Réaction #4445

Équation de réaction

α-bromo-4-acetylpyridine hydrobromide

potassium thiocyanate

hydrochloric acid

water

→

2-hydroxy-4-(4-pyridyl)thiazole

Solvants

ethanol

Conditions de réaction

Traitement

1. 1
   Températurewas heated
2. 2
   Températureto reflux for two hours
3. 3
   Températurereflux
4. 4
   TempératureAfter cooling
5. 5
   Filtrationthe crystallized solid was collected by filtration
6. 6
   Lavagewashed with ethanol
7. 7
   Autreto obtain
8. 8
   Filtrationafter filtration
9. 9
   Autredrying

Mode opératoire

A mixture of α-bromo-4-acetylpyridine hydrobromide (140.0 g, 0.50 mol) and potassium thiocyanate (53.4 g, 0.55 mol) in absolute ethanol (1500 mL) was heated to reflux for two hours. To the resulting mixture was added concentrated hydrochloric acid (250 mL) and water (500 mL) and reflux continued for five hours. After cooling, the crystallized solid was collected by filtration and washed with ethanol. The resulting material was suspended in water and neutralized with aqueous sodium bicarbonate to obtain, after filtration and drying, 2-hydroxy-4-(4-pyridyl)thiazole 39.0 g, 44%). mp. 250° C.

Source