4,4 -Oxydibenzoic acid

Bis[tetrafluoro-4-(trifluoromethyl)phenyl] ether on heating with 20% oleum gives octafluoro-4,4 -oxydibenzoic acid (3).163... 

Random copolyamides are also obtained from MDI or TDI with mixtures of isophthalic acid and 4,4 -oxydibenzoic acid. ° Multiblock copolymers are also obtained by reacting a mixture of isophthalic acid and azelaic acid with MDI to form a prepolymer, which is subsequently reacted with a, ty-bis(10-carboxy-decyl)polydimethylsiloxane. ... 

Copolymers from /y,/y-di(4-carboxyphenyl)-l-aminopyrene and 4,4 -oxydibenzoic acid show a significantly increased fluorescence quantum efficiency. In addition, the polymers have ambipolar electrochemical and electrochromic properties [60]. 

Ueda et al. established a modified method for the synthesis of PBOs (Figure 5.25) from 4,4 -oxydibenzoic acid and 3,3 -dihydroxybenzidine-dihydrochloride by using phosphorus pentoxide/ methanesulfonic acid (PPMA) as the condensing agent in place of PPA [54]. 

A suspension of 30 g of sodium hydride in benzene (30 ml) was added dropwise to 52 g of 8-chlorodibenzo[b,f]thiepin-10(llH)-one dissolved in dimethylformamide (800 ml), and the mixture was heated at 100°C for 2 hours. To this, there were added 68 g of 2-dimethylaminoethyl chloride, and the mixture was heated at 60°C for 39 hours. The reaction mixture, after cooled, was poured into ice-water, and the solution was extracted with ethyl acetate. The ethyl acetate layer, after washed with water, was extracted with 10% hydrochloric acid, when oil was precipitated. The aqueous layer, in which oil was precipitated, was washed with ether, made neutral with concentrated sodium hydroxide solution and then extracted with ethyl acetate. The ethyl acetate layer was washed with water, dried over magnesium sulfate, and concentrated to give oil, which was allowed to stand to provide solid. The solid was washed with petroleum ether and recrystallized from cyclohexane to yield 42.5 g of 8-chloro-10-(2-dimethylaminoethyl)-oxydibenzo[b,f]thiepin as crystals, melting point 90°C to 91°C. Maleate as colorless needle, melting point 204°C to 204.5°C. 

---