| 摘要 |
PURPOSE: A method of preparing oxoquazepam is provided, which is an intermediate material for quazepam CONSTITUTION: A method of preparing oxoquazepam shown by the following formula (2), which comprises reacting 2,2,2-trifluoroethyl trifluoromethanesulfonate with 7-chloro-1,3-dihydro-5-(2-fluorophenyl)-2H-1,4-benzodiazepine-2-one shown by the following formula (1). Oxoquazepam used as an intermediate material for medicines must include only a small amount of impurities, in particular, only a small amount of analogous materials. Therefore, a method of preparing high purity oxoquazepam with a high yield has been demanded. Ethyl acetate or tetrahydrofuran may be used as a solvent. If a solvent having a polarity higher than that of these compounds such as acetone, acetonitrile, or dimethylformamide is used, O-alkylates are produced at about a 30% yield. If a solvent having a polarity lower than that of these compounds such as toluene is used, the reaction may scarcely proceed and the raw materials are left unreacted. It is preferable to use ethyl acetate or tetrahydrofuran in an amount so that the polarity of the solvent is not affected by the polarity of the solute, specifically, 5 times or more of 7-chloro-1,3-dihydro-5-(2-fluorophenyl)-2H-1,4-benzodiazepine-2-one.
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