Organophosphorus compounds and insecticidal, acaricidal and nematocidal compositions containing same

Insecticidal, acaricidal or nematocidal compositions which comprise a series of organophosphorus compounds represented by the compounds represented by the following structural formulae: ##STR1## show excellent effect for controlling harmful insects, mites and nematodes, do not give off a bad or irritating odor and exhibit very low toxicity to warm-blooded animals.

BACKGROUND OF THE INVENTION (Field of the Invention) The present invention 
relates to an organophosphorus compound represented by the following 
general formula (I): 
##STR2## 
[wherein R.sup.1 and R.sup.2 each represents a C.sub.1 to C.sub.4 alkyl 
group; X represents O, S, CH.sub.2, CH--R.sup.3 (wherein R.sup.3 
represents a C.sub.1 to C.sub.3 alkyl group), NH or N--R.sup.4 {wherein 
R.sup.4 represents a C.sub.1 to C.sub.4 alkyl group (the alkyl group may 
be substituted with at least one group selected from the group consisting 
of alkoxy, alkylthio, cyano, alkoxyalkyloxy and alkylamino groups and 
halogen atoms), an alkenyl group which may be substituted with halogen 
atoms, an alkynyl group which may be substituted with halogen atoms, a 
phosphoric acid ester radical, a cyano group, a group of the following 
general formula (II): 
##STR3## 
(wherein R.sup.3 represents an alkyl or alkylamino group which may be 
substituted with halogen atoms) or a group represented by the following 
general formula: --(R.sup.6) , --CO--R.sup.7 (wherein n is 0 or 1; R.sup.6 
represents a methylene group which may be substituted with alkyl groups, 
or an ethylene group which may be substituted with alkyl groups; R.sup.7 
represents an alkyl group which may be substituted with halogen atoms, an 
alkoxy group which may be substituted with halogen atoms, an alkylthio 
group, an alkylamino group or a hydrogen atom}; Z represents a group 
represented by the general formula: N--R.sup.8 (R.sup.8 represents a nitro 
group, a cyano group, an alkylsulfonyl group which may be substituted with 
halogen atoms, a tosyl group or an alkylcarbonyl group which may be 
substituted with halogen atoms) or a group represented by the general 
formula: C(CN)R.sup.9 (wherein R.sup.9 represents a cyano group or an 
alkoxycarbonyl group); and A represents an ethylene group which may be 
substituted with C.sub.1 to C.sub.3 alkyl groups, a trimethylene group 
which may be substituted with C.sub.1 to C.sub.3 alkyl groups or a group 
represented by the general formula: --CH.sub.2 NR.sup.10 CH.sub.2 -- 
(wherein R.sup.10 is a C.sub.1 to C.sub.3 alkyl group)]. The compound of 
formula (I) according to the present invention specifically excludes an 
organophosphorus compound of the general formula (I) in which R.sup.1 and 
R.sup.2 are C.sub.1 to C.sub.4 alkyl groups respectively, X is NH, Z is a 
cyanoimino group or a nitroimino group and A is an ethylene group which 
may be substituted with C.sub.1 to C.sub.3 alkyl groups or a trimethylene 
group which may be substituted with C.sub.1 to C.sub.3 alkyl groups. 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. 
(Prior Art Statement) 
Recently, organophosphorus compounds having an imidazolidinyl group have 
been investigated and developed. For instance, Japanese Unexamined Patent 
Publication No. She 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. 
OBJECTS AND SUMMARY OF THE INVENTION 
Accordingly, an object of the present invention is to provide a novel 
organophosphorus compound represented by the foregoing general formula 
(I). 
Another object of the present invention is to provide a method for 
preparing a novel organophosphorus compound represented by the foregoing 
general formula (I). 
A further object of the present invention is to provide an agricultural 
chemical having insecticidal, acaricidal and nematocidal effects higher 
than those attained by conventional agricultural chemicals and exhibiting 
very low toxicity to warm-blooded animals. 
The inventors of this invention have synthesized a variety of 
organophosphorus compounds carrying an imidazolidinyl group and have 
investigated the insecticidal, acaricidal and nematocidal activities of 
the organophosphorus compounds having an imidazolidine skeleton which 
carries a specific substituent on the 2-position in order to develop 
effective insecticides, acaricides and nematocides. As a result, the 
inventors have found out that excellent control of harmful insect pests 
can be achieved by an organophosphorus compound (hereinafter referred to 
as "the compound of the present invention") represented by the following 
general formula (I): 
##STR4## 
[wherein R.sup.1 and R.sup.2 each represents a C.sub.1 to C.sub.4 alkyl 
group; X represents O, S, CH.sub.2, CH--R.sup.3 (wherein R.sup.3 
represents a C.sub.1 to C.sub.3 alkyl group), NH or N--R.sup.4 {wherein 
R.sup.4 represents a C.sub.1 to C.sub.4 alkyl group (the alkyl group may 
be substituted with at least one group selected from the group consisting 
of alkoxy, alkylthio, cyano, alkoxyalkyloxy and alkylamino groups and 
halogen atoms), an alkenyl group which may be substituted with halogen 
atoms, an alkynyl group which may be substituted with halogen atoms, a 
phosphoric acid ester radical, a cyano group, a group of the following 
general formula (II): 
##STR5## 
(wherein R.sup.3 represents an alkyl or alkylamino group which may be 
substituted with halogen atoms) or a group represented by the following 
general formula: --(R.sup.5) , --CO--R.sup.7 (wherein n is 0 or 1; R.sup.6 
represents a methylene group which may be substituted with alkyl groups, 
or an ethylene group which may be substituted with alkyl groups; R.sup.7 
represents an alkyl group which may be substituted with halogen atoms, an 
alkoxy group which may be substituted with halogen atoms, an alkylthio 
group, an alkylamino group or a hydrogen atom)}; Z represents a group 
represented by the general formula: N--R.sup.8 (R.sup.8 represents a nitro 
group, a cyano group, an alkylsulfonyl group which may be substituted with 
halogen atoms, a tosyl group or an alkylcarbonyl group which may be 
substituted with halogen atoms) or a group represented by the general 
formula: C(CN)R.sup.9 (wherein R.sup.9 represents a cyano group or an 
alkoxycarbonyl group); and A represents an ethylene group which may be 
substituted with C.sub.1 to C.sub.3 alkyl groups, a trimethylene group 
which may be substituted with C.sub.1 to C.sub.3 alkyl groups or a group 
represented by the general formula: --CH.sub.2 NR.sup.10 CH.sub.2 -- 
(wherein R.sup.10 is a C.sub.1 to C.sub.3 alkyl group)]. The compound of 
formula (I) according to the present invention specifically excludes an 
organophosphorus compound of the general formula (I) in which R.sup.1 and 
R.sup.2 are C.sub.1 to C.sub.4 alkyl groups respectively, X is NH, Z is a 
cyanoimino group or a nitroimino group and A is an ethylene group which 
may be substituted with C.sub.1 to C.sub.3 alkyl groups or a trimethylene 
group which may be substituted with C.sub.1 to C.sub.3 alkyl groups. Thus, 
the present invention has completed on the basis of the foregoing finding. 
These organophosphorus compounds do not give off any bad or irritating odor 
and have low toxicity to warm-blooded animals. Therefore, they can widely 
be used and thus have very high usefulness. 
The organophosphorus compounds represented by the foregoing general formula 
(I) also include stereoisomers such as optical isomers. In addition, in 
the general formula (I), when X is the group NH, the organophosphorus 
compounds may exist in the form of a tautomer represented by the following 
general formula (I'): 
##STR6## 
(wherein R.sup.1, R.sup.2, Z and A are the same as those defined above). 
These compounds (tautomeric isomers) are likewise included in the scope of 
the compound of the present invention.