Synthesis
The general procedure for the synthesis of O-(4-nitrophenyl)hydroxylamine from the compound (CAS: 83077-00-3) is as follows: wet ethyl N-(4-nitrophenoxy)acetimidate (781 g, dry wt.) was dissolved in 210 g of acetonitrile and the reaction temperature was adjusted to about 25 °C. Under the condition of keeping the reaction temperature below 30°C, 515 g of 37% hydrochloric acid was slowly added. The reaction mixture was stirred continuously at 25-30°C until the reaction was complete, which took about 2 hours. Subsequently, 209 g of 12% aqueous sodium hydroxide solution was slowly added to the reaction mixture at the same temperature range and stirring was continued for about 30 minutes. About 85% of the acetonitrile was removed by distillation at a jacket temperature of 50°C (internal temperature maintained at 25-30°C) under vacuum at 100 mbar. To the residue 20,900 g of water was added and the resulting slurry was stirred for 60 minutes. The product was collected by filtration, washed with 505 g of water and finally dried under vacuum at 40 °C. A final 560 g of O-(4-nitrophenyl)hydroxylamine was obtained in 94% yield.
References
[1] Patent: WO2010/38029, 2010, A1. Location in patent: Page/Page column 45
[2] Patent: WO2010/116140, 2010, A1. Location in patent: Page/Page column 47
[3] Patent: WO2009/44143, 2009, A2. Location in patent: Page/Page column 38
[4] Journal of Organic Chemistry, 1984, vol. 49, p. 1348 - 1352
[5] Journal of the American Chemical Society, 1982, vol. 104, # 23, p. 6393 - 6397
