11 results about "Methoxy-phenylacetic acid" patented technology

The invention discloses a preparation method of 3, 4-difluoro-2-methoxyphenylacetic acid, and belongs to the technical field of organic synthesis. The preparation method comprises the following steps: reacting 2, 3-difluorophenol with 3, 4-dihydropyran under the action of sulfonic acid resin to generate an intermediate 2-(2, 3-difluorophenoxy) pyran; then lithiating, reacting with tert-butyl 2-bromoacetate, and performing acidolysis to obtain a 3, 4-difluoro-2-hydroxyphenylacetic acid intermediate; and finally reacting with a methylation reagent in the presence of alkali to generate the target compound 3, 4-difluoro-2-methoxyphenylacetic acid. The preparation method has the advantages that the route is overall reasonable, the preparation method comprises three steps, and a simple and effective new route is provided for the preparation of the 3, 4-difluoro-2-methoxyphenylacetic acid.

The invention relates to a suzertraline intermediate as well as a preparation method and application thereof, and particularly provides a suzertraline intermediate 3, 4-difluoro-2-methoxyphenylacetic acid compound and a preparation method thereof, and the suzertraline intermediate can be used for preparing 3, 4-difluoro-2-methoxyphenylacetic acid. Specifically, 2, 3, 4-trifluoronitrobenzene which is low in price and easy to obtain serves as a starting raw material, 3, 4-difluoro-2-methoxyphenylacetic acid is prepared through a substitution reaction, a methylation reaction, a reduction reaction, a Meerwein arylation reaction and a hydrolysis reaction, the method is mild in reaction condition, a reaction substrate better meets the economic and environment-friendly requirements, reaction operation and a post-treatment process are safe and simple, and the method is suitable for industrial production. The purification steps are simple and convenient, byproducts are few, a target product with high purity can be obtained conveniently, corrosion to equipment is small, special equipment is not needed, and the method is suitable for industrial production.

The present invention provides a method for preparing enantiopure α-methoxyphenylacetic acid. The method comprises: using (R / S)-mandelic acid as the main raw material, performing an O-alkylation reaction with a methylating agent in the presence of an alkaline reagent, followed by purification and dissociation using an organic base to obtain enantiopure α-methoxyphenylacetic acid with a purity of up to 99.0%. The method achieves a maximum yield of 88.6% in an aprotic mixed solvent. This process reduces the amount of methylating agent used and increases the conversion rate to 99.5%. The organic base salt formation purification is efficient, produces a good crystal form, and is easily filtered. The process is simple, highly safe, and suitable for industrial-scale production.

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 discloses a process method for synthesizing (S)-(+)-1-aminoindene, and belongs to the technical field of medical intermediates. According to the method, 1-indanone is taken as a raw material, the raw material and an ammonia-methanol solution are subjected to an ammoniation reduction reaction to generate 1-aminoindane, and then (S)-(+)-alpha-methoxyphenylacetic acid is subjected to salifying resolution to generate (S)-(+)-1-aminoindene. The method has the advantages of good selectivity, high yield and easiness in operation, has potential technical advantages and is suitable for industrial large-scale production; the problems of low yield, tedious steps, difficult product purification and poor selectivity in other routes are avoided.

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.

The invention relates to a preparation method and application of 3, 4-difluoro-2-methoxyphenylacetic acid, 2, 3, 4-trifluoronitrobenzene is used as a starting material, 3, 4-difluoro-2-methoxyaniline is obtained through hydrolysis, alkylation and reduction hydrogenation, then the 3, 4-difluoro-2-methoxyaniline is subjected to a coupling reaction, a hydrolysis reaction and an oxidation reaction, and a key intermediate 3, 4-difluoro-2-methoxyphenylacetic acid is obtained. The preparation method has the advantages of simple process flow, mild reaction conditions, high reaction safety coefficient, short reaction time, high yield, single reaction site of each reaction, few by-products, and facilitation of the obtaining of a high-purity target product, the intermediate compound can be obtained only through extraction and concentration in most of the post-treatment, and the method is suitable for industrial production. The 3, 4-difluoro-2-methoxyphenylacetic acid prepared by the method has the advantages of simple process, no need of tedious means for purification, low emission of generated wastewater and waste gas, meeting of the requirements of green chemistry and environmental protection, low production cost, and suitableness for industrial application in production of suzertraline drugs.

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.

The invention belongs to the technical field of synthetic methods of natural products, and particularly relates to a novel total synthesis method of natural products such as medipterocarpin and Vissivoxel. According to the method, resorcinol and 2, 4-dimethoxyphenylacetic acid are taken as initial raw materials, and natural products such as medipterocarpin and visivoxel are respectively obtained through a Friedel-Crafts alkylation reaction, a substitution reaction, a cyclization reaction, a demethylation / cyclization cascade reaction and a hydrogenation reduction reaction; the key steps of the method are synthesis of a pterocarpin skeleton through a demethylation / cyclization cascade reaction one-pot method of isoflavone and palladium-carbon hydrogenation reduction reaction of pterocarpin. The method is novel and reasonable in design thought, simple and easily available in raw materials, simple and efficient in route and high in reaction yield, and has very high application value.

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.

The invention discloses a synthesis process of 5-methoxy laudanin tartrate, which is characterized in that 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride is added for catalytic reaction, 3, 4, 5-trimethoxy phenylacetic acid and 3, 4-dimethoxy phenylethylamine react in dichloromethane at 25 DEG C to obtain a condensation product, the reaction temperature is greatly reduced, and the reaction time is greatly shortened. In the ring closing reaction, purification and crystallization are carried out in a methanol and water system, and a product is obtained after direct filtration, so that the reaction yield is improved, and the operation is simplified; according to the method, acetic acid and formaldehyde are added for reaction, then sodium borohydride is used for reduction, so that the reaction can be well carried out, relatively pure 5-methoxylavatianin is obtained, and then the 5-methoxylavatianin and tartaric acid are salified to form a solid which can be stably stored.