Reaktion #337463

Reaktionsgleichung

HCl

6-bromo-benzo[b]-thiophene-2-carboxylic acid

→

title compound

Ausbeute 62.7%

6-Bromo-benzo[b]thiophene

Ausbeute 62.7%

Lösungsmittel

quinoline

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturThe reaction mixture is heated
2. 2
   TemperaturThe reaction mixture is cooled to room temperature
3. 3
   workup.ADDITIONpoured onto ice (2.5 Kg)
4. 4
   ExtraktionThe reaction mixture is extracted with hexane (4×3 L)
5. 5
   Waschenwashed with dilute HCl (1×2 L), aqueous bicarbonate (1×5 L), and brine solution (1×5 L)
6. 6
   SonstigeThe layers are separated
7. 7
   Trocknenthe organic layer is dried over sodium sulfate
8. 8
   Einengenconcentrated

Vorschrift

Copper powder (100 g, 1.57 mol) is added to a solution of 6-bromo-benzo[b]-thiophene-2-carboxylic acid (1.04 Kg, 4.04 mol) in quinoline (2.5 L) at room temperature. The reaction mixture is heated to reflux (195° C.) for 10 h. The reaction mixture is cooled to room temperature and poured onto ice (2.5 Kg). Concentrated HCl (2.5 L) is added while stirring the resulting mass for 1 h. The reaction mixture is extracted with hexane (4×3 L) and washed with dilute HCl (1×2 L), aqueous bicarbonate (1×5 L), and brine solution (1×5 L). The layers are separated and the organic layer is dried over sodium sulfate and concentrated to give the title compound (0.54 Kg, 62%) as a light yellow solid.

Quelle