Synthesis
GENERAL STEPS: Acetic anhydride (0.44 mL, 4.7 mmol) was slowly added dropwise to a solution of dichloromethane (5.22 mL) containing aluminum chloride (896 mg, 6.7 mmol) at room temperature. After stirring the reaction mixture for 10 minutes, a solution of N-tosylpyrrole (400 mg, 1.81 mmol) in dichloromethane (0.9 mL) was added dropwise. Stirring of the reaction mixture was continued for 2 hours. Upon completion of the reaction, the mixture was poured into an ice-water mixture. The organic phase was separated and the aqueous phase was extracted with dichloromethane. The organic phases were combined, washed with 1N NaOH aqueous solution and dried over anhydrous sodium sulfate. After filtration, the solvent was evaporated to obtain the crude product. The crude product was washed with methanol and further purified to give 1-(1-toluenesulfonyl-1H-pyrrol-3-yl)ethanone (470 mg, 1.78 mmol, 99% yield) as a pure solid. Thin layer chromatography (TLC) analysis showed an Rf value of 0.5 (unfolding agent: hexane/ethyl acetate, 6/4). The structure of the product was confirmed by 1H NMR spectroscopy [24].
References
[1] Journal of Heterocyclic Chemistry, 2009, vol. 46, # 6, p. 1285 - 1295
[2] European Journal of Medicinal Chemistry, 2012, vol. 57, p. 391 - 397
[3] Patent: US2006/189555, 2006, A1. Location in patent: Page/Page column 10
[4] European Journal of Organic Chemistry, 2018, vol. 2018, # 1, p. 60 - 77
[5] Journal of Organic Chemistry, 1993, vol. 58, # 27, p. 7899 - 7902
