5-Nitro isophthalic acid

Benzenedicarboxylic acid, 5-nitro- EINECS 210-568-3 Isophthalic acid, 5-nitro- 1-Nitrobenzene-3,5-dioarboxylic acid 5-Nitro-1,3-benzenedicarboxylic acid 5-Nitroisophthalic acid 5-Nitro-m-phthalic acid NSC 66545, Crystals mp = 260-261°. Lancaster Synthesis Co. Pfister. 

Scheme 3.37 describes gas-phase generation of m-benzyne anion (the distonic anion-biradical) from m-bis(trimethylsilyl) benzene (Wenthold et al. 1994, 1996 Wenthold and Squires 1998). The same anion-biradical is formed from isophthalic acid under the same conditions (Reed et al. 2000). Particularly, the reaction of m-bis(trimethylsilyl) benzene with fluoride ion, followed by treatment of the formed trimethylsilyl phenyl anion with fluorine in helium, produces the anion-biradical mentioned. The latter is transformed into the corresponding nitro benzoate anion through the addition of CO2 and NO2 (Scheme 3.37). 

The synthesis of ionic triiodinated contrast agents starts from either bisamino nitrophthalic acid or amino isophthalic acid. The nitro group is reduced to the amino moiety by hydrogenation. Iodine is introduced in aqueous solution with iodine monochloride. Due to the decrease in solubiHty the resulting triiodobenzene precipitates from the solution and can be recrystallised. Amino functions are then acylated. 

The use of the optimum pigment concentration, which can vary consideration, is equally important. Thus zinc salts of nitro-isophthalic acid are used at a concentration of ca. 0.5% by weight in paints, whereas ca. 90% is necessary in the case of zinc-dust pigments, to guarantee the zinc-iron contact necessary for cathodic protection. 

ISOPHTHALIC ACID (88-99-3) CgH O C4H4(COOH)j Combustible solid.Dust may form explosive mixture with air (flash point 334°F/168°C Fire Rating 1). Violent reaction with nitric acid forms explosive nitro materials in the presence of sulfuric acid. Dust and powder forms explosive mixture with air. Incompatible with strong acids, alkalis, aliphatic amines, alkanolamines, alkylene oxides, ammonia, epichlorohydrin, isocyanates, nitrates, nitromethane, sodium nitrite, strong oxidizers. On small fires, use dry chemical powder (such as Piuple-K-Powder), Halon , alcohol-resistant foam, water spray, or CO2 extinguishers. Coihbustion produces phthalic anhydride and carbon oxides. 

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