O-phthalate

Henkel Rearrangement of Benzoic Acid and Phthalic Anhydride. Henkel technology is based on the conversion of benzenecarboxyhc acids to their potassium salts. The salts are rearranged in the presence of carbon dioxide and a catalyst such as cadmium or zinc oxide to form dipotassium terephthalate, which is converted to terephthahc acid (59—61). Henkel technology is obsolete and is no longer practiced, but it was once commercialized by Teijin Hercules Chemical Co. and Kawasaki Kasei Chemicals Ltd. Both processes foUowed a route starting with oxidation of napthalene to phthahc anhydride. In the Teijin process, the phthaHc anhydride was converted sequentially to monopotassium and then dipotassium o-phthalate by aqueous recycle of monopotassium and dipotassium terephthalate (62). The dipotassium o-phthalate was recovered and isomerized in carbon dioxide at a pressure of 1000—5000 kPa ( 10 50 atm) and at 350—450°C. The product dipotassium terephthalate was dissolved in water and recycled as noted above. Production of monopotassium o-phthalate released terephthahc acid, which was filtered, dried, and stored (63,64). 

Developments in the USA have led to the availability of terephthalate plasticisers, for example dioctyl terephthalate (DOTP). Whilst these materials are very similar to the corresponding o-phthalate esters they are generally less volatile and are best compared with d-phthalates with one or more carbon atom in the alkyl chain. As with the linear dialkyl phthalates the terephthalates show good fogging resistance. This is a phenomenon in which new cars on storage fields awaiting delivery develop misting on the windows due, apparently, to the volatility of additives in PVC compounds used with the car. 

Lipophilic N-tetrabenzylcylam, III, at pH 4-7 was found to be a good carrier for liquid membrane transport of dicarboxylate anions, such as o-phthalate, and of amino acid anions52). It was suggested that the diprotonated species, H2L2+, is an active carrier species for anions. 

Diallyl o-phthalate Good electrical insulation, low water absorption Compression molding... 

Unsaturated Maleate/O-Phthalate/1,2-Propanediol Polyester Prepolymer... 

Notes (a) Cobalt(II) 2-ethylhexanoate, 65% mass solution in mineral spirits (b) 2-butanone peroxide, ca. 32% mass solution in dimethyl o-phthalate. 

Ultralow-monol polyols, 223 Ultrapek, 327, 328 Ultraviolet (UV) radiation, 209 Ultraviolet spectroscopy, 490 Unimolecular micelle, 58 United States, phenolic production in, 375 Unsaturated maleate/O-phthalate/ 1,2-propanediol polyester prepolymer, 101-102 Unsaturated polyester resins (UPRs), 19, 29-30, 58-59... 

Kiyohara H, K Nagao, R Nomi (1976) Degradation of phenanthrene through o-phthalate by an Aeromonas sp. Agric Biol Chem 40 1075-1082. 

The degradation of benzoate (Taylor and Heeb 1972 Williams and Evans 1975 Ziegler et al. 1987) and o-phthalate (Nozawa and Maruyama 1988 Afring and Taylor 1981). 

The degradation of isoquinoline by Alcaligenes faecalis strain Pa and Pseudomonas diminuta strain 7 (Roger et al. 1990, 1995) is mediated by an oxidoreductase that produces 1,2-dihydroiso-quinoline-l-one, followed by ring fission with the production of o-phthalate and oxidation to 3,4-dihydroxybenzoate (Figure 3.38). The oxidoreductase is purified and like most typical aza-rene oxidoreductases contains, per mole, 0.85 g atoms of Mo, 3.9 g atoms of Fe, and acid-labile S (Lehmann et al. 1994). 

Althongh the degradation of naphthalene-2-carboxylate by Burkholderia sp. strain JT 1500 involves the formation of 1-hydroxy naphthalene-2-carboxylate, this is not formed from the expected (l/ ,25)-di-l,2-dihydrodiol-2-naphthoate. Possibly, therefore, the reaction is carried out by a monooxygenase, or a dehydration step is involved. Subsequent reactions produced pyruvate and o-phthalate that was degraded via 4,5-dihydroxyphthalate (Morawski et al. 1997). Degradation of naphthalene carboxylates formed by oxidation of methyl groups has already been noted. 

The degradation of these was described many years ago (Evans et al. 1965), and details have since been added (Figure 8.10a) (van Herwijnen et al. 2003). Phenanthrene is more readily degraded than anthracene, and both can be degraded to o-phthalate. After hssion of the peripheral ring in phenanthrene, several pathways have been demonstrated ... 

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