Реакция #4249

Уравнение реакции

Phosgene

methyl 2-(aminosulfonyl)-4-ethoxybenzoate

n-butyl isocyanate

→

methyl 4-ethoxy-2-(isocyanatosulfonyl)benzoate

Выход 98.4%

Растворители

Условия реакции

Обработка

1. 1
   Температураat reflux for 10 minutes
2. 2
   Другоеstayed at 133° C. or above
3. 3
   ДругоеWhen consumption of phosgene
4. 4
   Фильтрацияfiltered under nitrogen
5. 5
   ДругоеRotary evaporation

Методика

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.

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