Synthesis
Step 2. Synthesis of N-methyl-2-nitrobenzenesulfonamide
2-Nitrobenzene-1-sulfonyl chloride (4 g, 18.05 mmol) was dissolved in dichloromethane (DCM, 60.2 mL) and cooled to 0 °C in an ice water bath. Subsequently, triethylamine (TEA, 7.55 mL, 54.1 mmol) and tetrahydrofuran solution of 2M methylamine (13.54 mL, 27.1 mmol) were added sequentially to this solution. The reaction mixture was stirred at room temperature for 6 hours. After completion of the reaction, the reaction mixture was diluted with dichloromethane and washed with saturated aqueous sodium bicarbonate (NaHCO3) solution (2 x 100 mL) followed by brine (100 mL). The organic layer was dried with anhydrous magnesium sulfate, filtered and concentrated under reduced pressure. Finally, the concentrate was ground in ether to give N-methyl-2-nitrobenzenesulfonamide (3.12 g, 14.44 mmol, 80% yield). The product was analyzed by liquid chromatography-mass spectrometry (LCMS), showing a m/z of 217.1 (MH+) and a retention time of 0.53 min.
References
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[2] Patent: WO2012/92880, 2012, A1. Location in patent: Page/Page column 63-64
[3] Angewandte Chemie - International Edition, 2010, vol. 49, # 29, p. 4955 - 4957
[4] Chemical Communications, 2014, vol. 50, # 62, p. 8586 - 8589
[5] Patent: US9242996, 2016, B2. Location in patent: Page/Page column 255; 256
