Reacción #1869164

Ecuación de reacción

2-Amino-5-bromopyridine

2,5-hexanedione

p-toluenesulfonic acid

→

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

Rendimiento 80.0%

Disolventes

heptane

Condiciones de reacción

Tratamiento posterior

1. 1
   Temperaturarefluxed under Dean Stark conditions overnight
2. 2
   workup.DISTILLATIONThe equipment was set for distillation and heptane (18 L)
3. 3
   Otrowas removed by distillation
4. 4
   workup.ADDITIONSeed crystals were added
5. 5
   Otroat 5° C.
6. 6
   Otroovernight
7. 7
   FiltraciónThe product was collected by filtration
8. 8
   Lavadowashed with heptane (2×6 L)
9. 9
   Otrodried at 45° C. under vacuum overnight

Procedimiento

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).

Fuente