New methods for the preparation of perfluoroalkyl- and perfluoroalkylether-s-triazines

Two new single-step processes are provided for the preparation of 2,4,6-tris(perfluoroalkyl) and (perfluoroalkylether)-1,3,5-triazines. One method involves the nucleophilic substitution of cyanuric fluoride with (perfluoroalkyl) and ( perfluoroalkylether) trimethylsilanes in the presence of cesium fluoride. Substituted s-triazines, 2,4,6-(R-f)(3)C3N3 (IIa-d) {IIa, R-f=n-C8F17; IIb, R-f=(CF3)(2)CFO(CF2)(4); IIc, R-f=C3F7OCF(CF3)CF2OCF(CF3); IId, R-f=C3F7O[CF(CF3)CF2O](2)CF(CF3)}, with either primary or secondary carbon atoms next to the ring can be produced by this method in reasonable yields, 41-77%. Using the second method, substituted triazines, IIa and IIb, are prepared by the cross-coupling reactions of cyanuric chloride with perfluoroalkyl and perfluoroalkylether iodides in the presence of copper powder. This method can only produce substituted triazines with primary carbon atoms adjacent to the ring. (C) 1998 Elsevier Science S.A. All rights reserved.