Reacción #2006478

Ecuación de reacción

Toluene

NaOH

5-amino-2-cyanobenzotrifluoride

phosgene

toluene

→

compound 8a

4-Isocyanato-2-trifluoromethyl-benzonitrile

Disolventes

ethyl acetate

ethyl acetate

Condiciones de reacción

Tratamiento posterior

1. 1
   Otroto return at room temperature
2. 2
   Temperaturathe resulting solution was refluxed for 3 hrs
3. 3
   OtroThe first 6 mL of distilled solvent was removed
4. 4
   FiltraciónThe solution was then filtrated
5. 5
   Otroevaporated

Procedimiento

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.

Fuente