KINETICS, DEUTERIUM-ISOTOPE EFFECT AND MECHANISM OF THE REACTION OF 1,1,1-TRIFLUORO-2,2-BIS(4-NITROPHENYL)ETHANE WITH 1,1,3,3-TETRAMETHYLGUANIDINE IN APROTIC-SOLVENTS

The reaction of 1,1,1-trifluoro-2,2-bis(4-nitrophenyl)ethane with 1,1,3,3-tetramethylguanidine (TMG) in different solvents gives N-[bis(dimethylamino)methylene]-1-fluoro-2,2-bis(4-nitrophenyl)ethenylamine {(O2NC6H4)2C = CF[N = C(NMe2)2]} as the final product. No intermediates were isolated in the reaction mixture. The kinetics of this reaction in a series of solvents-acetonitrile (MeCN), benzonitrile (PhCN), tetrahydrofuran (THF) and hexane-are reported. In acetonitrile kinetic curves showed non-exponential behaviour in the first 10-20% of the kinetic run. The rate constants, deuterium isotope effect and activation parameters are discussed in terms of a multistep mechanism. Non-exponential behaviour of kinetic curves in acetonitrile and the lack of intermediate is explained.