Reaktion #354652

Reaktionsgleichung

1,2-dichloro-2,2-difluoro-1-(trifluoromethyl)ethyl isocyanate

→

2,2-difluoro-1-(trifluoromethyl)vinyl isocyanate

Ausbeute 91.3%

Lösungsmittel

glycol dimethyl ether

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturwarmed to 45°
2. 2
   Sonstigeremained between 45°-50°
3. 3
   workup.ADDITIONafter the addition
4. 4
   workup.DISTILLATIONthe most volatile portion was distilled under reduced pressure (5 mm) into a trap
5. 5
   Temperaturcooled to -78°
6. 6
   workup.DISTILLATIONThe condensate in the trap was redistilled

Vorschrift

A 244 g sample (1.0 mole) of 1,2-dichloro-2,2-difluoro-1-(trifluoromethyl)ethyl isocyanate was added dropwise to a stirred suspension of 98 g (1.5 gram atom) of powdered zinc in 1000 ml of glycol dimethyl ether at such a rate that the temperature warmed to 45° and remained between 45°-50°. The reaction mixture was stirred for 1 hr after the addition, and then the most volatile portion was distilled under reduced pressure (5 mm) into a trap cooled to -78°. The condensate in the trap was redistilled to give 158 g (91%) of 2,2-difluoro-1-(trifluoromethyl)vinyl isocyanate as a colorless liquid: bp 42.3°-42.5°, ir (liquid), 4.38 μ (NCO) and 5.67 μ (=CF2); 19F nmr (CCl3F) δ 66.6 ppm (d, J = 9 Hz to d, J = 23 Hz, 3F) δ 82.9 ppm (d, J = 21 Hz to q, J = 9 Hz, IF) and δ 89.7 ppm (d, J = 21 Hz to d, J = 23 Hz, IF).

Quelle