An imidacloprid-related nitromethylene compound and its alkyl congeners at the imidazolidine NH site were prepared and their insecticidal and nerve-excitatory and -blocking activities were measured. In the insecticidal test with the male adult American cockroach by the injection method, metabolic inhibitors, more or less, increased the activity of tested compounds. The NH mother compound was the most active among the nitromethylene compounds and was as active as imidacloprid under the synergistic conditions. The N-alkyl congeners were less active than the NH compound under the conditions. In both of the nerve excitatory and blocking activities measured with a central nerve cord of the American cockroach, the NH compound was the most active among the nitromethylene series compounds and was less active than imidacloprid.A good correlation was not observed between the nerve activities. Quantitative analyses showed that the insecticidal activity measured with the metabolic inhibitors was better correlated with the nerve-blocking activity than with the nerve-excitatory activity. When factors of transport of the compounds within the insect body and/or interaction with target sites were considered separately by use of the hydrophobicity parameter, the correlation with the nerve-blocking activity was significantly improved.

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Bivalent molecules of bis-Imidacloprid with 2-10 alkylene tethers as well as tethers containing an ethenylene, ethynylene, phenylene and oxide joint were prepared. These dimeric chloronicotinyl molecules were highly Insecticidal against American cockroaches on injection at 2-30 nanomolar doses. The minimum lethal dose of the most potent hexamethylene derivative was close to that of imidacloprid, and the potency was augmented up to about thirty-five-fold following pretreatment with metabolic inhibitors, while the binding affinity to [3H] imidacloprid-binding sites on the nicotinic acetylcholine receptor was weaker than that of imidacloprid by a factor of 160. The hexamethylene derivative elicited impulses in cockroach central nerves with an initial excitation and subsequent block at a potency comparable to imidacloprid.