A kind of method for preparing 2-amino-5-alkyl-1,3,4-thiadiazole

Abstract

The invention discloses a method for preparing 2-amino-5-alkyl-1,3,4-thiadiazole. The method comprises the following steps of adding A mol of thiosemicarbazide, B mol of carboxylic acid, C mol of phosphorus oxychloride and D mol of silica gel in a dry reaction container, grinding at a room temperature until the raw materials are completely reacted, and standing to obtain a crude product, wherein A: B: C = 1: (1 to 1.2): (1 to 1.2), and A: D = 1: (5 to 10); then adding alkaline solution in the crude product until the pH value of the obtained mixed solution is 8-8.2, then carrying out suction filtration on the mixed solution, dissolving the filter cake by a solvent and then further carrying out suction filtration, removing silica gel, then carrying out reduced pressure concentration on the finally-obtained filtrate, and removing the solvent to obtain 2-amino-5-alkyl-1,3,4-thiadiazole. The method disclosed by the invention is a solid-phase reaction, silica gel is used as a carrier, the operation process is simple, the reaction time is short, the reaction conditions are moderate, the equipment requirements are low, and the yield of the target product is up to more than 91%.

Description

technical field [0001] The invention belongs to the field of chemical synthesis, in particular to a method for preparing 2-amino-5-alkyl-1,3,4-thiadiazole. Background technique [0002] Thiadiazole compounds are five-membered heterocyclic compounds containing N and S atoms. They have obvious conjugation effect and aromaticity. The substituents at the 2 and 5 positions can participate in many chemical reactions. They are important in organic synthesis and medicinal chemistry. important intermediates. Thiadiazole derivatives have a wide range of physiological activities, such compounds have anticancer, antibacterial, antiviral, antispasmodic, antifungal and other activities. For a long time, the synthesis and activity research of 1,3,4-thiadiazole compounds have been concerned. [0003] Yang Ruisheng and others synthesized 2,5-substituted-1,3,4-oxadiazole-2-methylenethio-5-pyridin-3-yl-1,3,4-thiadiazole, and studied it by MTT method The target compound inhibits the activity...

AI Technical Summary

Problems solved by technology

The traditional method of preparing 2,5-substituted-1,3,4-thiadiazoles is synthesized in liquid phase, which has long reaction time, complex operation, high equipment requirements and low yield

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