Structure–activity relationship study of alkynyl ether insecticide synergists and the development of MB‐599 (verbutin)

Abstract

Structure-activity relationships of aryl alkynyl synergists of the general formula of Ar-Q-R, where Q represents a bridging structure, were studied using a standardised testing system and Relative Potency values. Ethers, esters, oxime ethers, amides and amines were prepared and evaluated. The length of the R-alkynyl chain, the role of the bridge and the substitution of the aromatic ring were examined systematically. The most potent compounds possessed an aromatic ring connected via a bridge of three atoms to an alkynyl chain, forming together a linear side-chain of six atoms. Several highly potent compounds were synthesised of which one (MB-599; proposed common name verbutin) was selected for development as a selective insecticide synergist in crop protection. Its high potential at practical insecticide:synergist ratios makes possible the reduction of the total amount of insect-control chemicals applied, and its use as an additive to produce new formulations of existing insecticides makes it highly advantageous in resistance management, giving a new tool to sustain the effectiveness of a wide range of insecticides. A product containing a (1+1) mixture of verbutin and beta-cypermethrin was launched in Hungary in 2002.

Persistent organic pollutants in coastal sediment off South China in relation to the importance of anthropogenic inputs

“…In Australia, the threat of pyrethroid resistance in H. armigera was countered by a maximum of two consecutive pyrethroid sprays to coincide with peak bollworm damage 23. In addition, more research is needed to screen effective enzyme inhibitors,47 and also organophosphates, which can be used as a tank mix with pyrethroids when showing negative or at least non‐cross‐resistance patterns to pyrethroids 48, 49…”

Esterase‐mediated resistance to pyrethroids in field populations of Helicoverpa armigera (Lepidoptera: Noctuidae) from Central Africa

“…In Australia, the threat of pyrethroid resistance in H. armigera was countered by a maximum of two consecutive pyrethroid sprays to coincide with peak bollworm damage. 23 In addition, more research is needed to screen effective enzyme inhibitors, 47 and also organophosphates, which can be used as a tank mix with pyrethroids when showing negative or at least non-cross-resistance patterns to pyrethroids. 48,49 Recommendations of mixtures with synergistic properties (e.g.…”

The interactions of piperonyl butoxide and analogues with the metabolic enzymes FE4 and CYP6CY3 of the green peach aphidMyzus persicae(Hemiptera: Aphididae)

“…Benzodioxole derivative 31 was synthesised according to Tozzi . Dimethoxybenzene derivatives 26 and 27 were synthesised according to Bertok et al …”

“…Technical PBO and analogues with modifications in the methylenedioxyphenyl (MDP) moiety, alkyl and polyether side chains were supplied by Endura SpA (Bologna, Italy) ( Tables 1 and 2 15 Benzodioxole and benzodioxane derivatives, 6 and 30 respectively, were synthesised according to Ugolini et al 16 Benzodioxole derivative 31 was synthesised according to Tozzi. 17 Dimethoxybenzene derivatives 26 and 27 were synthesised according to Bertok et al 18 Novel benzodioxole derivatives 32-35 and 37 and dihydrobenzofuran derivatives 39-42, 44, 46 and 47 were synthesised through a four-step synthesis, namely acylation with the corresponding anhydride, reduction, chloromethylation and etherification starting from commercially available benzodioxole and dihydrobenzofuran respectively. Derivatives 36 and 38 were synthesised starting from piperonal and piperonilic acid respectively through a condensation reaction with 2-(2-butoxyethoxy) ethanol under anhydrous conditions.…”