Reaktion #4249

Reaktionsgleichung

Phosgene

methyl 2-(aminosulfonyl)-4-ethoxybenzoate

n-butyl isocyanate

→

methyl 4-ethoxy-2-(isocyanatosulfonyl)benzoate

Ausbeute 98.4%

Lösungsmittel

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturat reflux for 10 minutes
2. 2
   Sonstigestayed at 133° C. or above
3. 3
   SonstigeWhen consumption of phosgene
4. 4
   Filtrationfiltered under nitrogen
5. 5
   SonstigeRotary evaporation

Vorschrift

A solution of methyl 2-(aminosulfonyl)-4-ethoxybenzoate (7.56 g, 29.2 mmol), n-butyl isocyanate (3.29 mL, 29.2 mmol), and 1,4-diaza[2.2.2]bicyclooctane (0.13 g, 1.2 mmol) in mixed xylenes was heated at reflux for 10 minutes. Phosgene was then added at such a rate that the internal temperature stayed at 133° C. or above. When consumption of phosgene ceased, the solution was cooled to room temperature and then filtered under nitrogen. Rotary evaporation gave methyl 4-ethoxy-2-(isocyanatosulfonyl)benzoate as a cloudy yellow oil (8.2 g). This was used immediately without further purification or characterization.

Quelle