摘要:
The subject of the present invention is the preparation of the (R)-(−)-2-hydroxy-2-(2-chlorophenyl)acetic acid of the formula (I) by the resolution of the corresponding racemic compound by using the compounds of the general formula (II).
摘要:
2,5-dihydroxyterephthalic acid is produced in high yields and high purity from 2,5-dihaloterephthalic acid by contact with a copper source and a ligand that coordinates to copper under basic conditions.
摘要:
2,5-dihydroxyterephthalic acid is produced in high yields and high purity from 2,5-dihaloterephthalic acid by contact with a copper source and a ligand that coordinates to copper under basic conditions.
摘要:
A process for the manufacture of oxalic acid dihydrate in which an aqueous solution of sodium oxalate is contacted with hydrochloric acid and the resulting mixture then cooled to precipitate oxalic acid, followed by optional recovery and recycling of the sodium oxalate and hydrochloric acid into the reaction chamber.
摘要:
The present invention provides a method for producing optically active flurbiprofen. The method of the present invention includes mixing racemic flurbiprofen and (S)- or (R)-3-methyl-2-phenylbutylamine in an organic solvent to produce a diastereomeric salt; and treating the diastereomeric salt with an acid in a second solvent. In the method of the present invention, flurbiprofen having a desired absolute configuration can be obtained very efficiently without repeating the procedure for optical resolution a plurality of times.
摘要:
A fluorocarboxylic acid preparation process continuously carries out acidification reaction treatment and washing treatment, and includes subjecting a fluorocarboxylate-containing aqueous solution to acidification reaction treatment in the presence of sulfuric acid so as to form a sulfate-containing fluorocarboxylic acid phase; and subjecting the fluorocarboxylic acid phase to washing treatment using an aqueous sulfuric acid solution.
摘要:
A process for the recovery of organic acids from dilute solutions such as those produced by fermentation, when the organic acids are present as dilute salt solutions, is provided. The organic acid production process is integrated with a nitrogen fertilizer production process by utilizing wasted chemical energy from the fertilizer process for acidification of the organic acid solution.
摘要:
The invention aims at producing high-purity crystals of a hydroxycarboxylic acid represented by the following formula (1): in high yield. Provided are a method for crystallization of a compound (1) which comprises acidifying a mixture of a solution of an alkali salt of the compound (1) and an organic solvent, and a method for crystallization of compound (1) by mixing a solution of the compound (1) in a water-miscible good solvent with water, in which a slurry with a necessary suspension amount of the compound (1) for inhibiting oil formation and scaling is prepared in advance and then a main crystallization is carried out in the presence of said slurry.
摘要:
In the process for the continuous recovery of free tartaric acid from raw materials containing potassium hydrogentartrate, the same are mixed with water and the potassium hydrogentartrate is dissolved. The process is improved in that the suspension is decanted, the clarified liquid is refiltered, the filtrate is cooled to crystallization temperature under a vacuum, the potassium hydrogentartrate crystals formed are dissolved, the solution is subject to a cation exchange, and the tartaric acid solution obtained is evaporated.
摘要:
Processes for preparing carboxylic acids and derivatives thereof in which an ammonium salt of the carboxylic acid is heated in the presence of an organic reagent to split the salt and form the acid or, where the organic reagent is an esterifying agent, the corresponding ester. Both the acid and the ester may be dehydrated to form unsaturated counterparts.