Preparation method of 2-(4-aminobenzene)-1,1,1,3,3,3-hexafluoro-2-propanol_Industrial additives

Background and overview^[1]

2-(4-Aminobenzene)-1,1,1,3,3,3-hexafluoro-2-propanol can be used to prepare bisphenol AF. Bisphenol AF (hexafluorobisphenol A: 2,2-bis-(4-hydroxyphenyl)hexafluoropropane) is mainly used as a fluorine rubber vulcanization accelerator. In view of the advantages of bisphenol AF vulcanized fluororubber with good shaping effect, high thermal stability, excellent tensile strength and resistance to degeneration, bisphenol AF is indispensable in the field of fluororubber preparation.

Preparation^[1]

In a four-necked flask, add 0.02 mol of p-toluenesulfonic acid to 0.1 mol of aniline under stirring, replace it with N2 gas, and slowly add 0.3 mol HFA·3H2O under heating (complete the addition in about 30 minutes). After the addition is completed, continue to reflux at 110°C for 8 hours, stop the reaction, and cool to room temperature to form a white solid. Add diethyl ether to dissolve, filter and wash. The filtrate is rotary evaporated to remove diethyl ether and other low boiling point substances, and after drying, crude product 2-(4-aminobenzene)-1,1,1,3,3,3-hexafluoro-2-propanol is obtained, with a yield of 90.2%. (GC-MS), the purity reached 97.9%.

Apply^[1]

Under magnetic stirring, add 0.3 mol of methane sulfonic acid to the three-necked flask, and add 0.08 mol of phenol and 0.02 mol of compound (2) under N2 gas protection at room temperature. The reaction was stirred at 160°C for 8 hours. Wash with water three times, then extract with an appropriate amount of a mixture of dichloromethane and diethyl ether (1:1), and combine the organic phases. The aqueous phase is dehydrated under reduced pressure to obtain slightly yellow methane sulfonic acid, which can be reused. The solvent and unreacted phenol were removed from the organic phase, dried and recrystallized to obtain the light brown target product bisphenol AF (3), with a yield of 72.4%.

References

[1] [China invention, China invention authorization] CN200810243703.1 Preparation method of bisphenol AF