会员体验
专利管家(专利管理)
工作空间(专利管理)
风险监控(情报监控)
数据分析(专利分析)
侵权分析(诉讼无效)
联系我们
交流群
官方交流:
QQ群: 891211   
微信请扫码    >>>
现在联系顾问~
热词
    • 5. 发明专利
    • METHOD OF 2-(BENZYL-SUBSTITUTED) AMINO-NITROBENZENE PREPARATION
    • CS272922B1
    • 1991-02-12
    • CS18289
    • 1989-01-10
    • VEJDELEK ZDENEKKMONICEK VOJTECHKREPELKA JIRI
    • VEJDELEK ZDENEK ING CSCKMONICEK VOJTECH INGKREPELKA JIRI ING CSC
    • C07C211/29
    • The invention concerns the method of preparation of 2-(benzyl-substituted)-amino-nitrobenzene of general formula I, where R represents an atom of hydrogen, halogen, the nitro group, one methoxyl group or two methoxyl groups, whereas these compounds are important intermediate products, for example in the synthesis of benzimidazole derivatives blocking periphery H1-receptors and used for the therapy of allergy illnesses, as shown by the case of astemizole (Hismanal Janssen).The new method of preparing substances of formula I is based on the fact that 2-nitraniline is allowed to react with benzylhalogenide of general formula VI, where Hal represents the atom of chlorine or bromine and R has the same meaning as in formula I. The reaction occurs in the heterogeneous environment of the solution system, whose first phase is formed by benzene, toluene or xylene and the second by free aqueous 45 to 50 % sodium or potassium hydroxide; whereas for 1 mol of 2-nitraniline 4.5 to 5.0 mol sodium or potassium hydroxide is used, quaternary ammonium salt is added as a catalyst of the phase transformation. The reaction mixture is heated while mixing for 10 - 12 hours to the temperature of backflow and, after the reaction stops, the solvent is distilled from the separated organic part and the substance is thus isolated. Triethylbenzyl ammonium chloride can be used as a catalyst. Yields fluctuate above 70 % of the required product of general formula I.