Synthesis
The general procedure for the synthesis of N-benzylhydroxylamine hydrochloride from the compound (CAS:3376-26-9) was as follows: in a two-necked round-bottomed flask equipped with a stirrer, a mixture of dibenzylamine (1) (32.8 g, 0.17 mol), Na2WO4-2H2O (0.98 g, 3.33 mmol) and methanol (0.17 L) was cooled to -15 °C. A 30% aqueous solution of H2O2 (57 mL, 0.5 mol) was slowly added dropwise over about 1 h via a pressure equalizing dropping funnel. After the dropwise addition, the reaction mixture was stirred continuously at room temperature for 16 hours. Subsequently, the mixture was transferred to a 3 L beaker and crushed ice (1 kg) was added under vigorous stirring. The white precipitate formed was collected by filtration and washed several times with ice water (1 L) to completely remove the peroxide. The wet crude nitrone was dissolved in 20% aqueous HCl solution (0.33 L) and concentrated under reduced pressure at a water bath temperature of 70 °C. To remove trace water, the mixture was washed with toluene (3 x 33 mL) and subsequently concentrated under vacuum to dryness overnight. Finally, recrystallization was carried out using minimal amounts of hot methanol (30 mL) and ether (115 mL) to give a white crystalline pure product (19.3 g, 71% yield). The 1H and 13C NMR spectra of the product were in agreement with those reported in the literature; ESI-HRMS analysis resulted in a calculated value of 124.07 and a measured value of 124.0750 for C7H9NO(M + H)+.
References
[1] Synthetic Communications, 2005, vol. 35, # 18, p. 2445 - 2451
[2] Synthetic Communications, 2005, vol. 35, # 18, p. 2445 - 2451
[3] Journal of Organic Chemistry, 1983, vol. 48, # 9, p. 1444 - 1448
[4] Synthesis, 2009, # 18, p. 3174 - 3176
[5] Bioorganic and Medicinal Chemistry Letters, 2011, vol. 21, # 17, p. 4969 - 4972
