N‐acylation of N‐methylcarbamate insecticides and its effect on biological activity

N‐Acylated N‐methylcarbamates have been prepared and tested for contact/stomach poison and systemic insecticidal activities, mammalian toxicity and in vitro anticholinesterase activity. The N‐acyl derivatives in general have lower mammalian toxicities and somewhat lower insecticidal activities than the corresponding unacylated N‐methylcarbamates and are relatively poor inhibitors of bee cholinesterase. Tentative reasons are given for these effects.