl-α-(n-propyl)-α-(p-chlorophenoxy)acetic acid methyl ester were incubated in buffer phosphate (pH 7-8). The reaction mixture, containing the unreacted ester and corresponding acid, showed enantiomeric excesses (ee) up to 81%. The extent of conversion was quite low for the α-methyl-α-(n-propyl)-α-(p-chlorophenoxy)acetic acid methyl ester, the corresponding acid was obtained with ee > 98%.