Claims
- 1. A process for conversion of bisphenols to dianilines comprising the steps of:
- a. forming the reaction product of an anhydrous bis-phenol and a halogenated phenyl-quinazoline by heating said compounds in the presence of a crown ether catalyst, a strong base, and a high-boiling polar solvent;
- b. subjecting said product to a thermal rearrangement by heating it in an inert atmosphere to thereby form a bis-quinazolinone; and
- c. hydrolyzing said bis-quinazolinone by refluxing it in the presence of a strong base in an alcoholic solvent, thereby forming a dianiline.
- 2. The process of claim 1 wherein said bis-phenol is a bis-phenol selected from the group whose formula is: ##STR4## where X is a single bond, S, O, SO.sub.2, CO, or C(CF.sub.n H.sub.3-n) where n is 0, 1 or 2.
- 3. A process in accordance with claim 1 wherein said halogenated phenylquinazoline is a compound whose structure is ##STR5## where X is Cl, Br or I.
- 4. The process of claim 1 or of claim 2 wherein said bis-phenol and said phenylquinazoline is heated in the presence of an 18-Crown-6 catalyst and potassium hydroxide.
- 5. The process of claim 2 wherein X in said bis-phenol contains a hexafluoroisopropylidene substituent.
- 6. An improved process for synthesizing 2,2-bis-(4-aminophenyl)hexafluoropropane comprising the steps of:
- heating a solution of 2,2-bis(4-hydroxyphenyl)hexafluoropropane with 4-chloro-2-phenylquinazoline in the presence of a catalytic mixture formed from a crown ether catalyst and a strong base in a high-boiling polar solvent, thereby causing a nucleophilic displacement reaction to occur which yields a bisquinazoline;
- heating said bis-quinazoline under an inert atmospheric purge thereby causing a thermal rearrangement to occur yielding a bisquinazolinone; and
- subsequently hydrolyzing said bisquinazoline by refluxing it in an alcoholic solvent with a strong base to form said bis(aminophenyl)hexafluoropropane which may be subsequently extracted from said alcoholic solvent and purified to a crystalline solid.
- 7. The process of claim 6 wherein said catalytic mixture is formed from an 18-Crown-6 catalyst and potassium hydroxide and wherein said polar solvent is dimethylsulfoxide.
- 8. The process of claim 6 wherein said bisquinazoline is heated at 320.degree..+-.5.degree. C. for at least 15 hours.
Government Interests
The Government has rights in this invention pursuant to Contract No. F33615-78-C-5197 awarded by the Department of the Air Force.
US Referenced Citations (2)
Number |
Name |
Date |
Kind |
3418371 |
Krimm et al. |
Dec 1968 |
|
4177211 |
Sun |
Dec 1979 |
|