Reaktion #422547

Reaktionsgleichung

4-bromobenzene-1,2-diamine

Hunig's base

SOCl2

→

5-bromobenzo[1,2,5]thiadiazole

Lösungsmittel

dichloromethane

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeThe resulting reaction mixture
2. 2
   Temperaturwas heated
3. 3
   Temperaturto reflux overnight
4. 4
   Sonstigequenched with 10% HCl until pH=2
5. 5
   ExtraktionThe resulting mixture was extracted with dichloromethane (200 mL×4)
6. 6
   Trocknendried over Na2SO4
7. 7
   Einengenconcentrated
8. 8
   SonstigeThe crude compound was purified by flash column chromatography (silica gel, chloroform)

Vorschrift

To a solution of 4-bromobenzene-1,2-diamine (5.236 g, 28.0 mmol) and Hunig's base (19.5 mL, 112 mmol) in dichloromethane (160 mL) was added SOCl2 (4.08 mL, 56 mmol) dropwise at room temperature. The resulting reaction mixture was heated to reflux overnight. The reaction mixture was then allowed to cool to room temperature, and quenched with 10% HCl until pH=2. The resulting mixture was extracted with dichloromethane (200 mL×4), dried over Na2SO4 and concentrated. The crude compound was purified by flash column chromatography (silica gel, chloroform) to afford 5-bromobenzo[1,2,5]thiadiazole as a brown solid which was used directly in the next step. 1H NMR (CDCl3 500 MHz): δ: 8.21 (d, 1H, J=1.5 Hz), 7.87 (d, 1H, J=8.5 Hz), 7.69 (dd, 1H, J=8.5, 1.5 Hz).

Quelle