| abstract |
N, N'-(halo)hydrocarbon -bis-tetrabromophthalimides are prepared by brominating a compound of the formula Z-R-Z (wherein each Z is a phthalimido group and R is a (halo)hydrocarbon) in 40-80% oleum, with or without a catalyst such as silver nitrate or iron/iodine. The designations "(halo)" and "(cyclo)" permit optional halogenation and cyclic character respectively. n In preferred embodiments of the invention, the N, N'-(halo) hydrocarbon-bis-phthalimide is an N, N'-(cyclo) alkylene-bis-phthalimide - most preferably N, N'-(1,2-ethylene) -bis-phthalimide, the brominating agent is bromine, and the ingredients are admixed in such amounts that the reaction mixture contains about 1-1.5 atoms of bromine and about 1-1.9 molecules of sulfur trioxide per available aromatic carbon atom in the N, N-(halo)hydrocarbon -bis-phthalimide. |