Comparative evaluation of new synergists containing a butynyl-type synergophore group and piperonyl butoxide derivatives

Cross-substituted derivatives of piperonyl butoxide (PBO) and MB-599 (propo sed common name: verbutin) were synthesized and investigated as carbofuran and permethrin synergists against housefly, Musca domestica L. The majority of PBO and MB-599 derivatives were significantly more potent synergists fo r carbofuran than for permethrin. PBO, the most important representative of this series was not the most potent synergist for carbofuran or for permet hrin. Cleavage of the methylenedioxy ring of methylenedioxyphenyl (MDP) pol yether compounds resulted in complete loss of synergistic activity with bot h insecticides, but it could be restored or even improved by incorporating an alkynyl ether moiety into the molecule. The improved synergistic activit y was found to be closely associated with the 2-butynyloxymethyl side-chain , suggesting that this can be regarded as a characteristic synergophore gro up. MB-599, one of the most promising compounds bearing this group showed c onsiderably higher activity with carbofuran (synergist ratio, SR=37.8) than with PBO (SR=6.4). There was no significant difference between synergistic activities of MB-599 (SR=4.6) and PBO (SR=4) for permethrin. (C) 2001 Soci ety of Chemical Industry.