The present investigation has been achieved in accordance with the Diels-Alder reaction (1,4 cycloaddition) to produce a new halogenated bicyclic adduct. ortho-Bromoallylbenzoate is a new dienophile that was prepared in a pure form, and its structure was confirmed. The Diels-Alder syntheses of hexachlorocyclopentadiene and the new dienophile were studied to determine the optimum condensation reaction conditions under a temperature range of 90-160degreesC, reaction times of 1-8 h, and molar diene/dieno-phile ratios from 1:1 to 5:1 as a consequence. The optimum conditions reached were a temperature of 140degreesC, an initial diene/dienophile molar ratio of 3:1, and a duration time of 6 h. The maximum stoichometric yield under these optimum conditions (82.5%) was obtained. (C) 2003 Wiley Periodicals, Inc. Appl Polym Sci 89: 2331-2338, 2003.