反应 #465958

反应方程式

H2O NH4OH

lithium aluminum hydride

methyl 6-bromo-3-chloro-4-nitropyridine-2-carboxylate

→

methyl 4-amino-6-bromo-3-chloropyridine-2-carboxylate

溶剂

tetrahydrofuran

THF

反应条件

后处理

1. 1
   workup.STIRRINGThe solution was stirred 1 hr
2. 2
   过滤filtering
3. 3
   萃取The filtrate was extracted with EtOAc (2×75 mL)
4. 4
   干燥The organic phase was dried (Na2SO4)
5. 5
   浓缩concentrated
6. 6
   其他The red solid was chromatographed over silica in 4:1 EtOAc/hexane

实验过程

To a solution of titanium tetrachloride (0.015 mol, 2.8 g) in tetrahydrofuran (50 mL) was added lithium aluminum hydride (0.0175 mol, 0.7 g). The black slurry was stirred 15 min before adding methyl 6-bromo-3-chloro-4-nitropyridine-2-carboxylate, N-oxide (0.007 mol, 2.3 g) in THF (25 mL). The solution was stirred 1 hr before pouring into 1:1 H2O/NH4OH and filtering. The filtrate was extracted with EtOAc (2×75 mL). The organic phase was dried (Na2SO4), and concentrated. The red solid was chromatographed over silica in 4:1 EtOAc/hexane to give methyl 4-amino-6-bromo-3-chloropyridine-2-carboxylate (0.003 mol, 0.8 g); mp 194-5° C. 1H NMR(CDCl3): δ 3.95 (3H, s), 5.3 (2H, bs), 6.9 (1H, s).

来源