The reinvestigation of the kinetics of the reactions of fluorodi(4-nitrophenyl)ethanes with sodium methoxide in methanol

Abstract

The procedure previously described for the preparation of 1-fluoro-2,2,-di(4-nitrophenyl)ethane actually yields 1,1,2-tri-(4-nitrophenyl)ethane. 1-Fluoro-2,2-di(4-nitrophenyl)ethane has been prepared and rate constants, isotope effects, and activation parameters for the β-elimination reaction with methoxide ion in methanol are reported. These parameters indicate a concerted E2 mechanism, with a fairly symmetrical transition state. The subsequent dimerization reaction of the olefin product to yield 1,1,3,3-tetra(4-nitrophenyl)butene-1 is described.The reaction of 1,1,1-trifluoro-2,2-di(4-nitrophenyl)ethane with methoxide ion in methanol has been reinvestigated and the reaction of the first product 1,1-difluoro-2,2-di(4-nitrophenyl)ethylene with excess methoxide, to give di(4-nitrophenyl)ketene dimethylacetal in a multistep reaction, is reported.