52431-30-8

Light Orange Solid

Reatant in the synthesis of bromodinitro compound, polymers via stille coupling. 3,4-diaminothiophene was obtained from the reduction of 2,5-dibromo-3,4-dinitrothiophene.

GENERAL STEPS: Preparation The synthesis of 2,5-dibromo-3,4-dinitrothiophene from 2,5-dibromothiophene in Example 1 was carried out as follows: firstly, a mixed acid was prepared by mixing 11 mL of fuming nitric acid with 20 mL of fuming sulfuric acid. Subsequently, 13 mL of concentrated sulfuric acid was added to this mixed acid to prepare a reaction solution. To this solution, 7.5 g (31 mmol) of 2,5-dibromothiophene was slowly added dropwise while maintaining the reaction temperature between 20 and 30 °C by means of a water bath with continuous stirring for 3 hours. Upon completion of the reaction, the reaction solution was transferred to a vessel containing 90 g of ice to terminate the reaction. The resulting solid product was collected by filtration and purified by recrystallization with methanol to give the final target product 2,5-dibromo-3,4-dinitrothiophene. The yield based on 2,5-dibromothiophene was 66%.

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