تفاعل #1869164

معادلة التفاعل

2-Amino-5-bromopyridine

2,5-hexanedione

p-toluenesulfonic acid

→

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

المردود 80.0%

المذيبات

heptane

ظروف التفاعل

المعالجة

1. 1
   درجة الحرارةrefluxed under Dean Stark conditions overnight
2. 2
   workup.DISTILLATIONThe equipment was set for distillation and heptane (18 L)
3. 3
   أخرىwas removed by distillation
4. 4
   workup.ADDITIONSeed crystals were added
5. 5
   أخرىat 5° C.
6. 6
   أخرىovernight
7. 7
   ترشيحThe product was collected by filtration
8. 8
   غسيلwashed with heptane (2×6 L)
9. 9
   أخرىdried at 45° C. under vacuum overnight

الإجراء التجريبي

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).

المصدر