The invention discloses a preparation method of
hexabromocyclododecane. The preparation method comprises three steps of bromination, washing separation and
drying, wherein the bromination step comprises the steps of respectively dropwise adding raw materials including
cyclododecatriene and
bromine into a mixed
solvent of
isobutanol and
dichloroethane, and heating to 50+ / -2 DEG C in three stages of the dropwise adding process, wherein the
molar ratio of
bromine to
cyclododecatriene is (3.05-3.08) to 1, and the total reaction time is 3-4 hours; the washing separation step comprises the steps of adding a
solid phase separated from a finished solution of the bromination reaction into the prepared mixed
solvent of
dichloroethane and
isobutanol, after uniformly stirring and mixing, separating the
solid phase out, adding
ethanol, and washing twice, so as to obtain the filtered
solid phase; the
drying step comprises the step of
drying the solid phase obtained in the washing separation step at 80+ / -2 DEG C, so as to obtain a white solid
powder product. According to the preparation method of
hexabromocyclododecane, completely-bromized impurities which are entrained by the product and can influence the
melting point are removed by virtue of a
solvent washing method, so that the product
impurity is improved, and the
melting point of products is increased.