Реакция #1869164

Уравнение реакции

2-Amino-5-bromopyridine

2,5-hexanedione

p-toluenesulfonic acid

→

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

Выход 80.0%

Растворители

heptane

Условия реакции

Обработка

1. 1
   Температураrefluxed under Dean Stark conditions overnight
2. 2
   workup.DISTILLATIONThe equipment was set for distillation and heptane (18 L)
3. 3
   Другоеwas removed by distillation
4. 4
   workup.ADDITIONSeed crystals were added
5. 5
   Другоеat 5° C.
6. 6
   Другоеovernight
7. 7
   ФильтрацияThe product was collected by filtration
8. 8
   Промывкаwashed with heptane (2×6 L)
9. 9
   Другоеdried at 45° C. under vacuum overnight

Методика

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).

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