反应详情

To a colorless, homogeneous solution of (E)-benzaldehyde oxime (24.4 g, 201 mmol) in N,N-dimethylformamide (60 mL) at room temperature was added N-chlorosuccinimide (26.9 g, 201 mmol) portion-wise over 30 min. During each addition, the reaction mixture would turn yellow and then gradually return to near colorlessness. Additionally, an exotherm was noted with each portion added to ensure that the reaction initiated after the addition of N-chlorosuccinimide. An ice bath was available, if required, to cool the exotherm. After the addition was complete, the homogeneous reaction mixture was stirred overnight at room temperature. The reaction mixture was diluted with 250 mL of water and extracted with ether (3×100 mL). The organic layers were combined, washed with water (2×100 mL), washed with a 10% aqueous solution of lithium chloride (2×100 mL), and washed with brine (100 mL). The aqueous layers were back extracted with ether (100 mL), and the combined organic layers (400 mL) were dried over anhydrous sodium sulfate. Concentration under reduced pressure afforded (Z)-N-hydroxybenzimidoyl chloride (30.84 g, 198 mmol, 98% yield) as a fluffy, pale yellow solid. The product had an HPLC ret. time=1.57 min.−Column. CHROMOLITH® SpeedROD 4.6×50 mm (4 min.); Solvent A=10% MeOH, 90% H2O, 0.1% TFA; Solvent B=90% MeOH, 10% H2O, 0.1% TFA. LC/MS M+1=155.8. 1H NMR (500 MHz, DMSO-d6) δ ppm 7.30-7.64 (m, 3H), 7.73-7.87 (m, 2H), and 12.42 (s, 1H).

1. additionDuring each addition
2. additionadded
3. customAn ice bath was available
4. temperatureto cool the exotherm
5. additionAfter the addition
6. extractionextracted with ether (3×100 mL)
7. washwashed with water (2×100 mL)
8. washwashed with a 10% aqueous solution of lithium chloride (2×100 mL)
9. washwashed with brine (100 mL)
10. extractionThe aqueous layers were back extracted with ether (100 mL)
11. dry with materialthe combined organic layers (400 mL) were dried over anhydrous sodium sulfate
12. concentrationConcentration under reduced pressure