ISSN 1017-2548(Print)
ISSN 2234-8530(Online)
Volume 19, Number 4
JKCSEZ 19(4)
August 20, 1975 

N,N-Diethyl-m-toluamide is the active ingredient in insect repellant against malaria mosquito. It is remarkable that if the methyl group is in either of the other isomeric positions(ortho or para) the compound is ineffective as an insect repellant. Semiempirical quantum mechanical treatment are applied to these molecules to explain the difference, using the extended Huckel theory, the theoretical predictions for the preferred conformation are compared with experimental results.