p-Trifluoromethyltolane andp-fluorotolane have been synthesized by the action of sodium or potassium amide in liquid ammonia onpara-substituted 1,1-diphenyl-2-bromoethylenes. The geometrical isomers of 1-(p-trifluoromethylphenyl)-1-phenyl-2-bromoethylene have been separated and their configurations assigned on the basis of dipole moment measurements.p-Trifluoromethyltolane has been converted to a dibromide, which on oxidation gave benzoic andp-trifluoromethylbenzoic acids. Both tolanes have been reduced to the correspondingly substituted 1,2-diphenylethanes.