4,4'-Difluorobenzophenone → Phthalonitrile

Temperature

160 °C

To a 100 ml, 3-necked flask equipped with a thermometer and a Dean-Stark trap was added 4.0 gm (18.4 mmol) of 4,4'-difluorobenzophenone, 12.33 gm (36.7 mmol) of bisphenol A6F, and 40 ml of dimethylacetamide (DMAC). After flushing the mixture for 30 minutes with dry nitrogen, 10.1 gm (73.4 mmol) of pulverized anhydrous potassium carbonate was added with stirring. The light pink reaction mixture was stirred at 90° C. for 1 hour. Toluene was added to the Dean-Stark trap and to the reaction vessel (4 ml). The reaction mixture was refluxed at 145°-150° C. for 26 hours. Water which formed as a by-product was removed by azeotropic distillation. The toluene was-removed by distillation while heating to 160° C. Upon cooling to 50° C., 6.37 gm (36.8 mmol) of 4-nitrophthalonitrile was added. The reaction mixture was observed to be viscous. The temperature of reaction mixture was increased to 110° C. and held at this temperature for 16 hours (overnight). The room temperature mixture was poured into 200 ml of water with stirring. The solid precipitate was collected by suction filtration, washed exhaustively with water, and dried to afford 20.1 gm of oligomeric phthalonitrile monomer.

1. customTo a 100 ml, 3-necked flask equipped with a thermometer
2. additionwas added
3. stirringThe light pink reaction mixture was stirred at 90° C. for 1 hour
4. temperatureThe reaction mixture was refluxed at 145°-150° C. for 26 hours
5. customwas removed by azeotropic distillation
6. customThe toluene was-removed by distillation
7. temperatureUpon cooling to 50° C.
8. customThe temperature of reaction mixture
9. temperaturewas increased to 110° C.
10. custom(overnight)
11. stirringwith stirring
12. filtrationThe solid precipitate was collected by suction filtration
13. washwashed exhaustively with water
14. customdried

ORD record

ord-9d35db3b522947699667f4defbb2bdde

Source dataset

uspto-grants-1995_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05464926