94050-90-5Relevant articles and documents
Preparation method of (R)-(+)-2-(4-hydroxyphenoxy) propionic acid
-
Paragraph 0052; 0054-0055; 0057-0058; 0060-0061; 0063, (2021/05/19)
The invention provides a preparation method of (R)-(+)-2-(4-hydroxyphenoxy) propionic acid, and belongs to the technical field of pesticide intermediate preparation. According to the method, phenol is used as a raw material, phenol and (S)-(-)-2-halogenated propionic acid react to synthesize R-(+)-2-phenoxypropionic acid, and (R)-(+)-2-(4-hydroxyphenoxy) propionic acid is obtained after oxidation. According to the invention, the raw material phenol used in the method is low in price, the procedure operation is simple, use of hydroquinone as the raw material is avoided, and the problems of high raw material cost, difficult product purification, low yield, low product quality and need of recovery of the raw material hydroquinone caused by hydroquinone disubstituted impurities generated in the reaction when hydroquinone is used as the raw material for synthesis in the traditional method are solved; and results of the embodiment show that the yield of the (R)-(+)-2-(4-hydroxyphenoxy) propionic acid prepared by the method is greater than 85%, the liquid phase content is greater than or equal to 99.5%, the optical purity e.e is greater than 99.0%, and the product is high in yield and good in quality.
Preparation method of R-(+)-2-(4-hydroxyphenoxy) propionic acid
-
, (2021/05/05)
The invention relates to the technical field of organic synthesis, in particular to a preparation method of R-(+)-2-(4-hydroxyphenoxy) propionic acid. The preparation method provided by the invention comprises the following steps that p-nitrophenol and (S)-(-)-2-chloropropionic acid are subjected to substitution reaction under an alkaline condition to obtain R-(+)-2-(4-nitrophenoxy) propionic acid; the R-(+)-2-(4-nitrophenoxy) propionic acid and H2 are subjected to a reduction reaction under the catalysis condition of a catalyst, and the R-(+)-2-(4-aminophenoxy) propionic acid is obtained; and the R-(+)-2-(4-aminophenoxy) propionic acid and sodium nitrite are subjected to a diazotization hydrolysis reaction under the acidic condition, and the R-(+)-2-(4-hydroxyphenoxy) propionic acid is obtained. The preparation method is simple, easy to obtain and low in cost, and the prepared R-(+)-2-(4-hydroxyphenoxy) propionic acid is high in yield and high in purity.
Method for synthesizing R-(+)-2-(4-hydroxyphenoxy)propionic acid through gas phase catalysis
-
Paragraph 0015-0025, (2020/06/09)
The invention discloses a method for synthesizing R-(+)-2-(4-hydroxyphenoxy)propionic acid through gas phase catalysis, and belongs to the field of organic synthesis. Hydroquinone and D-lactic acid are used as raw materials, and nitrogen is used as a carrier gas. The hydroquinone and the D-lactic acid are completely gasified and then enter a fixed bed reactor, and the R-(+)-2-(4-hydroxyphenoxy)propionic acid is continuously synthesized in a gas phase under the catalysis of a supported heteropolyacid catalyst. The method has the advantages of mild reaction conditions, simple reaction process, high effective conversion rate of hydroquinone and high selectivity of the R-(+)-2-(4-hydroxyphenoxy) propionic acid, and is completely suitable for industrial production, and the self-made supported heteropolyacid solid catalyst has excellent catalytic activity, strong acidity, good stability and no pollution to the environment, and is a green catalyst.