1. Field of the Invention
The present invention relates to an organophosphorus compound represented by formula (I): ##STR2## [wherein R.sup.1 and R.sup.2 each represent C.sub.1 to C.sub.4 alkyl; X represents O, S, CH.sub.2, CH--R.sup.3 (wherein R.sup.3 represents C.sub.1 to C.sub.3 alkyl), NH or NR.sup.4 (wherein R.sup.4 represents C.sub.1 to C.sub.4 alkyl, C.sub.1 to C.sub.4 alkyl substituted with at least one group selected from the group consisting of C.sub.1 to C.sub.3 alkoxy and halogen, C.sub.3 to C.sub.5 alkenyl or C.sub.3 to C.sub.5 alkynyl); Z represents C(CN)R.sup.5 (wherein R.sup.5 represents C.sub.1 to C.sub.3 alkylsulfonyl, C.sub.1 to C.sub.3 alkylsulfonyl substituted with halogen, C.sub.1 to C.sub.3 alkylcarbonyl, C.sub.1 to C.sub.3 alkylcarbonyl substituted with halogen, C.sub.1 to C.sub.4 alkoxycarbonyl, C.sub.1 to C.sub.4 alkoxycarbonyl substituted with halogen, C.sub.3 to C.sub.5 alkenyloxycarbonyl, C.sub.3 to C.sub.5 alkynyloxycarbonyl, C.sub.1 to C.sub.4 alkylthiocarbonyl, C.sub.1 to C.sub.3 monoalkylaminocarbonyl or C.sub.1 to C.sub.3 dialkylaminocarbonyl); and A represents ethylene, ethylene substituted with C.sub.1 to C.sub.3 alkyl, trimethylene, or trimethylene substituted with C.sub.1 to C.sub.3 alkyl].
The present invention also relates to a method for preparing the compound of formula (i), and insecticides, acaricides and nematocides which comprise the compound as an active ingredient.
2. Prior Art Statement
Recently, organophosphorus compounds having an imidazolidinyl group have been investigated and developed. For instance, Japanese Unexamined Patent Publication No. Sho 61-267594 and Japanese Unexamined Patent Publication No. Hei 2-793 disclose that these compounds can be used as insecticides, acaricides, nematocides and agents for killing soil insect pests. However, these patents simply disclose organophosphorus compounds having an imidazolidine skeleton which carries an oxygen or sulfur atom on the 2-position. Moreover, the insecticidal, acaricidal and nematocidal effects of these compounds are insufficient and are not necessarily satisfactory.