Abstract
Tris(dimethy1amino)phosphine 1 reacted with phenylarylidene barbituric acids 4 to yield the triaminophosphonium dipolar ion adduct 7. 2-Arylidene-1,3- cyclohexanedione 5 and 2-Arylidene-5,5-dimethylcyclohaxane1-,3 -diones 6 reacted with phosphine 1 to produce the dioxyxanthenes 10 and 12, respectively. Structural assignments are based on analytical, chemical, and spectroscopic evidences. A mechanism is proposed to explain the formation of these compounds. The biological acitivity of the new synthesized compounds against Aphis Craccivora, a serious pest infecting many crops in Egypt, was studied.