2644 (X= OMe) in an attempt to establish a Hammett relationship between the 4" Ibstituent and the chemosterilant activity of the compounds after oral administration to adult Musca domestica. Fourteen compounds of this type were prepared, 12 of them new. Jurd 2419 (X= H) was found to be as active in our bioassay as Jurd 2644, as were four new compounds [X= N (CH&, CH3, SCH3, Cll. All prevented successful reproduction at 30 mgkg of diet. There ...