16689-02-4

6030-18-8

16689-02-4

General procedure for the synthesis of 5-nitrothiophene-2-carbonitrile from the compound (CAS: 6030-18-8): oxime (1.0 mmol) and 2-nitrobenzenesulfonate (1.5 mmol) were dissolved in anhydrous dichloromethane (5.0 mL) under nitrogen protection in an oven-drying 50 mL round-bottomed flask fitted with a stirrer. The reaction mixture was stirred at room temperature for 5 min and then 1,8-diazabicycloundec-7-ene (DBU, 2.5 mmol) was slowly added dropwise over 2 min. Upon completion of the dropwise addition, the reaction mixture changed to a clarified homogeneous solution. The reaction process was monitored by thin layer chromatography (TLC). After complete consumption of the starting material, the reaction mixture was diluted with ethyl acetate and washed sequentially with water (2 × 5 mL) and brine (2 × 5 mL). The product was purified by column chromatography. The by-product Oxyma can be recovered by acidifying the aqueous layer followed by extraction with ethyl acetate. The recovered Oxyma can be used to regenerate Oxyma sulfonate, which in turn can be used in another batch reaction.