1,3,5-Triazapenta-1,4-dienes: Chemical aspects of a new group of pesticides

1,3,5-Triazapenta-1,4-dienes of formula Ar? N?CH? N(R)? CH?N? Ar′, are a new group of biologically active compounds. Various general methods for their preparation are described and their physical and chemical properties, including stability over range of pHs, are discussed. The unsymmetrical 1,3,5-triaza-penta-1,4-dienes(Ar≠Ar′) are unstable; insolution, particularly, they equilibrate to the corresponding stable symmetrical analogues. Structure-activity relationships in laboratory tests against Boophilus microplus and Tetranychus urticae are discussed. Problems in the synthesis of ring-¹⁴C]-amitraz,^b 1,5-di-(2,4-dimethylphenyl)-3-methyl-1,3,5-triazapenta-l,4-diene], an active member of the group, are outlined.