摘要:
Process for purifying thioctic acid in water comprising the following steps: a) dissolving the thioctic acid in an aqueous alkaline solution or alternatively dissolving a thioctic acid salt, if necessary adjusting the pH to alkaline values, b) acidifying the solution from step (a) with an acid chosen from the class consisting of sulfuric acid, phosphoric acid, methanesulfonic acid to a pH between 5.4 and 5.8. c) isolating the thioctic acid precipitated in step (b) by conventional methods.
摘要:
In a process for the preparation of 4,5-diphenyloxazole-2-propanoic acid, the improvement consisting in using toluene in the esterification reaction of benzoin, and acetic acid/formic acid in the subsequent cyclization, thereby obtaining higher yields and avoiding the use and the disposal of high amounts of pyridine.
摘要:
Process for purifying thioctic acid in water comprising the following steps: a) dissolving the thioctic acid in an aqueous alkaline solution or alternatively dissolving a thioctic acid salt, if necessary adjusting the pH to alkaline values, b) acidifying the solution from step (a) with an acid chosen from the class consisting of sulfuric acid, phosphoric acid, methanesulfonic acid to a pH between 5.4 and 5.8. c) isolating the thioctic acid precipitated in step (b) by conventional methods.
摘要:
A process for the preparation of 5-(3,5-dimethylphenoxymethyl)-2-oxazolidinone, which includes: a) reacting 3,5-dimethylphonel with epichlorohydrin to obtain a mixture of 1-(3,5-dimethylphenoxy)2,3-epoxy propane (1) and 1-(3,5-dimethylphenoxy)-3-chloro-2-propanol (2); b) reacting the mixture of (1) and (2) obtained from step (a) with benzylamine to obtain a first compound; c) reducing the first compound with hydrogen in presence of ammonia, to obtain a second compound; and d) reacting the second compound with dimethylcarbonate in the presence of a strong base to obtain 5-(3,5-dimethlphenoxymethyl)-2-oxazolidinone.