反应 #465957

ord-acf0f52ede6d4866ab564428aa773da1

反应方程式

O=[N+]([O-])O
nitric acid
O=S(=O)(O)O
sulfuric acid
COC(=O)c1nc(Br)ccc1Cl
methyl 6-bromo-3-chloropyridine-2-carboxylate
COC(=O)c1nc(Br)cc([N+](=O)[O-])c1Cl
methyl 6-bromo-3-chloro-4-nitropyridine-2-carboxylate

反应条件

温度
70°CELSIUS
详细条件
See reaction.notes.procedure_details.

后处理

  1. 1
    萃取extracted with ethyl acetate (3×75 mL)
  2. 2
    干燥dried (Na2SO4)
  3. 3
    浓缩concentrated
  4. 4
    其他The dark oil was chromatographed over silica in 4:1 EtOAc/hexane

实验过程

To a solution of fuming nitric acid (10 mL) and fuming sulfuric acid (10 mL) was added methyl 6-bromo-3-chloropyridine-2-carboxylate, N-oxide and the reaction was heated to 70° C. in an oil bath for 4 hr. The mixture was poured over ice water (100 mL) and extracted with ethyl acetate (3×75 mL) and the combined extracts were backwashed with brine, dried (Na2SO4) and concentrated. The dark oil was chromatographed over silica in 4:1 EtOAc/hexane to give methyl 6-bromo-3-chloro-4-nitropyridine-2-carboxylate, N-oxide (0.007 mol, 2.2 g). 1H NMR (CDCl3): δ 4.1 (3H, s), 8.4 (1H, s).

来源

DOI: 10.6084/m9.figshare.5104873.v1专利: US06297197B1uspto-grants-2001_10