反应 #1869164

反应方程式

2-Amino-5-bromopyridine

2,5-hexanedione

p-toluenesulfonic acid

→

5-Bromo-2-(2,5-dimethylpyrrol-1-yl)pyridine

收率 80.0%

溶剂

heptane

反应条件

后处理

1. 1
   温度refluxed under Dean Stark conditions overnight
2. 2
   workup.DISTILLATIONThe equipment was set for distillation and heptane (18 L)
3. 3
   其他was removed by distillation
4. 4
   workup.ADDITIONSeed crystals were added
5. 5
   其他at 5° C.
6. 6
   其他overnight
7. 7
   过滤The product was collected by filtration
8. 8
   洗涤washed with heptane (2×6 L)
9. 9
   其他dried at 45° C. under vacuum overnight

实验过程

2-Amino-5-bromopyridine (6.0 Kg, 34.7 mol), 2,5-hexanedione (4.35 Kg, 38.2 mol) and p-toluenesulfonic acid (12 g) were dissolved in heptane (36 L) and refluxed under Dean Stark conditions overnight. The equipment was set for distillation and heptane (18 L) was removed by distillation. The mixture was cooled to 20° C. for 60 minutes. Seed crystals were added and the mixture granulated at 20° C. for 2 hours and then at 5° C. overnight. The product was collected by filtration, washed with heptane (2×6 L) and dried at 45° C. under vacuum overnight. Yield=80% (7.0 Kg) δH (CDCl3 300 MHz) 2.20 (6H, s), 5.95 (2H, s), 7.15 (1H, d), 7.95 (1H, d), 8.70 (1H, s) ppm. MS m/z 253 (MH+, Br isotope).

来源