4 results about "Methoxy-phenylacetic acid" patented technology

The invention belongs to the technical field of organic synthesis, and particularly relates to a method for synthesizing 3, 4-difluoro-2-methoxyphenylacetic acid without transition metal catalysis, which comprises the following steps: by taking 2, 3, 4-trifluoronitrobenzene as an initial raw material, carrying out substitution, methylation, reduction, Sandmeyer reaction, cross coupling, hydrolysis and other reactions, and synthesizing the 3, 4-difluoro-2-methoxyphenylacetic acid without transition metal catalysis. The total yield is 55.6%, and the content of the refined 3, 4-difluoro-2-methoxyphenylacetic acid reaches 99% or above. The method has the advantages of mild reaction conditions, simple operation, high reaction yield, easy purchase of used reagents and instruments, low cost, no need of any transition metal catalysis, and feasibility in specific practical application.

The invention belongs to the field of medicinal chemistry, and particularly provides a synthesis method of a key intermediate of suzertraline, 3, 4-difluoro-2-methoxybenzaldehyde is used as a starting material, and 3, 4-difluoro-2-methoxyphenylacetic acid is obtained through Wittig reaction, demethylation and aldehyde group oxidation. Compared with the prior art, the synthesis yield of the synthesized target compound is high, the synthesis process is simple to operate, the use of an expensive catalyst is avoided, the method is environment-friendly, the production is efficient, the synthesis purity is high, and factory amplification-scale production is facilitated.

This invention relates to the field of pharmaceutical intermediate synthesis, specifically to a method for synthesizing 3,4-difluoro-2-methoxyphenylacetic acid. The method includes the following steps: Compound III reacts with diethyl malonate in the presence of a copper catalyst, a nitrogen-containing ligand, and base I; then, an inorganic strong base II is directly added for hydrolysis, followed by acidification to obtain compound IV; compound IV undergoes decarboxylation in an acidic solution to yield 3,4-difluoro-2-methoxyphenylacetic acid (compound I) with a purity of up to 99.3% and an overall yield of up to 74.04%. This invention features a simple route, mild reaction conditions, low cost, environmental friendliness, stable yields at each step, and simple post-processing, making it suitable for industrial production.

This invention belongs to the field of organic synthesis technology and relates to a method for synthesizing 3,4-difluoro-2-methoxyphenylacetic acid, comprising the following steps: S1 Using 3,4-difluoro-2-methoxyaniline and a diazotizing reagent as raw materials, a diazotization reaction is carried out under the action of a copper catalyst and an inorganic acid to obtain the 3,4-difluoro-2-methoxyaniline diazonium salt; subsequently, a Sandmeyer reaction is performed with bromine to obtain 6-bromo-2,3-difluoroanisole; S2 The 6-bromo-2,3-difluoroanisole obtained in step S1 is reacted with diethyl malonate under the action of a ferricyanide to obtain 2-(3,4-difluoro-2-methoxyphenyl)malonic acid; S3 The 2-(3,4-difluoro-2-methoxyphenyl)malonic acid obtained in step S2 is reacted with concentrated sulfuric acid to obtain 3,4-difluoro-2-methoxyphenylacetic acid. This invention features mild reaction conditions, high yield, and high purity, making it suitable for industrial production.