Structure-activity relationship studies with mosquito repellent amides

A series of amide analogues of N,N-diethyl-m-toluamide (DEET) and N,N-diethylphenylacetamide (DEPA) were synthesized to study their mosquito repellency in relation to chemical structure and physical properties. None of these parameters (vapor pressure, lipophilicity, and molecular length) could be related to protection time. However, when the protection time of all five amides derived from the same carboxylic acid was expressed in terms of all three parameters together, excellent correlation was obtained.