HALOFLUORINATION OF 1,2-DIFLUORO-1,2-DI(P-TOLYL)ETHENE, 1,2,3,4-TETRAFLUORO-1,4-DI(P-TOLYL)BUTADIENE AND ITS NONFLUORINATED PARENT COMPOUNDS

The reactions of (E)-1,2-difluoro-1,2-di (p-tolyl) ethene (1) with N-b romo- or N-chlorosuccinimide gave mainly the expected halofluorination products 1-bromo-1,2-di(p-tolyl)-1,2,2-triffuoroethane (2) or 1-chlor o-1,2-di(p-tolyl)-1,2,2-trifluoroethane (4), respectively. As a side r eaction halogenation of the double bond has been obtained. With -1,4-d i(p-tolyl)-1,2,3,4-tetrafluorobuta-1,3-diene (6) under the same condit ions the products of 1,2- and 1,4-addition or its consecutive hydrolys is products were isolated. (E)-Stilbene (19) on bromofluorination gave solely erythro-1-bromo-2-fluoro-1,2-diphenylethane (20), while with 1 ,4-diphenylbuta-1,3-diene (17) mainly higher molecular weight products were formed. (C) 1998 Elsevier Science S.A. All rights reserved.