GENERAL STEPS: To a dry 500 mL four-necked round-bottomed flask were added dimethyl sulfoxide (DMSO, 100 mL), 3-aminophenol (67.5 g) and sodium hydroxide (NaOH, 24.7 g). The reaction mixture was heated to 75-80 °C and maintained at this temperature for 4 hours. Subsequently, 4-nitrophenyl-N,N-dimethylcarbamate (100 g) and DMSO (100 mL) were added in batches at the same temperature. The reaction temperature was raised to 110-120 °C and the reaction was continued for 2 hours. The progress of the reaction was monitored by thin layer chromatography (TLC). Upon completion of the reaction, the reaction was quenched with 1% sodium hydroxide solution (1500 mL). Extraction was carried out with methylene chloride (MDC), the organic layer was separated, washed with water, dried over anhydrous sodium sulfate and concentrated under reduced pressure to give the crude product. The crude product was recrystallized with toluene to obtain pure 3-aminophenyl dimethylcarbamate. Yield: 62 g (72.2% yield). Melting point: 83-85°C (literature value: 80-86°C, FR 1498834).
