24065-33-6Relevant articles and documents
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Bachman,Heisey
, p. 2378 (1948)
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Method for synthesizing 5-chlorothiophene-2-formic acid with thiophene-2-formic acid as raw material
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Paragraph 0027; 0031-0036, (2019/10/22)
The invention discloses a method for synthesizing 5-chlorothiophene-2-formic acid with thiophene-2-formic acid as a raw material. According to the method, the thiophene-2-formic acid is taken as a substrate, trichloroisocyanuric acid is taken as a chlorinating agent, and under an acidic condition, a substitution reaction is carried out to generate the 5-chlorothiophene-2-formic acid. The method isconcise, the operation is simple, the product is high in yield, industrial production is facilitated, raw materials are cheap, and the 5-chlorothiophene-2-formic acid has a wide use range and very high production application value.
Method for preparing 5-chlorothiophene-2-carboxylic acid through one-pot synthesis
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Paragraph 0027; 0029; 0030; 0032, (2018/12/13)
The invention relates to a method for preparing 5-chlorothiophene-2-carboxylic acid through one-pot synthesis. The method comprises the following steps: leading or adding a chlorinated reagent into 2-thiophenecarboxaldehyde for heat insulation reaction, so as to obtain an intermediate 5-chlorine2-thiophenecarboxaldehyde after the reaction is completed, wherein the intermediate 5-chlorine2-thiophenecarboxaldehyde is directly used for the next reaction without separation; slowly dropping the intermediate 5-chlorine2-thiophenecarboxaldehyde into pre-cooled caustic soda liquid, controlling the reaction temperature to be not higher than 30 DEG C, cooling after the dropping is completed, slowly leading chlorine into the pre-cooled caustic soda liquid for heat insulation reaction after the leading of the chlorine is completed, cooling to 5 DEG C after a center control reaction is completed, adding sodium sulfite for quenching, adding a solvent for extraction and impurities elimination, regulating the pH value of a water phase with concentrated hydrochloric acid, performing suction filtration, recrystallizing a filter cake, and drying, so as to obtain an target compound. According to the method, the defects of the prior art of being high in raw materials, complex in operation and more in three wastes are overcome; the provided method for synthesizing 5-chlorothiophene-2-carboxylic acidis suitable for industrial production.