HERSTELLUNG VON POLYFLUORBUTENEN.

摘要

Preparation of 1,1,1,2,4,4,4- heptafluorobutene-2 (i) and of 2-chloro-1,1,1,4,4,4- hexafluorobutene-2 (ii) simultaneously from hexachlorobutadiene (iii) is new. (iii) is reacted with hydrogen fluoride (5-100 mol. per mol. (iii)) in presence of catalytic amounts of titanium tetrahalide, antimony trihalide and/or antimony pentahalide or mixtures of different such halides (0.1-30 mol.% halide based on (iii)) at -20 to +200 deg.C. Commercial (iii) e.g. ex Aldrich Chem Co is reacted with pref. 10-50 mol/mol. (iii) dry commercial HF in presence of e.g. TiCl4, SbF3, SbF5 or mixts. of Sb halides or pref. SbCl5 at pref. 1-25 mol.% halide based on (iii). Temp. is initially e.g. -10 to +18 and then increased to e.g. 40-160 deg.C., then increased to e.g. 40-160 deg.C. Pressure can be that developed by reagents or achieved by e.g. N2. Reaction mix is stirred further 1-5 hrs. at final temp. (ii) and (ii), in varying ratios, generally more (ii) than (i), are isolated by phase separation and/or fractional distillation.