Chemotherapeutical agents. VII. Synthesis and pesticidal activities of sulphides and sulphones derived from bis[4‐aryl‐1,2,4‐triazoline‐5‐thione‐3‐yl]alkane and 5‐phenyl‐1,3,4‐oxadiazole‐2‐thione

The bis[4‐aryl‐3‐alkylthio‐1,2,4‐triazol‐5‐yl]alkanes 4 were prepared by the action of alkyl halides on bis[4‐aryl‐1,2,4‐triazoline‐5‐thione‐5‐yl]alkanes in aqueous sodium hydroxide (5%). The prepared sulphides 4 were oxidised to give the corresponding sulphones 5 either with acidic potassium permanganate or hydrogen peroxide. Similarly, sulphides 8 were prepared from 5‐phenyl‐1,3,4‐oxadiazole‐2‐thione by reaction with different alkylhalides in alkaline medium. Mannich bases 9 from 5‐phenyl‐1,3,4‐oxadiazole‐2‐thione (7) were also prepared by stirring an equimolar solution of 6 in ethanol with formaldehyde (38%) and an amine in an ice‐cold bath. All the compounds were screened for their pesticidal activities but none showed any significant activity.