- Preparation method of ofloxacin impurity D
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The invention discloses a preparation method of ofloxacin impurity D, and belongs to the field of medicine synthesis. The preparation method has the advantages that the whole technology design is reasonable, the operability is strong, and the purifying is convenient. The preparation method is characterized in that oxygen-fluorine acid is used as an initiating raw material, and is performed with six-step reaction, so as to synthesize the ofloxacin impurity D. The ofloxacin impurity D prepared by the preparation method has the advantages that by screening the optimum preparation steps and reaction conditions through experiment, the purity can reach 99.5% or above; a testing sample is provided for the study of ofloxacin, and the important study value is realized in the clinical pharmacokinetic study.
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Paragraph 0022; 0031; 0032
(2018/04/02)
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- Synthesis method of levofloxacin isomer compound
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The invention provides a synthesis method of a levofloxacin isomer (-)-(S)-3-methyl-10-chloro-2, 3-dihydro-9-(4-methyl-1-piperazinyl)-7-oxo-7H-pyridino-[1, 2, 3-de]-[1, 4] benzoxazine-6-carboxylic acid. The method comprises the following steps: a, preparation of a compound M1: taking levofloxacin acid ester as a raw material, and performing nitratlon reaction in a concentrated sulfuric acid, nitric acid or nitrate condition; b, preparation of a compound M2: adding N-methyl piperazine into the compound M1, so as to perform piperazine retraction reaction; c, preparation of a compound M3: reducing nitro in the compound M2 into amino with a reducing agent; d, preparation of a compound M4: converting the amino in the compound M3 into hydrogen atom; e, preparation of the levofloxacin isomer: performing esterolysis on the compound M4 in an acidic or alkaline condition. The invention provides a novel synthesis method of the levofloxacin isomer, thereby providing a preparation method of a comparison product for the quality research of levofloxacin, and further providing important guiding significance for the safe medication of levofloxacin.
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Paragraph 0055; 0056
(2017/09/01)
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