3,3'-Bis(1-hydroxy-1-trifluoromethyl-2,2,2-trifluoroethyl)-4,4'-oxydianiline → 4,4'-Diaminodiphenyl Ether

The reaction liquid was found by gas chromatography (GC) analysis to contain 60.1% of the target compound, 3,3′-bis(1-hydroxy-1-trifluoromethyl-2,2,2-trifluoroethyl)-4,4′-oxydianiline, 25.0% of 3-(1-hydroxy-1-trifluoromethyl-2,2,2-trifluoroethyl)-4,4′-oxydianiline, and 14.4% of the total of various imines produced by the reaction of hexafluoroacetone with the amine moiety of 4,4′-oxydianiline. 100 ml of water were added to the reaction liquid, followed by extraction with 100 ml of ethyl acetate. Then, the organic layer was washed with 50 ml of saturated sodium hydrogencarbonate aqueous solution. The organic layer was dried with magnesium sulfate, followed by filtration and distilling the solvent off, thereby obtaining 112 g of crude 3,3′-bis(1-hydroxy-1-trifluoromethyl-2,2,2-trifluoroethyl)-4,4′-oxydianiline (purity: 50.7%). This crude product was recrystallized in toluene, thereby obtaining 41.0 g of the target 3,3′-bis(1-hydroxy-1-trifluoromethyl-2,2,2-trifluoroethyl)-4,4′-oxydianiline (yield: 62%; purity: 95.7%).