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    • 9. 发明授权
    • Process for the preparation of thiophene-2-5-dicarboxylic acid and the
dichloride thereof
    • 噻吩-2,5-二羧酸及其二氯化物的制备方法
    • US5688969A
    • 1997-11-18
    • US751566
    • 1996-11-18
    • Ivan Orban
    • Ivan Orban
    • C07D333/40B01J31/02C07B61/00C07D333/38
    • C07D333/38
    • The invention relates to a process for the preparation of thiophene-2,5-dicarboxylic acid by reacting thionyl chloride and adipic acid, with pyridine as catalyst, which process comprises A) adding 1 part of adipic acid to 3 to 6 parts of thionyl chloride, mixed with a catalytic amount of pyridine, B) adding a further 4 to 7 parts of thionyl chloride in the temperature range from 85.degree. to 95.degree. C., C) removing excess thionyl chloride and volatile by-products under reduced pressure, and D) bringing the reaction to completion in the temperature range from 140.degree. to 160.degree. C., and E) preparing a salt of thiophene-2,5-dicarboxylic acid by hydrolysing the chloride obtained with an aqueous solution of an alkaline earth metal hydroxide or an alkali metal hydroxide, and F) obtaining the free acid from this salt with a mineral acid.
    • 本发明涉及通过亚硫酰氯和己二酸与吡啶反应制备噻吩-2,5-二羧酸的方法,该方法包括:A)将1份己二酸加入3至6份亚硫酰氯 与催化量的吡啶混合,B)在85℃〜95℃的温度范围内再加入4〜7份亚硫酰氯,C)在减压下除去过量的亚硫酰氯和挥发性副产物, D)使反应在140℃至160℃的温度范围内完成,E)通过水解由碱土金属氢氧化物水溶液获得的氯化物制备噻吩-2,5-二羧酸的盐 或碱金属氢氧化物,F)用无机酸从该盐得到游离酸。