Tetrachlorophthahc anhydride

Halex technology has also been employed to prepare l,2,3,4-tetrafluoroben2ene derivatives, eg, tetrachlorophthahc anhydride [117-08-8] was converted to 2,3,4,5-tetrafluoroben2oic acid [1201 -31 -6] for use ia fluoroquiaoloae antibacterials (219,220). 

Chlorendic anhydride is the common name of the Diels-Alder adduct of maleic anhydride and hexachlorocyclopentadiene, 3,4,5,6,7,7-hexachloroendomethylene-l,2,3,6-tetrahydrophthahc anhydride (HET). The resultant resins from HET contribute to the flame retardancy of the alkyd coatings. HET gives a greater reaction rate than phthaUc anhydride, to the extent that at 204—210°C the reaction rate approximates that of phthaUc anhydride at a temperature of 238°C (8). However, the resins tend to develop darker color, particularly at high processing temperature. Tetrachlorophthahc anhydride [117-08-8] made by conventional chlorination of phthaUc anhydride, would also impart flame retardancy to its alkyds. However, it is appreciably less soluble in the usual processing solvents than is phthaUc anhydride, and is reported to be of appreciably lower chemical reactivity (8). 

VENABLES, K.M., TOPPING, M.D., NUNN, A.J., HOWE, W. NEWMAN TAYLOR, A.J. (1987) Immunologic and functional consequences of chemical (tetrachlorophthahc anhydride)-induced asthma after four years of avoidance of exposure. Journal of Allergy and Clinical Immunology, 80, 212-218. 

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