Abstract: 12 α, α-Diphenyl-α-(2-diethylamino) ethyl acetates and 12 α- phenyl-α-cyclopentyl-α-(2-diethylamino) ethyl acetates were synthesized. The effects of polarity of solvents on the formation of carbanions and nucleophilic substitution reaction were studied during the synthesis of these compounds.In preliminary pharmacological tests some compounds showed marked analgesic action.