4,4'-Dihydroxybiphenyl → Phthalonitrile

Temperature

160 °C

To a 100 ml, 3-necked flask equipped with a thermometer and a Dean-Stark trap was added 3.52 gm (16.1 mmol) of 4,4'-difluorobenzophenone, 4.0 gm (21.5 mmol) of 4,4'-dihydroxybiphenyl, and 40 ml of dimethylacetamide (DMAC). After flushing the mixture for 30 minutes with dry nitrogen, 5.0 gm (36.2 mmol) of pulverized anhydrous potassium carbonate was added with stirring. The reaction content 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 10 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 ambient condition, 1.86 gm (10.7 mmol) of 4-nitrophthalonitrile was added. The reaction mixture turned purple. The reaction content was then stirred at the ambient temperature for 2 hours and at 90° C. for 6 hours. The reaction was monitored by FTIR spectroscopy and showed the complete disappearance of the absorptions attributed to the nitro and hydroxyl groups. 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 7.8 gm of oligomeric phthalonitrile monomer.

1. customTo a 100 ml, 3-necked flask equipped with a thermometer
2. additionwas added
3. stirringThe reaction content was stirred at 90° C. for 1 hour
4. temperatureThe reaction mixture was refluxed at 145°-150° C. for 10 hours
5. customwas removed by azeotropic distillation
6. customThe toluene was removed by distillation
7. additionwas added
8. stirringThe reaction content was then stirred at the ambient temperature for 2 hours and at 90° C. for 6 hours
9. stirringwith stirring
10. filtrationThe solid precipitate was collected by suction filtration
11. washwashed exhaustively with water
12. customdried

ORD record

ord-d84f2bc38f31467d826cb0dc0d432224

Source dataset

uspto-grants-1995_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05464926