Claims
        
                - 1. A cyano compound of the formula (I) ##STR205## wherein R.sup.1 is hydrogen, methyl, ethyl or propyl,
 
                - m is 1
 
                - R.sup.2 is hydrogen, C.sub.1-6 alkyl,
 
                - R.sup.3 is ##STR206##  in which R.sup.4 is C.sub.1-6 alkyl R.sup.5 and R.sup.6 are hydrogen, C.sub.1-9 alkyl and in addition, R.sup.5 and R.sup.6 may form, together with the N-atom to which they are bonded, pyrrolidino, piperidino, 2-methylpiperidino, morpholino, piperazino or isoxazolidino, and Z is a 6 membered heterocyclic group which is substituted by halogen or C.sub.1-2 alkyl and contains one heteroatom N, as a ring member, provided that where Z is pyridyl substituted by halogen, m is 1, R.sup.2 is methyl, ethyl or propyl and R.sup.3 is --S-alkyl (C.sub.1-3) or --S-benzyl, then R.sup.1 is methyl, ethyl or propyl.
 
                - 2. A cyano compound according to claim 1, wherein such compound is S-methyl-N-(2-chloro-5-pyridylmethyl)-N'-cyanoisothiourea of the following formula: ##STR207## 3-(2-chloro-5-pyridylmethyl)-3-methyl-2-cyanoguanidine of the following formula: ##STR208## 3-(2-chloro-5-pyridylmethyl)-1-methyl-2-cyanoguanidine of the following formula: ##STR209## 3-(2-chloro-5-pyridylmethyl)-1,1-dimethyl-2-cyanoguanidine of the following formula: ##STR210## 3-(2-chloro-5-pyridylmethyl)-1,3-dimethyl-2-cyanoguanidine of the following formula: ##STR211## 3-(2-chloro-5-pyridylmethyl)-1,1,3-trimethyl-2-cyanoguanidine of the following formula: ##STR212##
 
                - 3. An insecticidal composition comprising an insecticidally effective amount of a cyano compound according to claim 1 in admixture with a diluent.
 
                - 4. A method of combating insects which comprises applying to insects or to a habitat of insects an insecticidally effective amount of a cyano compound according to claim 1.
 
                - 5. A method according to claim 4, wherein said cyano compound is
 
                - S-methyl-N-(2-chloro-5-pyridylmethyl)-N'-cyanoisothiourea,
 
                - 3-(2-chloro-5-pyridylmethyl)-3-methyl-2-cyanoguanidine, or
 
                - 3-(2-chloro-5-pyridylmethyl)-1-methyl-2-cyanoguanidine.
 
        
                        Priority Claims (2)
        
            
                
                    | Number | 
                    Date | 
                    Country | 
                    Kind | 
                
            
            
                    
                        | 63-264020 | 
                        Oct 1988 | 
                        JPX | 
                         | 
                    
                    
                        | 1-57813 | 
                        Mar 1989 | 
                        JPX | 
                         | 
                    
            
        
                        Parent Case Info
        This application is a continuation of application Ser. No. 419,428, filed 10/10/89, now abandoned.
                
                
                
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                            | Journal of Medicinal Chemistry, Aug. 1978 vol. 21, No. 8; Hans Jorgen Petersen, Synthesis and Hypotensive Activity of N-Alkyl-N"-Cyano-N'-Pyridylguanidines, pp. 773-781. |