Acaricides tetrazines

Tetrazine acaricides are derivatives of tetrazine. Clofentezine is an acaricide/ovicide for eggs of various phytophagous mites on deciduous fruits, citrus, cotton, vines, and ornamentals. Its oral LD50 in rats is >5200 mg/kg. 

Bis(2-chlorophenyl)-l,2,4,5-tetrazine (lb) exhibits high activity against mites and is used as an acaricide (Chlofentezine). 

Scheme 26.2.1. Synthesis of the tetrazine acaricides clofentezine and diflovidazin.

Closely related is the development product diflovidazin (46 1996, Flumite , Chinoin) [108], a 1,2,4,5-tetrazine acaridde that contains the 2,6-difluorophenyl group as common feature of BPUs (cf. acaricidally active 37 and 39) and 46 (Fig. 35.11). The MoA of 46 involves inhibition of mite development at both the egg and chrysalis stages, but the mechanism by which this occurs has not been clarified [109]. The mite growth inhibitor clofentezine (47 1983, Apollo , Schering) [110] was launched as the first compound of the 1,2,4,5-tetrazine type. The design... 

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