Reaktion #2006478

Reaktionsgleichung

Toluene

NaOH

5-amino-2-cyanobenzotrifluoride

phosgene

toluene

→

compound 8a

4-Isocyanato-2-trifluoromethyl-benzonitrile

Lösungsmittel

ethyl acetate

ethyl acetate

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigeto return at room temperature
2. 2
   Temperaturthe resulting solution was refluxed for 3 hrs
3. 3
   SonstigeThe first 6 mL of distilled solvent was removed
4. 4
   FiltrationThe solution was then filtrated
5. 5
   Sonstigeevaporated

Vorschrift

To a solution of 5-amino-2-cyanobenzotrifluoride (1a) (2.0 g, 10.7 mmol) in ethyl acetate (6 mL) at 0° C. under argon, was added dropwise a 2.0 M solution of phosgene in toluene (6.5 mL, 12.9 mmol). The solution was stirred 30 min at 0° C. and allowed to return at room temperature. Toluene (3 mL) was then added to the ethyl acetate and the resulting solution was refluxed for 3 hrs using a Dean-Stark apparatus, equipped with an HCl trap (solid NaOH). The first 6 mL of distilled solvent was removed and replaced by toluene (6 mL). The solution was then filtrated and evaporated to give compound 8a (1.6 g) as an orange oil which was directly used for the next step. IR: 2268 (strong), 2232 (weak) cm−1.

Quelle