Synthesis
General procedure for the synthesis of 4-nitrochlorobenzaldehyde oxime from 4-nitrobenzaldoxime: 4-nitrobenzaldoxime (087 mg, 5.3 mmol) was dissolved in anhydrous dimethylformamide (4.6 mL) and the solution was cooled down to 0 °C. N-chlorosuccinimide (800 mg, 6.0 mmol) was added in batches with stirring. The cooling bath was removed and the resulting mixture was stirred at room temperature for 4 hours. After completion of the reaction, ice water (20 mL) was added and the resulting mixture was extracted with ether. The organic layer was washed three times with water, once with saturated brine and dried with anhydrous magnesium sulfate. The solvent was removed under reduced pressure after filtration to give a white solid 4-nitrochlorobenzaldehyde oxime (1.064 g, 100%).1H NMR (400 MHz, CDCl3) data were as follows: δ 8.37 (s, 1H, -OH), 8.27 (d, J = 8.8 Hz, 2H, Ar-H), 8.04 (d, J = 8.8 Hz, 2H, Ar-H).
References
[1] Patent: WO2011/15037, 2011, A1. Location in patent: Page/Page column 42; 53
[2] Patent: US2011/212975, 2011, A1. Location in patent: Page/Page column 14; 19
[3] Tetrahedron Letters, 2006, vol. 47, # 9, p. 1457 - 1460
[4] Journal of Chemical Research, 2007, # 1, p. 26 - 28
[5] Tetrahedron, 2000, vol. 56, # 8, p. 1057 - 1064
