反应详情

To an ice cold (0-5° C.) solution of dry dimethylformamide (6.67 mL, 86.5 mmol) was added phosphorous oxychloride (7.66 mL, 81.6 mmol) dropwise with stirring for 15 min. To this cold mixture, cyclohexanone (5 g, 51 mmol) was added dropwise maintaining the temperature of the reaction mixture below 40° C. for 1 h. Hydroxylamine hydrochloride (20 g, 288 mmol) was added portion wise for 20 min. The addition of hydroxylamine hydrochloride was maintained at such a rate that the temperature of the reaction mixture rise above 145-155° C. After completion of the addition, the reaction mixture was allowed to room temperature (rt) for 30 min, diluted with cold water (0.5 L) and stirred for 30 min. The precipitated solid was filtered, washed with cold water and dried to give the product as a brown color solid (2.8 g, 39%), mp 38-40° C. 1H NMR (400 MHz, CDCl3): δ 2.45-2.50 (2H, m, H-6), 2.33-2.37 (2H, m, H-3), 1.75-1.81 (2H, m, H-5), 1.66-1.72 (2H, m, H-4).

1. temperaturemaintaining the temperature of the reaction mixture below 40° C. for 1 h
2. temperaturewas maintained at such a rate that the temperature of the reaction mixture
3. customrise above 145-155° C
4. additionAfter completion of the addition
5. customwas allowed to room temperature
6. custom(rt)
7. customfor 30 min
8. stirringstirred for 30 min
9. filtrationThe precipitated solid was filtered
10. washwashed with cold water
11. customdried