49 results about "2-Methoxyethanol" patented technology

An improved synthesis method for preparation of iodixanol, and a purification process through macroporous adsorption resin chromatographic column and recrystallization are provided. The synthesis method relates to dimerization of 5-acetamido-N, N'-bis(2,3-dihydroxypropyl)-2,4,6- triiodo-isophthalamide (compound A) to prepare iodixanol, wherein excessive side reactions such as alkylation are effectively inhibited by controlling the pH of the reaction mixture with a boron-containing acidic substance or salts thereof such as boric acid. In this way, the conversion rate of compound A to iodixanol is 85-90%. The iodixanol crude product is purified by a macroporous adsorption resin chromatographic column, obtaining iodixanol product with recovery of 90-95% and purity of 96-98%. The iodixanol crude product is recrystallized in mixed solvent containing 2-methoxyethanol, obtaining iodixanol product with recovery of 90-95% and purity of greater than 99%.

The invention relates to a preparation method of bromfenac sodium. The preparation method comprises the following steps of (a) reacting a compound represented by a formula (V) with an electrophilic substitutional reagent in the presence of N,N-dimethylformamide or dimethyl sulfoxide to obtain a compound represented by a formula (IV), (b) adding the compound represented by the formula (IV) into 2-methoxyethanol, adding phosphoric acid and carrying out acid hydrolysis to obtain a compound represented by a formula (III), (c) hydrolyzing the compound represented by the formula (III) with sodium hydroxide, extracting with dichloromethane and adding acetic acid to neutralize to obtain a compound represented by a formula (II) and (d) in the presence of an organic alcohol solvent, adding a sodium hydroxide solution, hydrolyzing the compound represented by the formula (II) to form a salt, adding the organic alcohol solvent, cooling and crystallizing to obtain bromfenac sodium. According to the preparation method disclosed by the invention, the reaction yield of the intermediate (IV) and the quality of the product are improved, high-purity bromfenac sodium can be obtained just by virtue of crystallizing with the organic alcohol solvent, the good environmental benefit is achieved and the generation of bromfenac sodium polymer impurity is reduced.

The ether compound represented by formula (3) (where R represents an alkyl group having 1 to 6 carbon atoms) can be prepared by the following method, which includes: Step A: In 2-methoxyethanol, the formula (1 ) (where n represents an integer from 0 to 5, X represents a halogen atom, an alkyl group with 1 to 3 carbon atoms, cyano, nitro or trifluoromethyl) and a compound with 1 to 6 carbon atoms Metal alkane thiolate reaction; step B: adding water and a hydrocarbon solvent having 5 to 8 carbon atoms to the reaction mixture obtained in step A, and separating the organic layer; step C: from the reaction mixture obtained in step B The solvent is distilled off in the organic layer to prepare bis(alkylthiomethyl) ether; and step D: the bis(alkylthiomethyl) ether obtained in step C is mixed with 2- Cyanoethanol reacts with halogenating agents.